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1972 CB450 K5 Hot Mess

boddy said:
Coming along nicely!
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Thanks, I am pleased with it so far. Of course the test will be starting it up the first time which is a ways away. Really haven't touched the chassis or running gear yet so a long way to go but winter is coming and my wife will have fewer chores for me to do. Maybe next spring. :unsure:
 
I never understood why people paint the cylinders and head, and if painting, why black ? I know the English motorcycle factory's painted their cylinders black, but that was for a whole other reason. For water cooled engines it doesn't matter, but an air cooled engine ? Every layer between air and aluminum is an isolator, no matter if it's black or silver. The discussion if black is better than silver is a physics related item, but I don't want to go too deep into that matter.
 
jensen said:
I never understood why people paint the cylinders and head, and if painting, why black ? I know the English motorcycle factory's painted their cylinders black, but that was for a whole other reason. For water cooled engines it doesn't matter, but an air cooled engine ? Every layer between air and aluminum is an isolator, no matter if it's black or silver. The discussion if black is better than silver is a physics related item, but I don't want to go too deep into that matter.
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Personal preference, I just like the aesthetics. :)
 
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In between chores and actually doing some work on the engine I took a look at the carbs and after cleaning away some crud saw that they were different part numbers left 723A (Choke handle side) and right 14H. I knew I had just seen those number mentioned recently, see @EzPete's thread https://www.vintagehondatwins.com/forums/index.php?threads/723a-parts-compatibility.11685/ where @Danager4792 said he found the same mismatch. I also found a thread on the site that will not be mentioned from 2011 where the same issue is brought up. I do have another 723A carb that came with the donor engine but it is a left hand as well. Looks like carb mismatch is fairly common. I will have to clean them up and see if the choke shaft can be swapped from the 14H to the 723A so I can have a matched set. Disregard that last sentence, forgot Idle speed and mixture screws would be on the wrong side as well as the cable linkage.
 
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RobMan said:
In between chores and actually doing some work on the engine I took a look at the carbs and after cleaning away some crud saw that they were different part numbers left 723A (Choke handle side) and right 14H. I knew I had just seen those number mentioned recently, see @EzPete's thread https://www.vintagehondatwins.com/forums/index.php?threads/723a-parts-compatibility.11685/ where @Danager4792 said he found the same mismatch. I also found a thread on the site that will not be mentioned from 2011 where the same issue is brought up. I do have another 723A carb that came with the donor engine but it is a left hand as well. Looks like carb mismatch is fairly common. I will have to clean them up and see if the choke shaft can be swapped from the 14H to the 723A so I can have a matched set. Disregard that last sentence, forgot Idle speed and mixture screws would be on the wrong side as well as the cable linkage.
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Hey, I think you have my mismatched carbs, and I have yours 🤣

Have you decided which carb model you will get the matching one for? I believe yours runs a 723A set. They changed them starting with 1972 I think. The differences are the fuel mixture screw, main jet, and the throttle plate has a different number on it. One had a plate stamped “130” and the other “100”, can’t remember which were which and what that meant.

There’s a little bit more to the story of mine which I didn’t want to elaborate on too much previously. My 723A carb got ruined when I screwed the wrong mixture screw into the body. Then, when I bought a 14H carb on eBay, it had been converted to be the opposite side carb. Throttle linkage was welded onto the opposite side, shafts were reversed, crazy stuff. I tried swapping the shafts over from my ruined 723A carb. It was a success but the carb never acted right. I should have just returned it.

Ended up finding a decent condition 14H carb and it’s been good ever since. I tried to find one on eBay where the throttle plate screws looked untouched. That was evidence for me that it was a good carb before it sat and was pulled then sold.

After getting in contact with the original owners son for my bike, he couldn’t believe there were mismatched carbs. He sold the bike cause he couldn’t get it to idle right. He remembered in 1982 when his buddy dropped off a ‘72 Cl450 spare parts engine with carbs attached to it. He had no idea they were different than his and got them mixed up.
 
