1971 CB450 K4 Cafe Racer Build "Aseizja"

Banjo450DOHC

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Sacramento, California
I thought I'd make a thread to record some of the resto modding I am doing on "Aseizja" (I call it this as a joke because it seems like the last guy to work on it must have had "a seizure" halfway through building it and given up). My other stock oem build is called "The Magnum Opus" (for it shall be my masterpiece). The idea with these two builds is that Aseizja is my red headed step child that gets hand-me-downs and inexpensive fixes and creative mods and The Magnum Opus will be done as a perfect build with the more expensive newer parts.

Really this post is concerning Aseizja, which after replacing the right hand handlebar switch the electrical gremlins seem to at last be mostly dealt with. I also did the carb slide test (both carbs seem stellar), replaced the throttle cable, and rerouted the fuel lines in a safer and less resistant manner.

It seems like now the only thing is if I really open up the throttle on it I can get the clutch to slip. I already adjusted the clutch and made sure that the first third of the handle has play like the FSM says to do, I checked the oil and added a bit to top it off and some zinc additive when I first got the bike, but since I have been waiting on the magnetic drain plug to arrive I haven't changed the oil yet so I'm going to do that before I start trying to repair the clutch since I know incorrect oil type can cause slippage and for all I know the previous guy used the wrong stuff.

He definitely had the clutch adjusted way too tight, there was no play in the handlebar lever and when I adjusted using the flathead on the engine side location it was jammed so tightly clockwise I almost couldn't get it loose. My only hope is that because he obviously barely rode this bike at all that the clutch discs didn't get too damaged.

If the clutch still gives me trouble after the oil change and zinc additive is done then I might end up trying swapping out the discs with the old discs from the magnum opus because it's clutch was working fine I'm just replacing the clutch discs and springs while I'm in the engine block for the rebuild work so they should be fine.

Also in regards to the transmission, the shift lever rod has way to much play you can grab the shaft and tug it back and forth about an inch with the shifter lever and cover removed. I pulled the c clip and washer at the base of the shift rod and cleaned it all out and got it installed better than previously and got some of the play out. Then I was able to use a flathead to open the shift lever enough to slide it further down the rod than I otherwise could have (because of the play it runs away from you as you try to put on the lever) and then I did a zip tie to close the small gap still left like the previous guy did.

With that mod I was able to get the bike to where it shifts just fine except for when you're trying to shift it into neutral when you're at a dead stop and the engine is running. I imagine this is probably a broken shifting fork or some such? I thought I'd ask if anyone's dealt with it and how hard it is to solve. If it's too pricey I may just ignore it and keep using it as is. It's not too hard to compensate with the clutch and by shifting into neutral early and coasting to a stop. I'd love to fix it properly if it's not super expensive though.

One mystery item is the lowbeam on the headlight works, but when I attach the white wire for it coming off of the handlebar it stays on continuously no matter what position the headlight switch is on. Mind you this is a brand new handle bar switch box as well. I also did the yellow/white wire mod to make the full stator run continuously, not just full when the headlights are on and half when they are off like I'm lead to believe it runs stock.

Also the rear tire blew out on my test drive last weekend, it's fine I was able to safely pull off the road and get a AAA tow no problem. I think I'm going to swap out both inner tubes and tighten up the spokes and clean up and clear coat the rims on the inside to prevent rust build up.

Also the previous guy removed every last reflector and blinker and painted EVERYTHING on this bike black. Including some electrical connections... I plan on going through with my dremel tool with brass wire brush attachments and polishing off as much of the chrome as I can to make the bike more reflective and pretty. At least the wheels and horn and maybe the engine itself. I think I might even add some yellow LED strips to make sure it's super visible at night since it would be easy and cheap to do.

Eventually I would love to add blinkers back to it (the wiring for them is still there) and reflector circles maybe too. I really prefer to be as visible as possible while riding and it looks great to me anyhow. I already took the old beat up mirrors off of The Magnum Opus and threw them on it which dramatically improved my visibility. Honesty if someone out there has fenders for it I'd even love to throw those back on it someday perhaps too.

I also definitely am not enjoying the low handle bars, I think I'll throw some stock ones back on it eventually or even some riser bars to bring them up a bit from stock height, probably at the same time I do my front forks since I'll need to pull the front wheel and such to remove the modded handlebars off it anyways.

