Danager4792
Veteran Member
If I remember correctly, the throttle plates between the 14h & 723A have different numbers stamped on them. Not sure what the numbers represent though. Maybe main jet size?
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1972 CB450 K5 Hot Mess
- Thread starter RobMan
- Start date
Maybe size of the little bypass flaps? no se... I may need to look, I know the linkage all is the same, I'm not sure I looked at the plates outside of them fitting the same in each carb. I guess stuff like "uh... this doesn't belong on this bike" isn't really covered under the FSM.
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Danager4792
Veteran Member
You’ll be able to verify, but I remember the 723A throttle plate stamped 145, and the other 14H carb said 130. Both of those are the main jet sizes for the carbs, is the only relation I can make.
That does sound like a very reasonable hypothesis - and something I'd totally have wrong! It would make sense though that the 723 would have an fractionally larger opening to mix properly with the richer jetting. Carbs are still off the bike from the engine rebuild, along with a bajillion spare parts in the CV carb box. If that is the case, at least it's the choke plate and not the throttle plate. Choke plate is easy to swap around.
Danager4792
Veteran Member
If I happen to have both throttle plates in my spare carb parts box, I’ll measure them with a digital caliper and compare.
RobMan
Veteran Member
Got the brass caps off the one I am salvaging bits from using both heat and pliers as gently as I could. Pressing around the cap helped although I ended up squeezing one a bit out of round but still usable and I think I will only need one. I checked the numbers on the throttle plates and all 3 of the 723A's have 100 stamped on them and 14H has 130.
Danager4792
Veteran Member
Those were the correct numbers… 130 and 100. Not 145. Would you be able to measure them and compare?
RobMan
Veteran Member
While it would have made sense to have 130 match the jet, looks like it’s 100 on the 723’s. Just checked all of mine and they’ve got 100’s in there.
I’m sure it’ll be readily apparent if it’s not a correct fit. Those things are so pee re cuse they’ve got to be facing the right direction.
I’m sure it’ll be readily apparent if it’s not a correct fit. Those things are so pee re cuse they’ve got to be facing the right direction.
Danager4792
Veteran Member
My apologies for my shady memory in regards to the numbers on the throttle plates. Just wanted to be sure you guys put in the correct throttle plates that were “intended” for the 723A’s.
RobMan
Veteran Member
With my memory I need all the help I can get. It would have been nice if they had stamped the main jet size on the throttle plate for a reference number.
RobMan
Veteran Member
I have a question, will soaking the carburetor bodies in Berrymans carb cleaner mess up the felt washers on the choke and throttle plate shafts? Also an interesting observation that on both 723A carburetors, one off the project and the other from the donor, the washer that goes between the spring and o ring on the air screw/idle mixture screw was missing. O ring not going to last long with out that washer.
wentwest
Veteran Member
The way I gave myself permission to go ahead and soak them anyway was that the washers are actually made out of felt, and I decided felt wouldn't be harmed by a detergent/solvent. The oil or grease that helped seal the felt would come out, but that I could replace,and I did.
As for the washer between the spring and o-ring, it's like a lot of other small parts that were sucked into the vacuum of ignorance brought to the bike by prior owners.
RobMan
Veteran Member
I had about talked myself in to just soaking the bodies and the worse that could happen is it would wash out some crud from the felt but uneasy that something "bad" could happen. I will do like you said and re-oil the felt after cleaning and it dries. I am lucky on the carb that came off the bike I am using that the insides are actually much cleaner than the outside. I think someone actually drained the fuel out of the bowl the last time it was put up back in the 80's. The outside is nasty as I think it was directly under a mouse family outhouse for all those years but it is cleaning up. Got the all the brass out by soaking in Kroil overnight and both carbs have 38 idle and 145 main jets. Ordered Honda gasket sets, needle and seats and screw sets A which has new idle speed and mixture screws and such from Partzilla. Next step a meticulous cleaning of the the jets, emulsion tubes and orifices. I purchased a set of guitar strings from Amazon as I had seen that is the tool of choice to clean these parts. I wish I was ordering them for a guitar but the only musical instrument I can play is the radio.
Here is an image of the Screw Set A I got off the internet.
String set, $9.00
RobMan
Veteran Member
Started soaking the left carb in Berrymans about 10 this morning and then cleaning up other bits and pieces. Pulled it out after 3 hours and got if pretty clean after a light scrub. I did notice that the felt washers (which were not in great shape before soaking) had not fared well and would need to be replaced. After thinking about trying to order a sheet of felt the right thickness I remembered I already had felt chair pad or glides and when I looked I had the right thickness. I got the caps off with a bit of struggle but didn't damage anything. Used the caps as a template and cut out two pads and used a standard paper punch to punch out the holes. A little off center seemed to work well when I assembled the choke plate and shaft back on the body.