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Thanks for sharing the rest of the story as Paul Harvey would say. Wish I had known what I had when you were looking for a 14H but perhaps someone else will run into this issue. They look identical to the eye so the mix up must have been very common and easy to do unless you knew to take a look at the model numbers. I will probably try to find a right 723A to make a set seeing as I have two left hand 723A which would give me some extra brass and such. I have looked at the Mikuni carb kits I have seen on line but they are pretty pricey and I would need to get some really good feedback that they work as advertised before investing. Honestly most of my motorcycle carb experience was with Amal carbs when I had a BSA and some friends had a Triumph and a Norton and that was a long time ago. As I remember they were super simple, just remember to give em a tickle when it was cold. :)
 
It seems like there should be a way to start a swap list for carbs. I bet lots of us have a collection of carbs.
 
wentwest said:
It seems like there should be a way to start a swap list for carbs. I bet lots of us have a collection of carbs.
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I know what you mean about a list but I can also see it becoming outdated really quickly and a pain for the admins to try to manage. There is the Parts Wanted thread where we could list what we need and what we have to trade which would keep it more one on one. I would love to trade my right hand 14H for a right hand 723A and failing a trade I should see if anyone has a 723A for sale before hitting ebay.
 
RobMan said:
I know what you mean about a list but I can also see it becoming outdated really quickly and a pain for the admins to try to manage. There is the Parts Wanted thread where we could list what we need and what we have to trade which would keep it more one on one. I would love to trade my right hand 14H for a right hand 723A and failing a trade I should see if anyone has a 723A for sale before hitting ebay.
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I'll check my box. I know I ordered the wrong side twice - just cant remember if it was right or left. I also have a couple that the emulsifier tube was stripped on and I just need to run the 7mm tap through - those could be 14H's though. It was one of those situations where you put two carbs in a box and suddenly there's 6 mismatched ones.
 
EzPete said:
I'll check my box. I know I ordered the wrong side twice - just cant remember if it was right or left. I also have a couple that the emulsifier tube was stripped on and I just need to run the 7mm tap through - those could be 14H's though. It was one of those situations where you put two carbs in a box and suddenly there's 6 mismatched ones.
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I know what you mean about things getting mixed and lost. I am not the most organized person naturally so I have to work pretty hard to keep things organized but I swear there are gremlins that delight in working against me. I really appreciate your taking a look at your carbs when you have a chance.
 
Feel like I made another milestone and installed the cylinder head. Applied a light coat of Hondabond 4 top and bottom of the head gasket where @ancientdad had suggested. I used a Q-Tip as an applicator to be sure not to over do. Got the flat seals through the gasket and on the knock pins and threaded the cam chain through the head. Removed the wood block (and the blue PEX pipe which was holding the chain out of the Hondabond) and eased the head down with no issues. Gave it a few light taps with a plastic mallet for love and then torqued to specs. To my eye it looks good. Next step is to make sure I have it timed properly and rivet the cam chain.

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RobMan said:
I know what you mean about things getting mixed and lost. I am not the most organized person naturally so I have to work pretty hard to keep things organized but I swear there are gremlins that delight in working against me. I really appreciate your taking a look at your carbs when you have a chance.
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I'll look through my bin of carbs, too. I have about 6, some crap for parts, some sort of whole, but all for CB450's.
 
Getting ready to to try to get the cam chain connected and wanted to post some pics to make sure I have all the timing marks correct.

Got the LT mark lined up no problem after I thought to use my handy penny from the bottom of the crank and clutch basket gears to keep it from falling off TDC.

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The exhaust cam also looks pretty obvious although I have to admit a casting mark I had me faked out at first but found the dot after I rotated the cam a bit.


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The intake cam is not as obvious so appreciated some confirmation on it. Its crazy there appears to be several ways the cams were marked.

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The question is, are you holding the intake cam in position in the last pic? Because when the intake cam timing mark is correctly in position, the cam is just starting to open the right intake valve and it will spring back unless held in place. The mark does look correct. It's odd that some have dots while most of them have the typical marks like on your intake cam. The ghost marks on some cams can certainly mislead sometimes, but your intake cam mark looks legit.
 
Thanks for confirmation, it settles the butterflies you get later when you start second guessing yourself. There is pressure on the intake cam and you can see it is still a bit off. I will be sure to hold it in place when I put the chain together. I can see how it could confuse people as the casting mark is much more visible and I even looked at the other set of cams I have and one of them is even more poorly marked. The chisel mark looks more like a small ding or something accidental.
 
The small distance that the mark is below the index on the cam bearing is well within tolerance of accurate timing, as the distance of one tooth off is a lot more visibly.

Once you get the master link staked, turn the engine over very gently and of course, if you run into any resistance at all, don't force past it. Be sure the tensioner assembly is bolted on and adjusted before doing any rotation to be sure the timing will not jump a tooth.
 