Seen here below “Aseizja” (only cost me $200 on craigslist):
IMG_0019.jpeg

And seen here below is “The Magnum Opus” (even angels weep at her beauteous visage):

IMG_6101.jpeg
 
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Also in regards to the transmission, the shift lever rod has way to much play you can grab the shaft and tug it back and forth about an inch with the shifter lever and cover removed. I pulled the c clip and washer at the base of the shift rod and cleaned it all out and got it installed better than previously and got some of the play out. Then I was able to use a flathead to open the shift lever enough to slide it further down the rod than I otherwise could have (because of the play it runs away from you as you try to put on the lever) and then I did a zip tie to close the small gap still left like the previous guy did.
Member @birdland had a similar issue and took up the play using a locking collar. See post #45 in the link below.

The difficulty finding neutral could be some worn parts, specifically items # 11, 15 and 8 that are part of the shift drum mechanism located behind the clutch. When you go in to inspect the clutch, check for play with the rollers of parts #11 and 15 and for wear on part 8.
1765247605124.png

This is what part #8 wear looks like. Unfortunately this part is no longer available and very hard to locate in good condition.
1765248081247.png
 
Member @birdland had a similar issue and took up the play using a locking collar. See post #45 in the link below.
Wow! Thank you this is amazing. Exactly the solution I was looking for. I asked him where he got the lock collar I will definitely be getting one of my own.

The difficulty finding neutral could be some worn parts, specifically items # 11, 15 and 8 that are part of the shift drum mechanism located behind the clutch. When you go in to inspect the clutch, check for play with the rollers of parts #11 and 15 and for wear on part 8.
This makes a lot of sense also because on my brief inspection of the shift drum mechanism when I cleaned and regreased it it looks pretty long in the tooth. I'll definitely be inspecting it closer to look for the cause. I'll take pics when I do and reply on here with them.
 
Wow! Thank you this is amazing. Exactly the solution I was looking for. I asked him where he got the lock collar I will definitely be getting one of my own.


This makes a lot of sense also because on my brief inspection of the shift drum mechanism when I cleaned and regreased it it looks pretty long in the tooth. I'll definitely be inspecting it closer to look for the cause. I'll take pics when I do and reply on here with them.
I used the same thing for mine. You can find the collar at Ace Hardware, Tractor Supply and the big orange box - these are all SAE that you’ll have to bore out.

Or order on McMaster-Carr for metric.
 
So the rear inner tube blew last weekend on Aseizja. I pulled the rear wheel and tightened the spokes by ear and I'm cleaning up the inner wheel's small surface rust and then I'll use some clear coat to seal it off after I'm done polishing it. I am replacing and inspecting the rear brake drums while I have the wheel off and it looks like the shoes got stuck to the inside of the drum, how should I go about unsticking them and cleaning it up? Here's a picture of it:
IMG_0119.jpeg
Also I was able to do the metric collar over the shifter rod in front of the washer and it worked super well. Very solid, what a great tip and easy fix (edit: sadly this cured the play issue but caused the bike not to be able to shift into neutral anymore so i had to remove the collar later and go back to the zip tie). Here's a picture:

IMG_0118.jpeg
 
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Are you talking about the red rusty area where I marked with red arrows. I think that is the steel braking surface and does not look like the shoe material is stuck there just rusty. I used brake cleaner and a wire wheel on a drill to get the worst off and then used sandpaper to finish off om mine which was rusty as well.

Copy-0119.jpeg
 
Are you talking about the red rusty area where I marked with red arrows. I think that is the steel braking surface and does not look like the shoe material is stuck there just rusty. I used brake cleaner and a wire wheel on a drill to get the worst off and then used sandpaper to finish off om mine which was rusty as well.

View attachment 53453
Okay! Excellent! I honestly couldn't tell thanks for confirming. I'll wire wheel it clean and then do the sandpaper resurfacing on it. What grit sand paper should I use again? I forget right now.

I ended up doing 220 grit then 400 and then 0000 steel wool at the end. Took a while because it was so scraped and rusted but it cleaned up okay I think! Got it to where you can just barely feel the scratches in it now.
 
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I think I used some 120 grit taped to one of the old shoes that I used it as a sanding block. I didn't try to make it perfect just clean it up a bit. Be sure to clean up the entire hub with brake clean to get rid of any abrasive particles. New shoes and be sure to lube the shoe pivot cam and posts properly when assembling. Use the FSM.
 