Still have to final clean the jets and passages but overall looking good.
Still have to final clean the jets and passages but overall looking good.
RobMan
Veteran Member
Waiting on parts to be shipped from Partzilla, the Screw Set A are back order and I hope they don't have issues sourcing them. They are available from DSS and CMSNL but cost quite a bit more. As usual busy with honey do's and chores but did have time to do some more cleaning on the carbs. I still need to do another once over on them and I also want test the floats to make sure they haven't developed any leaks while sitting for uncounted years. I was thinking a weight tied to the floats and then put in a gas filled clear glass jar so the floats are completely submerged and let them set for a couple of days. Also a shout out to @Danager4792 who reached out with a some things to look out for and info on how to make a float gauge out of an old gift card. Anyway here is the results so far.
Danager4792
Veteran Member
Everything looks very clean - especially the carb bodies. Did you do anything to them, other than soak them?
If you have a hobby shop close by that sells model stuff they will normally have a bag of small metal washers that are the correct size. Use the original to compare to the ones they sell. I bought some locally years ago since PO’s don’t have the knowledge of what was in there originally.
Not using it will cause the spring to chew into the O ring, so it really needs to be in there to seal the circuit properly.
RobMan
Veteran Member
Just soaked in the carb cleaner and scrubbed a bit with a parts cleaning brush and some blue scotch brite pad. Luckily the carbs were actually quite clean on the inside.
RobMan
Veteran Member
Thanks foff TV the tip on the hobby shop and I may have to check into it if I have issues getting the screw sets. Keyster carb kits have them as well if I have to go that route.
Danager4792
Veteran Member
Also, if you need new float bowl gaskets. be sure you order genuine Honda. I tried 4into1's kits and the gasket never sealed properly. It was slightly too small and thin. Once I went genuine Honda, they fit perfectly. These also come with the small rubber o-ring bits.
Genuine Honda Carburetor Carb Repair Kits x2 NOS oem 65-74 cb450 cb 450 k0 | eBay
The carb kits will fit all models listed below.
www.ebay.com
RobMan
Veteran Member
I have the genuine Honda Gasket sets, Valve Sets, Float (Needles and Seats) on order from Partzilla as well as the Screw Set A which I need be cause the throttle stop screws and springs are very badly rusted from years of mouse urine.
Partzilla is showing they have everything but the screw sets which are back order. Hopefully they can fulfill the entire order.
RobMan
Veteran Member
Finished cleaning up the carbs and got the parts in I ordered. Unfortunately Partzilla was unable to fulfill the entire order with the Screw Set A being unavailable and I found I ordered the wrong needle and seat sets (Float Valve) as well. I have reached out to Partzilla and see if I can return the incorrect parts and order the right ones. Totally my bad so no complaints on that. I was able to order most of the individual bits from Northeast Vintage Cycle except for tiny washers that I needed for the idle mixture screws but @Danager4792 who had reached out some suggestions for a successful rebuild of my carbs had an extra set of the washers and sent them to me which is very appreciated. He had reminded me to use a light to check the throttle plates to make sure they were sealing properly in the bore which I did find one off and replace the plate from a donor carb and sealed much better. I was a bit nervous about removing the the throttle plate though as the screw heads were mangled at some point. I was finally able to remove one with a screwdriver but ended up having to drill out one of the screws which was a bit nerve racking. Got it out and used some screws from the donor carb. Used a center punch to re-flare the ends of the screws to lock them in. It may have been better to use Locktite but looks good to me.
Started putting the left carb together and have a question about the metal washer in the gasket set. I have looked over the Factory Parts manual but can't figure out where this sealing washer goes.
Started putting the left carb together and have a question about the metal washer in the gasket set. I have looked over the Factory Parts manual but can't figure out where this sealing washer goes.
RobMan
Veteran Member
After dinner and watching a movie with my wife I went back out to the garage and confirmed the only thing the metal washer will fit on is the float bowl drain plug but both 723As and the 14H all use a rubber O Ring there which is included in the kit. It is too small to fit on the silver plug that screws into the carb body itself. That plug uses a red fiber washer although the smaller of the 2 fiber washers in the kit is a little big but appears to seat OK. Of course the larger fiber washer is for the needle seat and fits there. The only thing I can think of is some other model carbs use the metal washer on the drain plug instead of an O Ring. I wish the seal kit came with a part number list of included parts.
RobMan
Veteran Member
Did a little more research at CMSNL and looks like the early CB450, K0 I suppose, used a metal sealing washer on the float bowl drain plug. Yes I get fixated on small puzzles and can find myself down the rabbit hole before I know it.