OK stepped away again from trying to get the cam chain to line up and slip in to the gears so I can start the master link. Seems like it always about a 1/2 link off with a bit too much slack on the chain. I have tried connecting on the the intake side which is what the FSM suggests and I then tried from the exhaust side. I have tried repositioning the cams a bit to get the settle into position but no luck so far. Happy to accept advice, recommendation on a thread or a good video that might help.
 
I found it best to join the chain on the intake side. With the rotor on the LT mark and the exhaust cam lined up, I ensured there was no slack on the exhaust side by putting tension on the exhaust side of the chain before putting the chain over the exhaust cam sprocket. you can then feed the remainder of the chain to the intake side. If you are off 1/2 tooth on the intake side, I would position the intake cam such that you can get the ends to join then check the alignment marks.
 
boddy said:
I found it best to join the chain on the intake side. With the rotor on the LT mark and the exhaust cam lined up, I ensured there was no slack on the exhaust side by putting tension on the exhaust side of the chain before putting the chain over the exhaust cam sprocket. you can then feed the remainder of the chain to the intake side. If you are off 1/2 tooth on the intake side, I would position the intake cam such that you can get the ends to join then check the alignment marks.
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Thanks, I will give that a try. It makes me very nervous to keep messing with it and possibly drop the chain down in the case or something.
 
RobMan said:
Thanks, I will give that a try. It makes me very nervous to keep messing with it and possibly drop the chain down in the case or something.
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Though I have connected the chain on the exhaust side before (but only when doing some work with the engine still in the frame), the fact that the intake cam won't sit still on the mark while the exhaust cam will (because it's in the middle of opening a valve) makes aligning the mark on the intake cam during assembly much easier than trying to hold the intake cam in position while feeding the chain across to the exhaust side. The exhaust side is a big part of getting the intake side to align with enough chain slack to put the master link in, and Boddy is right about needing zero slack on the exhaust side for that reason. When you're using a new cam chain it's always more difficult to get the two ends together and hold them in place on the intake cam while slipping the link in. You don't have the tensioner assembly on the cylinders already, do you?
 
ancientdad said:
Though I have connected the chain on the exhaust side before (but only when doing some work with the engine still in the frame), the fact that the intake cam won't sit still on the mark while the exhaust cam will (because it's in the middle of opening a valve) makes aligning the mark on the intake cam during assembly much easier than trying to hold the intake cam in position while feeding the chain across to the exhaust side. The exhaust side is a big part of getting the intake side to align with enough chain slack to put the master link in, and Boddy is right about needing zero slack on the exhaust side for that reason. When you're using a new cam chain it's always more difficult to get the two ends together and hold them in place on the intake cam while slipping the link in. You don't have the tensioner assembly on the cylinders already, do you?
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I know I am having an issue with getting the slack out of the chain on the exhaust side when trying to connect on the intake side. I have tried moving the exhaust cam back a bit so I can grab a link and then move the exhaust cam back on mark and get the slack out but no joy yet. I do not have the tensioner installed and I will just have to be very careful and play with it. Patience.
 
RobMan said:
I will just have to be very careful and play with it. Patience.
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It can feel daunting for the first-timer, no doubt. As you've done all along, take your time and yes, be patient. Hopefully you ordered a couple extra master links to work with, you might end up using a second one. Though it really isn't overly tricky, you can see why this top end intimidates some, it's just different. Probably why I've always gravitated to the 450 engine because I'm that way too.
 
I was running into the same dang problem when I did mine the last 2 times. Here's where mine was snagging:

Cam Chain.jpg
There was just enough slack between the bottom of the crankshaft tooth and that guide gear at C to kind of half fold the chain at C. IT would feel tight, but wasn't quite seated right - it was engaged at the 8 o'clock position and with the angle of everything you couldn't quite get the right pull to bring it around and take that slack out.

I tied braided fishing line to both ends of the chain and keeping tension on the intake side (keeping the chain engaged on the crank gear) quickly flipped the line on the exhaust side like a swim bait and got that little bit of extra slack free by getting that gear at C to shift where the chain would engage past the 9 o'clock position. You can kind of see in the drawing where the first link that is fully engaged on the C gear is actually above that line.

Hope that makes sense.
 