Don't forget to arc the brake shoes for a good fit.
 
think I used some 120 grit taped to one of the old shoes that I used it as a sanding block. I didn't try to make it perfect just clean it up a bit. Be sure to clean up the entire hub with brake clean to get rid of any abrasive particles. New shoes and be sure to lube the shoe pivot cam and posts properly when assembling. Use the FSM.
Yup, this is what I did. I was careful the lube didn't get on the shoes too.

Don't forget to arc the brake shoes for a good fit.
This is fascinating, I've never heard of it. Looks like it's essentially that you're grinding them down? My install is already finished but I'll keep it in mind for the next one. Seems like I should use my back brake extra for a few hundred miles to try and even out the surface.
 
Yes that is a good idea, as you are riding (with no one behind you) lightly apply the rear brake off and on just to help bed the shoes in. Be sure not to over do it it and over heat the brakes.
 
Hey y'alls, quick update after about three days straight of working on Aseizja this weekend I got it road worthy! Finally riding it to work now. While I was working on the rear end I pulled the drivechain and hit it with some pb blaster and a wire brush to try and clean it up before I reinstalled it. I could feel a section of the links they were a bit crusty although they still had motion.

When I redid the chain adjustment I went a bit more tight on it down to about 3/4 and inch of slack, rather than the almost an inch I was giving it on the last adjustment. I think adjusting the chain must be what did it because now it doesn't slip even in high RPMs I can rev it up and it has no troubles at all.

On top of that I figured out that the guy before me must have painted over the handlebars and that is why the throttle was being so chunky and not smooth. I sanded down the handle bar where the throttle sleeve rides and then installed a new throttle sleeve with a bit of chain lube inside it and wow the throttle action is really smooth now.

I also was able to install the old foggy Tach from the Magnum Opus plus the new speedo I got off of ebay. I haven't figured out a way to mount it yet as the 350 mounting bracket that came with the gauges was a bit too small (Just as one of y'alls predicted) however I was able to zip tie it in place for the mean time while I look for a new bracket or some other way to mount the gauges.

Also sadly putting a collar on the shift rod prevented the bike from shifting into neutral at all! I had to remove the collar and go back to the zip tie method, strange as it is the bike does fine with this method as long as you shift into neutral before the bike is completely stopped.


Also I put in a new regulator/rectifier combo and holy hell the bike really woke up with that mod. Always amazes me how much more power that wakes up in these old bikes. It's about twice as loud and powerful now. That being said I have noticed that when I get it back to the trickle charger after a ride it seems to charge for a excessively long time, I may need to check the voltage on things and make sure the stator is still working like it should.

I also wired up the LED lights this weekend. They work really well and were easy enough to zip tie under the gas tank and seat on the frame. Wired them into my brake lights so they turn red when I hit the brakes. As soon as the new handlebar switch for the left side arrives I will wire the blinkers into them as well. For now I mostly am not running the LEDs though because I'm worried about the stator still.

Next thing for this bike definitely will be to change the front inner tube, wire brush the wheel and clear coat it for rust protection, and tighten the spokes and swap out the front disc brake pad.

Also it looks like the swing arm is in a poor state, I can feel maybe a couple millimeters of lateral play in it with the bike on the center stand and I think I can feel a slight sway in the rear while I'm riding around. Of course I'm staying off the main roads and keeping it low speed and wearing all my safety gear. I think as soon as I finish the magnum opus engine and have the magnum opus running again I'll do the swing arm on Aseizja.
 
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I think I can feel a slight sway in the rear while I'm riding around.
It might be the swing arm bushings, #10 in the parts fiche below. Could also be your rear shocks if they are original.
1765835739688.png

I replaced my bushings with a set from CBX performance.
 
It might be the swing arm bushings, #10 in the parts fiche below. Could also be your rear shocks if they are original.
View attachment 53561

I replaced my bushings with a set from CBX performance.
Excellent! I've been looking for this type of solution. I was reading up on some of the difficult experiences guys have had on here with worn bushings being stuck. I know Ancientdad said on a post or two that he ended up needing to replace one of his entirely. I didn't realize it could be shocks, it has a very clapped out set of oem shocks on it to the best of my knowledge so it's possible.

Is there a test I can do to see if it's the shocks or the swing arm bushing? Or both?
 
Is there a test I can do to see if it's the shocks or the swing arm bushing? Or both?
With the bike sitting on its wheels, grab the rear tire at the back and the frame behind the engine and try to move the rear wheel side to side, if the bushings are still original (and I'd be surprised if they weren't) then there will probably be some lateral movement of the rear wheel.
 