RobMan
Veteran Member
OK another rabbit hole. I ordered new new float valve sets (needle and seats) from Partzilla and after I got them opened one and saw that seat was marked 2.5 where the ones that came in the carbs are marked 2.0 which I assume is the opening in the valve seat. Checked part numbers and the parts manual calls for 16125-259-004 but what I got is part number 16011-375-004 which appears to be for the CB500T. I also looked up the part number out of the parts manual at DSS and it shows that it has been superceded by the part number I received.
My question is has anyone else noticed this and will it make any difference? The only difference I see is more fuel flow is available to the bowls at higher engine speeds which is probably a good thing.
On a side note I emailed Partzilla to ask about returning them and they have sent an RMA but did not note that it is a suitable substitute. To be fair in a conversation with their customer support on the phone he recommended that I place orders over the phone as they have better info than you get on the web site sometimes especially on older models.
My question is has anyone else noticed this and will it make any difference? The only difference I see is more fuel flow is available to the bowls at higher engine speeds which is probably a good thing.
On a side note I emailed Partzilla to ask about returning them and they have sent an RMA but did not note that it is a suitable substitute. To be fair in a conversation with their customer support on the phone he recommended that I place orders over the phone as they have better info than you get on the web site sometimes especially on older models.
LOL, everything we deal with is old, like most of us.
Higher fuel flow rate which isn't a bad thing, especially at higher. With a good float and float needle there will be no effects of the higher rate.
RobMan
Veteran Member
Got the carbs put together and tested the slides with the "blow test" method suggested by @Danager4792 using a straw and blowing in to one of the ports on the choke side to cause the piston to rise and then fall when pressure is released. They both are working freely. I also used the gift card template he sent an image of to make a float gauge and set the floats. Set the idle mixture screws at 1.5 turns out but will need to sync them when I finally get to a point I can install on the engine and see if it will run which is still quite a way down the line.
Probably going to take a short break from starting on next steps as I need to winterize all my outdoor equipment. I usually do all the oil changes and such at this time of the year so when I start dragging stuff out next spring it is ready to go. Like everything else what used to take a day now takes a week or two.
Probably going to take a short break from starting on next steps as I need to winterize all my outdoor equipment. I usually do all the oil changes and such at this time of the year so when I start dragging stuff out next spring it is ready to go. Like everything else what used to take a day now takes a week or two.
Hopefully you already used up the balance on that gift card, not sure they'd redeem it in the present condition.
RobMan
Veteran Member
Wanted to do a small update on progress but haven't done a lot since finishing the carburetors. Next major step is to strip the chassis down to the frame and I was going to pull the rear wheel but waiting on a 26 MM deep impact socket as the nut is froze up tight even after soaking with PB Blaster and Kroil for several days. I assumed I could get it off with heating with a propane torch, a large crescent and tapping the handle with a hammer but no joy. Hopefully once I get the socket my impact gun will do the trick. While waiting I removed the battery box which is a rusted mess. Removed the starter solenoid, rectifier and the blinker and scraped as much rust off as I could. Got the small bits in jar of Evaporust and the soaking the box itself in a bucket of vinegar. I need to bench test the solenoid and other electrics just to see if anything can be salvaged.
Clean that rectifier up and use it as a paperweight, and remove the regulator from the bottom of the battery box too. Get a Sparck Moto rec/reg combo unit if you haven't already, it's the best way to go (and the least expensive way to get there).
12V Single Phase Regulator/Rectifier - Sparck Moto
Sparck Moto - Modern Gear for your Vintage Ride
www.sparckmoto.com
RobMan
Veteran Member
For that price I am sure I will go that route. The main harness is pretty rough and I had already decided to buy a new harness from them so I wouldn't have to chase gremlins.Clean that rectifier up and use it as a paperweight, and remove the regulator from the bottom of the battery box too. Get a Sparck Moto rec/reg combo unit if you haven't already, it's the best way to go (and the least expensive way to get there).
12V Single Phase Regulator/Rectifier - Sparck Moto
Sparck Moto - Modern Gear for your Vintage Ride
RobMan
Veteran Member
VICTORY! A small triumph, got the rear axle nut off and I am giving credit to the harbor freight BAUER 20V Impact Wrench my wife got me for Christmas several years ago. Yes I guess this is an endorsement and I sure wish I had had that tool so many times in the past. OK I am sure the PB Blaster and Kroil helped as well.
RobMan
Veteran Member
Got the rear wheel off and started trying to get the backing plate off the hub. I can get the plate to rotate by tapping the arm with a plastic hammer and can get it to shift away from the drum about a 1/4 inch. Obviously the shoes are rusted in place so looking for suggestions on getting it loosened up without damaging the hub or backing plate. The spokes and wheel in very rough shape so definitely new spokes and very probably new wheels as well.