EzPete said:
I was running into the same dang problem when I did mine the last 2 times. Here's where mine was snagging:

View attachment 37127
There was just enough slack between the bottom of the crankshaft tooth and that guide gear at C to kind of half fold the chain at C. IT would feel tight, but wasn't quite seated right - it was engaged at the 8 o'clock position and with the angle of everything you couldn't quite get the right pull to bring it around and take that slack out.

I tied braided fishing line to both ends of the chain and keeping tension on the intake side (keeping the chain engaged on the crank gear) quickly flipped the line on the exhaust side like a swim bait and got that little bit of extra slack free by getting that gear at C to shift where the chain would engage past the 9 o'clock position. You can kind of see in the drawing where the first link that is fully engaged on the C gear is actually above that line.

Hope that makes sense.
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I do see what your saying after reading it a couple of times and looking at the diagram and I can see it hanging there. The funny thing is I have done this before when I did a top end rebuild and exhaust cam replacement on my CB450 I had when I was in the Air Force back in the 70's. I really can't remember a lot of details other than I was using a Clymer or a Hanes manual and I was working in the parking lot outside the barracks and covered the bike with a tarp. The hazy recollection is probably due to beer and possibly other things things. I do know I got it running successfully and made at least 2 or 3 trips from my base in the Mojave desert to the mountains and to the basin once all the way to San Diego. I think I sold the bike for about $200.00 before going overseas.
 
Found this on the forum, it might help you get the slack out of the exhaust side of the chain.

How to get your cam timing marks dead on. With help from Steve

How to get your cam timing marks dead on. With help from 66Sprint. Over the last month or so, I’ve been taking a whipping on a ‘72 CB450. Luckily, I found this forum & Steve aka 66Sprint. I tried an EK timing chain and a Honda timing chain. I was having a heck of a time getting the marks to...
www.vintagehondatwins.com www.vintagehondatwins.com
 
Thank you I had actually found that a little while ago using a Google search and added it to my watch list. It goes along with what I had figured out that I was going to need to move the cam or crank a bit to get the chain on and then move it back to the appropriate timing mark to take out the slack on the exhaust side. Earlier today I actually got the chain to a point where I could have slipped the master link in place if I only had an extra pair of arms. When got your cam chain installed were all the marks exactly lined up or were any of them off slightly?
 
RobMan said:
Thank you I had actually found that a little while ago using a Google search and added it to my watch list. It goes along with what I had figured out that I was going to need to move the cam or crank a bit to get the chain on and then move it back to the appropriate timing mark to take out the slack on the exhaust side. Earlier today I actually got the chain to a point where I could have slipped the master link in place if I only had an extra pair of arms. When got your cam chain installed were all the marks exactly lined up or were any of them off slightly?
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My exhaust lands just off a whisker (mark slightly below) when the intake is lined up up exactly. Last time, I did it with a friend of mine and that second set of hands made it 10x easier to keep the exhaust in place while I lined up the intake and stretched the chain through.

Definitely a far cry better than when I dropped the chain the first time
 
EzPete said:
My exhaust lands just off a whisker (mark slightly below) when the intake is lined up up exactly. Last time, I did it with a friend of mine and that second set of hands made it 10x easier to keep the exhaust in place while I lined up the intake and stretched the chain through.

Definitely a far cry better than when I dropped the chain the first time
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Friends are good. Dropping the chain or the master link in the case would be bad.
 
RobMan said:
Thank you I had actually found that a little while ago using a Google search and added it to my watch list. It goes along with what I had figured out that I was going to need to move the cam or crank a bit to get the chain on and then move it back to the appropriate timing mark to take out the slack on the exhaust side. Earlier today I actually got the chain to a point where I could have slipped the master link in place if I only had an extra pair of arms. When got your cam chain installed were all the marks exactly lined up or were any of them off slightly?
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As I recall the marks were pretty much aligned, not off by more than the width of the the alignment mark. I did have too much chain on the exhaust side and just barely enough on the intake side to insert the master link. Once the link was inserted I rotated the crank a bit to bring the master link to an area where I could brace the master link in order to peen over the pins. After I peened the master link I rotated the crank slowly through 360 degrees to ensure the marks lined up.
 
RobMan said:
Dropping the chain or the master link in the case would be bad.
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I've dropped the chain a few times and the more you do it, the better you get at retrieving it. Last time, while doing it in the frame during my early oil flow issues, I used one of those flexible "grabbers" along with my HF inspection camera.

grabber.jpg

Tricky, but it worked. But I was also fortunate that the chain piled up on the guide rollers and didn't fall all the way to the bottom end.