Simple thing, but make sure you check your tire pressures too in regards to the swaying. I went nuts trying to find a weird feeling in my bike only to notice the tires were somewhat lower than the spec.
 
Simple thing, but make sure you check your tire pressures too in regards to the swaying. I went nuts trying to find a weird feeling in my bike only to notice the tires were somewhat lower than the spec.
Yeah I have been checking them religiously. I try to set them on the dot at 28 psi for the front and 30 for the rear just like I saw in the FSM I believe it was.
 
With the bike sitting on its wheels, grab the rear tire at the back and the frame behind the engine and try to move the rear wheel side to side, if the bushings are still original (and I'd be surprised if they weren't) then there will probably be some lateral movement of the rear wheel.
This is the test I did that showed a mm or two of play. I was asking if there's a way to check if it's the shocks vs the bushing since Boddy mentioned bad shocks might also cause play.
 
This is the test I did that showed a mm or two of play. I was asking if there's a way to check if it's the shocks vs the bushing since Boddy mentioned bad shocks might also cause play.
Shocks only control up/down movement, since they're rubber mounted there's no way they could control side to side. However one weak shock or one frozen shock could result in a swing arm twisting.
 
Shocks only control up/down movement, since they're rubber mounted there's no way they could control side to side. However one weak shock or one frozen shock could result in a swing arm twisting.
Ah ha! That was my understanding of the situation. Thanks for confirming. My plan is to put the oem shocks from the Magnum Opus onto this bike as they are in decent shape but I will be upgrading them soon anyhow. I guess I'll see then if it's shock related for sure.
 
Hey Y'alls,

Just gonna give you guys a brief update on what I've done to the bike recently and then I'm hoping maybe I could get some advice and input on a couple of issues I'm still having.

I swapped out the inner tubes, adjusted the wheel spokes, replaced the rim strips, put in new spokes and chain (I went with a 14 tooth front spoke and the stock 35 tooth rear spoke for the torque and it's been amazing) I also removed the old handle bars and put stock style high riser bars with fresh rubber dampers in which has improved the handling and usability night and day for me. I also changed the lube in the front forks out (the old fluid was very nasty it clearly hadn't been changed in ages) I used 15w oil on the front fork. I also changed the oil, cleaned the oiler cup (it had a mm of gunk in it in some sections but it wasn't very thick or chunky it gave me the impression this engine hasn't been used very heavily) I also changed the oil plug to a magnetic oil plug. I also realized while reading the FSM that the throttle needs to have some degree of play in it from rest and made that final adjustment which really helped make things run correctly on that end.

I also sanded down the chambers of the carbs one in particular was a bit gunked up and wasn't going up and down smoothly when I blew on it like it should. I blew on the white plastic bits on the top of the carburators and they seemed leaky so I epoxied over them both to seal them just to be sure which seemed to really make everything start working like it should. I also replaced the float bowl gaskets and the air chamber gaskets on both carbs. This was one of the most power enhancing mods I've done yet after I did the carb work this bike really ripped me out of my seat it was amazing. There's just one problem: under very specific circumstances, usually at full wide open throttle especially at about 65 mph it will still do this bogging down thing where it seems like it's being fuel starved or something. All the sudden you lose power and it bogs and as you let off the throttle and treat it more gently it tends to be fine again but you can open up the throttle completely and make it bog deliberately almost always and especially when at 65 mph for some reason. Initially it did this at all speeds even idle but after the carb work I did it woke everything up and feels like it's running perfectly until that point at 65 mph where it starts starving/bogging/stuttering the more you open the throttle rapidly the more it starves, and the more gentle you are the less it's an issue at all. This is sort of my last snaffu on this bike's performance the last big mystery. Please share any ideas y'alls have. I'll drop some updated pics of the bike how it is now too.

I also wired in some amazon LED lights and zip tied them to the frame. I wired them into the brake light circuit I usually leave them on green so people can see me and then they flash red when I hit the brakes. They also have the ability to be used as blinkers where they will flash amber on the left or right side. The difficulty I'm having with this is that the previous builder on this bike completely removed all of the running lights and blinkers. I'm having some troubles understanding the running light/blinker circuit even though I am looking at the wiring diagrams. I've found the wires in the headlight bucket which lead to the rear of the bike still for left and right blinkers, it's just when I hook everything up I can only get it to work through left or right one at a time and never flashing like I'd like it too. Sorry this is scatterbrained, I realize I should have organized my thoughts more feel free to ask me questions on it.