I figure the areas marked are where it is rusted up so looking for ways to get Kroil or PB Blaster to those areas without having to soak the whole hub.
I figure the areas marked are where it is rusted up so looking for ways to get Kroil or PB Blaster to those areas without having to soak the whole hub.
That's a tough one Rob, I didn't recall the bike being quite that bad in some areas. The splined shaft for the cam would be the easy one, just take the arm off it and dribble the Kroil down the shaft. Can you move the arm at all right now? The look of the zip tie through it makes me wonder if it's stuck in a position where the shoes are expanded a bit.
RobMan
Veteran Member
Thanks Tom the arm is locked tight and I did dribble Kroil along the opening but got the plate out after thinking about it a little longer took a 10 inch length of 1/2 inch PEX pipe and used as a drift along the edge of the backing plate and after a bit it started coming out. Although locked up the backing plate and shoes not really in that bad of shape although I am sure it will present new challenges. I like PEX over PVC as it is a bit softer so not as likely to damage what I am hammering on.
Glad you got it out. You'll want to replace the shoes since it's obvious they've been exposed to a lot of dampness. Shoes exposed to high levels of dampness will start to corrode the aluminum frames and cause the linings to delaminate.
RobMan
Veteran Member
Yep good brakes are just as important or even more than a good running engine. After a couple of close calls in my younger days I make sure the brakes on anything I drive is working properly.
wentwest
Veteran Member
I wrote the next paragraph before it dawned on me that you might have gotten them fully apart. If you did, congratulations! If not, here's my thought.
The inside of the brake drum is probably rusty and dragging on the brake shoes. There's really nothing else I can think of holding the backing plate on. If it's all clean and correct it really just falls off, usually on my foot. I'd try to rotate the plate, many rig up a breaker bar with a socket that fits into the axle hole and put a strong, longer bolt through the hole where the stopper arm bolts up. Then you can get good leverage to rotate the backing plate while maybe someone else stands on the tire while it's laying flat on the floor.
The inside of the brake drum is probably rusty and dragging on the brake shoes. There's really nothing else I can think of holding the backing plate on. If it's all clean and correct it really just falls off, usually on my foot. I'd try to rotate the plate, many rig up a breaker bar with a socket that fits into the axle hole and put a strong, longer bolt through the hole where the stopper arm bolts up. Then you can get good leverage to rotate the backing plate while maybe someone else stands on the tire while it's laying flat on the floor.
RobMan
Veteran Member
Thank you for the suggestion but thankfully I was able to get it apart relatively easily. I just need to needed to step back and try another approach. I really didn't want to break anything.
RobMan
Veteran Member
Hey Tom just wanted to post a cautionary picture of the hazards of using old brake shoes no matter how good they look. The brake lining separated from the shoe with just a tap of a plastic mallet on the shoe itself when I was trying to get it to rotate on the pivot.
On a side note it is a beautiful day here so took the S90 out for a spin even though she was embarrassed to be seen without her gaiters on. Took the picture by the old Glencoe textile mill on the Haw River. Some of the water wheel gears in the background.
Yep, not at all surprised after seeing how crusty that brake panel looked once you got it out of the drum. Life would get really ugly in a hurry with shoes in that condition. I have a picture much like that.
RobMan
Veteran Member
Removed the front forks and was a bit disappointed when the found the upper fork bridge broken the same way that @efranzen had posted about on his SL350 which he ended up having welded. Although mine is a CB450 I am facing the similar options for the most part with everything from a unopened NOS one on ebay where they are asking $895.00 and a used one for $149.95. I did find that CMC sells a a reproduction for $150.00 that includes hardware and damper set and at that price should be free shipping. Has anyone used the fork bridge they sell and if so how did it work out.
Here is a pic of mine.
Honda CB450 / CL450 Scrambler Upper Triple Tree | Common Motor Collective
www.common-motor.com
Here is a pic of mine.
Not sure about the 450, but there are a few here who've bought CMC's top bridge for their 350s and were happy with it, I think @ballbearian and @stl360+450 both have.
Danager4792
Veteran Member
I have the CMC top bridge on my bike (CL450). No complaints. Comes with new handlebar dampers too. Supposedly it’s made with higher quality metal, so less likely of cracking again.
Edited to add photo
Edited to add photo
RobMan
Veteran Member
Thanks for the feedback, frankly it sounds like a no brainer to me but glad to hear someone has used it with good results.
RobMan
Veteran Member
Question though, did you use the "D" washers on the new one from CMC? I was reading they are very important on the stock bridge but CMC dose not supply them with the hardware so wondering if they are not needed.