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And I thought I'd mention this too, because when you're doing it by yourself and need to keep the portion of the chain coming from the front on the upper half of the intake cam sprocket, a big screwdriver or similar can be wedged into the head above the chain to hold it in place with the timing mark aligned. You can just see the handle of the screwdriver zip-tied around the frame to hold it in place.

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Got the master link in place this morning and I think the marks are as good as they are going to get. Let me know what you think. Just got the master link in but haven't staked it yet and I have rocked the crank a bit just to make sure it wasn't locked up.

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ancientdad said:
I've dropped the chain a few times and the more you do it, the better you get at retrieving it. Last time, while doing it in the frame during my early oil flow issues, I used one of those flexible "grabbers" along with my HF inspection camera.

View attachment 37173

Tricky, but it worked. But I was also fortunate that the chain piled up on the guide rollers and didn't fall all the way to the bottom end.

View attachment 37167

View attachment 37168

And I thought I'd mention this too, because when you're doing it by yourself and need to keep the portion of the chain coming from the front on the upper half of the intake cam sprocket, a big screwdriver or similar can be wedged into the head above the chain to hold it in place with the timing mark aligned. You can just see the handle of the screwdriver zip-tied around the frame to hold it in place.

View attachment 37169
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Thanks I do have the claw and a couple of different magnets but glad I don't have to go fish. I used a piece of heater hose to wedge the top chain in place.
 
RobMan said:
I used a piece of heater hose to wedge the top chain in place.
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I was just looking at that, good thinking. I'd say you have it as close as it can be, the exhaust cam is a tiny bit "late" but it is what it is and that's how these can go. Before you stake the link, is there any free movement of the crankshaft or since it's a new chain, is it reasonably tight? If there's little movement then for sure it's good.
 
The chain on the exhaust side is pretty tight, I can deflect it a small amount but certainly not enough for a missed link. There is some play if I push the chain through the tensioner opening but not too much. I can rock the crank a bit and it moves both cams as it moves. Next step is to stake the cam and then install the tensioner and set it. Test will be to see if I rotate the the engine a few times and make sure everything lines back up. Fingers crossed.
 
RobMan said:
The chain on the exhaust side is pretty tight, I can deflect it a small amount but certainly not enough for a missed link. There is some play if I push the chain through the tensioner opening but not too much. I can rock the crank a bit and it moves both cams as it moves. Next step is to stake the cam and then install the tensioner and set it. Test will be to see if I rotate the the engine a few times and make sure everything lines back up. Fingers crossed.
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From the look of everything, you should be fine.
 
OK staked the master link. Tried at first using a center punch with a nut and bolt wedged on the back side of the master link like @boddy but wasn't working out so regrouped and got out the cheapie chain breaker kit and put a point on one of the press pins and used it to flare the tip. That seemed to work out better but not sure if I need to work it a bit more. Here is a picture of the pins and there is about 20 thousandths between the link and the side plate. Put the tensioner on and set it and I have cranked the engine about 4 complete rotation with no binding and the timing marks line back at the LT mark.


IMG_4652.JPG
 
Looks good. As long as the side plate isn't loose between the shoulder on the link pins and the staked ends of the pins, you're good. There's really little side thrust involved, but the mushroomed ends just need to make the side plate tight at the link pin shoulders without restricting the flexibility of the link.
 
When I did this job I used a bunch of rare earth magnets I bought at the source (Harbor Freight), for a few dollars. They are about the size of buttons and they held the chain tight on the exhaust cam sprockets. @jensen wrote that I was running the risk of inducing magnetism into the chain and the sprocket and they would attract steel filings. By that time I was done. I suspect he's right, so maybe I shouldn't be writing this, but it worked really well!
 
Working on setting the valves and have a question about clearence. The FSM calls for 0.03 mm or 0.0012 inch. I believe have seen somewhere that this is to tight and should be a bit looser.Just wondering what more experienced folks say?
 
Running in on 0.05, and when ran in, go to 0.03 mm, otherwise (when setting the valves to 0.03 immediately after rebuild) check valve clearance after 50 mls (and re-torque the head as well) and then every 250 miles-sh after rebuild until you reach 750 - 1000 mls. I use the second method, because when re-torque the head, you have to get there anyway.
 
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