IMG_0413.jpeg
 
On the bogging issue have you confirmed that the gas cap is venting properly? If the vent is partially plugged that might explain it. Another thing to look at is if the petcock screen is partially plugged and if you have added fuel filters they might be plugged or they just do not allow enough fuel flow even if clean.

Also there is an old saying that a lot of carb problems are electrical so take a look at the ignition system if nothing on the carbs stand out.
 
Adding to @RobMan's suggestions, I will mention something that happened with my CB450. If the throttle cables are not well synched and one throttle is opening earlier than the other, you can drain one bowl to the point that it will bog down (fuel starvation) when you're accelerating near wide open throttle. I could lay off and then go again until the fuel level got too low again or I could accelerate more gradually without issue. I felt dumb when I realized the problem.

I always think of this when someone mentions a motor bogging down at wide throttle, but so far everyone I mentioned this to was careful to synch their throttle cables.
 
gas cap is venting properly
This was one of my guesses as well, I'm not sure how to check the vent on this aftermarket tank besides just making sure the cap isn't screwed down too tight. I did google if this tank comes with a vent and it said yes, for what that's worth.
Another thing to look at is if the petcock screen is partially plugged and if you have added fuel filters they might be plugged
I did remove an extra fuel filter that was in the gas line initially. I also checked the petcock screen and it's clean as a whistle since this is a relatively new aftermarket tank.

If the throttle cables are not well synched and one throttle is opening earlier than the other, you can drain one bowl to the point that it will bog down (fuel starvation) when you're accelerating near wide open throttle.
I think I have experienced this before, on my other 450 when I was initially doing it's carbs and throttle cables earlier on. It's a good suggestion. I did the "guitar string method" in my case the banjo string method on the carbs for the magnum opus synch, and then of course finished the synch by synching up both cables visually opening and closing the throttle and making adjustments until they were in synch. I have synched the carbs and set up a fresh throttle cable on this bike, but I did not do the banjo string method as the idle synch seems to be fine already and the bike sounded good to me. I'm probably going to do the banjo string synch on the carbs now just to be extra certain they are synched. I would think that synching them visually on the cable would be the only synch related to this issue though since the banjo string method is more for setting the idle synch as far as I understand.

I took it for another ride and I also think the float bowl draining out theory is making a lot of sense because it runs righteously for a bit and then it starts to stutter and bog, not consistently on one side or the other though and when you give it just a few seconds to recover you can get on it again for a bit. This makes me wonder if it really is the synch causing the bog or if maybe it's still a the problem of this aftermarket gas tank is basically a CB125 tank with only a single nipple on the petcock rather than two and a smaller diameter nipple as well which to make up for the change in fuel line size and lack of dual lines there is a T fitting which also is probably restrictive. I still haven't thought of a good solution as I need to find a dual nipple petcock which is in my tank's smaller than stock 450 petcock diameter size. Maybe I'm barking up the wrong tree but I'm guessing it's starving out the float bowls to where with enough time they can refill just fine but under a lot of pressure at constant WOT they start really starving and go dry intermittently.
 
I think you're on the right track. If you can think of a way to eliminate or test the gas cap vent as you and Rob were thinking, that would help narrow things down.

Maybe a rubber plug with a small hole drilled in it?
 
Also there is an old saying that a lot of carb problems are electrical so take a look at the ignition system if nothing on the carbs stand out.
RobMan you called it on this one I think! Great advice.

I was riding home last week from work and the bogging down became more severe until finally the bike shut off and woudln't start again. As soon as I stopped I checked the ignition wires and I could immediately see the wires coming from the key switch were shorting out against the frame:

Wiring Short A.JPEG

As I dug into the wires and removed electrical tape the problem became more and more dramatic. Basically all four wires leading into the key switch were melted together almost completely fused. As I removed them and traced them back I found that the previous owner had been a real buffoon with the wiring. They had run jumper wires from the switch to the main harness with nothing but a twist on each end and some electrical tape to cover it up. So there were four terrible connections and lots of places the wires had melted together. The melting goes all the way back into the key switch. Luckily the wires seemed to be fine about in the area they join into the main wiring harness they go back to good properly insulated wires.

I also found where they had removed the fuse near the battery and simply cut and twisted the wires together and covered them in electrical tape and a housing style wire cap. I put a modern blade style fuse holder with a 15 amp fuse in the spot the fuse originally went. My plan is to put in a new key switch and proper fresh wires from the switch to the main harness. Perhaps I'll use spade connectors because the original round style plug/harness is completely gone now and I'm not sure it's worth buying the other half of the connector on ebay for this bike but I'd love to be able to disconnect the wires in the future if I need.

I'm looking for any other grounding out spots or melted wires just in case. I figure I'll test the charging system thoroughly once I get it up and running again and if the new fuse blows I'll know I still have a short. Just wanted to drop a line for you guys to give me input on whether I'm correct in my plans to fix this. Here's some more pictures of the damage from Bubba's Tom Foolery:
Wiring Short (1).JPGWiring Short (2).JPGWiring Short (12).JPGWiring Short (14).JPGWiring Short (3).JPGWiring Short (11).JPG
 
Yikes, when I said that I was thinking more of a bad condenser, coil, a loose connector or something along those lines. I concur with @boddy on the harness, if you find more than a couple of bad spots then there are probably more hiding in that harness. With more than a little experience trouble shooting and fixing electrical problems on vehicles I got a new harness from Sparck Moto and and had zero regrets on getting a new one. Also whatever you decide to do check your grounds especially where they connect to the frame for corrosion and bad terminals. Adding an extra ground or two is also good insurance against future problems.
 
That harness looks like it has taken a lot of abuse. Maybe time to replace it completely. Our sponsor Sparck Moto has one for the CB450
The bike came with a harness, I just haven't had the time to replace it. Is it difficult to replace with the tank and seat off? I've mostly just been avoiding doing the swap at the moment because of how much time I reckon it will take me to swap. The starter is already disconnected anyhow so I imagine that won't be a big factor in the swap but as far as the rest of the harness goes I'm just not sure how difficult and time consuming it is. Am I just overthinking it and it's a pretty easy swap? Or does it get tricky?

As far as the grounds go the previous owner switched out the headlight to a aftermarket LED headlight bucket and all and did not do anything to set up a ground to replace the headlight ground. When I first got the bike I discovered this and I set up a ground using a eyelet connecter into one of the fork bolts which I used a testing light to make sure was a good ground.
 
RobMan you called it on this one I think! Great advice.

I was riding home last week from work and the bogging down became more severe until finally the bike shut off and woudln't start again. As soon as I stopped I checked the ignition wires and I could immediately see the wires coming from the key switch were shorting out against the frame:

As I dug into the wires and removed electrical tape the problem became more and more dramatic. Basically all four wires leading into the key switch were melted together almost completely fused. As I removed them and traced them back I found that the previous owner had been a real buffoon with the wiring. They had run jumper wires from the switch to the main harness with nothing but a twist on each end and some electrical tape to cover it up. So there were four terrible connections and lots of places the wires had melted together. The melting goes all the way back into the key switch. Luckily the wires seemed to be fine about in the area they join into the main wiring harness they go back to good properly insulated wires.

I also found where they had removed the fuse near the battery and simply cut and twisted the wires together and covered them in electrical tape and a housing style wire cap. I put a modern blade style fuse holder with a 15 amp fuse in the spot the fuse originally went. My plan is to put in a new key switch and proper fresh wires from the switch to the main harness. Perhaps I'll use spade connectors because the original round style plug/harness is completely gone now and I'm not sure it's worth buying the other half of the connector on ebay for this bike but I'd love to be able to disconnect the wires in the future if I need.

I'm looking for any other grounding out spots or melted wires just in case. I figure I'll test the charging system thoroughly once I get it up and running again and if the new fuse blows I'll know I still have a short. Just wanted to drop a line for you guys to give me input on whether I'm correct in my plans to fix this. Here's some more pictures of the damage from Bubba's Tom Foolery:
The wiring "work" was with the same level of effort put into the "paint everything black including all the bolts"
 
The bike came with a harness, I just haven't had the time to replace it. Is it difficult to replace with the tank and seat off? I've mostly just been avoiding doing the swap at the moment because of how much time I reckon it will take me to swap. The starter is already disconnected anyhow so I imagine that won't be a big factor in the swap but as far as the rest of the harness goes I'm just not sure how difficult and time consuming it is. Am I just overthinking it and it's a pretty easy swap? Or does it get tricky?

As far as the grounds go the previous owner switched out the headlight to a aftermarket LED headlight bucket and all and did not do anything to set up a ground to replace the headlight ground. When I first got the bike I discovered this and I set up a ground using an eyelet connecter into one of the fork bolts which I used a testing light to make sure was a good ground.
With the tank and seat off it’s much easier. The headlight bucket is where a ton of photos come in handy. Start there and work your way back.

Keep a wiring diagram and a VOM handy.
 
The bike came with a harness, I just haven't had the time to replace it. Is it difficult to replace with the tank and seat off?
It's not too difficult to replace. With the tanks and seat off you will be able to get at everything. The main harness runs along the top of the frame with the bulk of the connections happening in the headlight bucket. There will be bundles of wires branching off at different places for the ignition switch, points/horn, alternator/battery, rectifier/regulator, tail light and rear flashers. You can sort of see this in the parts fiche for the wire harness. Just take pictures of the routing of your current harness as a guide.

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Excellent, sounds like a really smart gameplan for me to follow on this. I wonder if the harness I got with the bike is up to snuff though, or if I should buy one of the ones you guys are recommending. It's brand new in the package but I'm very suspicious of everything I got from the previous owners. I'll see if it's still got a part number on it somewhere and inspect it more thoroughly tonight, maybe upload some pictures of it and the part number to see what you guys think if it's up to snuff or not. I will double check that the wires are color coded correctly and the harness ends all look correct too.
 
Excellent, sounds like a really smart gameplan for me to follow on this. I wonder if the harness I got with the bike is up to snuff though, or if I should buy one of the ones you guys are recommending. It's brand new in the package but I'm very suspicious of everything I got from the previous owners. I'll see if it's still got a part number on it somewhere and inspect it more thoroughly tonight, maybe upload some pictures of it and the part number to see what you guys think if it's up to snuff or not. I will double check that the wires are color coded correctly and the harness ends all look correct too.
The base harness for pretty much all the bikes in that era is almost universal. The “backbone” of the electrical system is really consistent.

There’s zero chance it’s worse than what’s on there currently. There aren’t enough synonyms for “cooked” for that one.

As long as it has black, red and green - everything else is just accessories.
 
Alrighty got a quick update after I got a chance to work on the bike some more after work yesterday. At this point I'm calling it sabotage what the PO did to the wiring on this bike! This guy had the audacity to remove the central ground that goes underneath the rear fuel tank mount and use a housing style wiring connector to cap it off:

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I really appreciate your guys' advice, this surely saved me a lot of time and headaches to replace the harness right away. I wouldn't have found this missing ground otherwise for a long time probably. Between this ground and the two headlight bolt grounds he removed and the fuse he cut out it's a wonder this bike ever ran at all. Probably was running mostly off of the ground I added and perhaps some other grounds I'm not aware of yet.

Sadly the new harness is definitely not color matched exactly, and it does have some poor quality connectors that seem to be incorrect size for the spades on the bike currently. So far I have just been splicing my old connectors onto the new harness in the spots it's required. It's only needed a couple to be swapped out but it's annoying trying to guess at the colors. I'm mainly having trouble wiring up the "white/yellow" wire mod because there are no plain white wires on the new harness. I'll need to do it the slow way with a volt meter I imagine. For now I've got the old harness removed and the new one mocked into place with a few zip ties.

Here is a photo of the new harness pre installation:

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Also one thing that is bothering me is that the plug on the new harness did plug into the new key switch plug, however it just slides in and out of it there's nothing holding the plugs together, I had to use a zip tie gently strung around them to hold them together. Do the stock harnesses have some sort of catch or mechanism that holds them together? Or is a zip tie usually needed like this?
 
That's not a factory ground anyway. The original harness was notably deficient in this regard. as for actually running, the only thing the engine needs is the battery grounded to the engine block, and some 12v to the coil.

The harness you have is either a "universal" retrofit, or designed for the later CB450SC (Nighthawk) which is totally usable with the right modifications - it's going to have a couple of extras though, and won't be a direct plug and play.

The ignition switch plug does just pressure fit. Many have replaced those with modern terminal blocks.

Personally, I'd remove the sheathing and start by laying out the harness to match up to the factory wiring diagram at the back of the FSM. This will allow you to remove the extras, as well as go ahead and make the changes you'll need for a modern rec/reg and do the yellow/white tie in prior to the main harness. You can always rewrap that.
 
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Awesome beautiful, thank you EZpete. Up until now I've mostly done wiring by trial and error and mimickery more than actually following wiring diagrams. Definitely seems like the situation calls for it though and I've been looking for a chance to get some hands on practice with wiring diagrams anyhow. I have a nice color wiring diagram in my clymer manual I can use to figure things out as well. I have been reticent to remove the wrapping because I want the good insulation, I guess I should go buy some proper heat shrink down at oreillys or something and remove the sheathing on this so I can do this properly though.

If I'm reading your diagram correctly, yellow comes off of the regulator/rectifier (I did swap mine to a modern combo one) and the white wire is the headlight low beam? I'm trying to gain a better understanding of that mod. I know it tells the stator to give it full charge at all times and not just when the headlights are on, I'm just not sure how that's accomplished.
 
Awesome beautiful, thank you EZpete. Up until now I've mostly done wiring by trial and error and mimickery more than actually following wiring diagrams. Definitely seems like the situation calls for it though and I've been looking for a chance to get some hands on practice with wiring diagrams anyhow. I have a nice color wiring diagram in my clymer manual I can use to figure things out as well. I have been reticent to remove the wrapping because I want the good insulation, I guess I should go buy some proper heat shrink down at oreillys or something and remove the sheathing on this so I can do this properly though.

If I'm reading your diagram correctly, yellow comes off of the regulator/rectifier (I did swap mine to a modern combo one) and the white wire is the headlight low beam? I'm trying to gain a better understanding of that mod. I know it tells the stator to give it full charge at all times and not just when the headlights are on, I'm just not sure how that's accomplished.
Yellow/White Mod - The original design bridges the two when you flip to hi beam. Totally over complicates it. See that yellow wire that comes out of the rectifier plug on the harness side? (red circle). It has a splice in the harness (black circle) that sends a run forward to the switch. Take that end, run that down to replace the white wire in that connection at the generator plug (blue circle). You'll have yellow>yellow, white> yellow #2 and pink>pink on one side, then just yellow and pink to go to the new rec/reg. white you just get rid of altogether in the harness.



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Okay awesome, thank you for breaking it down! I'll let you know if I have more questions about it once I get some hands on the bike this evening. Really appreciate you taking the time to walk me through all this EZpete.
 
That's not a factory ground anyway.
Just curious, why do you think this is the case? It looks like it's on the wiring diagram you shared (The green wire that goes to ground in the upper right hand side) and I did see the same ground on my other bike that's still bone stock as far as I know.
 
Also, where is the headlight grounds on this diagram? I know there are two one on each headlight housing bolt on the factory headlight set up. I'm just seeing grounds on the turn signals here.
 
Just curious, why do you think this is the case? It looks like it's on the wiring diagram you shared (The green wire that goes to ground in the upper right hand side) and I did see the same ground on my other bike that's still bone stock as far as I know.
That one is further back and went to the rectifier. It would be exiting the harness behind the battery, along with the wiring for the rectifier. Possible it’s the same wire that was separated out after some form of butchery was inflicted.

All of that front end relied on frame as the ground, so the ground wires are just stubs that attach to parts bolted to the frame. Part of why I’d take apart and reuse that aftermarket harness you’ve got is that it appears to have a couple of dual bullet connector grounds to use for all that stuff. Just connect the other end to the negative battery terminal and it’ll improve that - which makes LED conversions far easier.
 
Our sponsor Sparck Moto has one for the CB450.
I took a stab at making the PO's harness work again tonight. I was able to sucessfully solve the white/yellow wire circuit but in the process I got frustrated with the incorrectly colored wires. I decided I'll just order one of the Sparck Moto ones and have nice properly colored wires. It's so much easier diagnosing issues and making modifications when the wires are consistent with the wiring diagram and the colors are correct.

As far as the grounds are concerned I would love to ideally set everything up with the grounds all returning to the battery but to save time and effort I plan to just supplement the stock ones. That's how I set up the LED brake lights, I ran them a dedicated ground straight to the negative terminal on the battery.
 
I took a stab at making the PO's harness work again tonight. I was able to sucessfully solve the white/yellow wire circuit but in the process I got frustrated with the incorrectly colored wires. I decided I'll just order one of the Sparck Moto ones and have nice properly colored wires. It's so much easier diagnosing issues and making modifications when the wires are consistent with the wiring diagram and the colors are correct.

As far as the grounds are concerned I would love to ideally set everything up with the grounds all returning to the battery but to save time and effort I plan to just supplement the stock ones. That's how I set up the LED brake lights, I ran them a dedicated ground straight to the negative terminal on the battery.
Just run a backbone ground wire from the headlight bucket back to taillight. Branch it off to the battery negative and the rec/reg.
 
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