Topic: 71' CB500 Carb question

[chascp84]

Hey guys I'm new to the forum. There is so much helpful information on this site, I thought I would reach out to the Honda experts.  This is my first bike rebuild, I have always worked on cars but never a motorcycle so I figured I start somewhere.  I am rebuilding my carbs on a 71' CB500 and ran into some issues.  The first issue is, how to I get the stay plate off the slide?  I want to sand blast it to clean it up.  My other concern is, when i pulled the bowls off, i did not see leaf springs.  These carbs should have leaf springs correct?  Where can I get a set so I can finish the rebuild?  This is my little winter project after having to sell my jeep wranglers, so any help would be awesome.  Thanks

[brooze72]

Hi chascp84 & welcome

You will find some excellent carb info on the main SOHC4 website, look under the "Tech" tab (& there may be more under the "500" tab too).  They wil lead you to some good stuff.  I also saw very nice pictoral rebuild of carbs on a 500 that was featured early this year in the Motorcycle Classics magazine. I think it is still in the archives on their website, if you can't find it I could send you a copy.  Good luck with the project & enjoy!

[Frostyboy]

Now not that I know for sure, but maybe you have the PD style carbs here. I understand they have screw in mains. The leaf springs you speak of are fitted to the other style carb which have press in main jets. The leaf spring holds them in place once the bowls are fitted.

[chascp84]

Thanks for the replies guys.  I went to a local bike shop and found the leaf springs.  After shooting the @#$% with the owner for a bit, he handed me a flashlight and said go upstairs and I will see you in a few hours.  I walk upstairs, and there is pandoras box of bike parts!  Everything from engines to speedo clusters.  He had a whole section just for carbs that were stuffed in milk crates.  Luckily the first carb I honed in on looked to be the same as the one on my bike.  I brought it down stairs took the springs out and bought them for 20 bucks.  After taking them home, i had an issue with the bowls not fitting on the carbs with the springs installed.  Frostyboy are you saying that my carbs may not need the springs?  Not really ure how to determine if they are PD carbs.  They are Keihin and have a stamp in the cast that reads 627B.  Attached are pics of the carb, arial view and the gap left after the springs installed.  Any insite would be awesome!  Thanks!

[domer]

what you need also holds your main jet in... it kinda clips around the jet and uses pressure from the bowl to hold it in... cant find a pic at the moment but heres a parts fiche, it can be seen in the lower left corner of the pic...

http://www.bikebandit.com/houseofmotorcycles/1973-honda-motorcycle-cb500k2/o/m9228#sch398717

[dave500]

you have the type one carbs,not pd,you need the springs,the bowl will stop a little from closing untill you push a little,this spring hooks around the main jet and the tangs touch in the bottom of the bowl holding the jet in place.

[chascp84]

what you need also holds your main jet in... it kinda clips around the jet and uses pressure from the bowl to hold it in... cant find a pic at the moment but heres a parts fiche, it can be seen in the lower left corner of the pic...

Domer, yes the part you are talking about is the leaf spring that was missing when I tore the carb apart.

you have the type one carbs,not pd,you need the springs,the bowl will stop a little from closing untill you push a little,this spring hooks around the main jet and the tangs touch in the bottom of the bowl holding the jet in place.

dave500, thanks for letting me know what carbs I have.  That old saying is true "you learn something new everyday."  I was just confused because when i took the springs off the other carb, there was no pressure to the bowls.  Anyways thanks for the help guys I will try to get a topic going about the whole build soon.

[dave500]

did you buy the entire carb rack for twenty bucks?if those are rusty they might have lost some tension.i was missing one from a set once and considered trying to make one from an old clock mainspring or something.

[chascp84]

No just the springs for twenty, i wish he sold the whole rack for 20 lol.  They are not too bad since the picture i clean them up a bit with carb cleaner and some elbow grease.  I took that picture when i was at work trying to get more info before i put the carbs back together.  I also found out that the stay plate is attached to the slide and has some type of rivot were they can not be separated.  I was a little disappointed with that because i wanted to paint it but oh well.  Next thing, I need to find a gasket kit for this bike.  I had the shop look to see if Vesrah still makes it, but he said no.  How different is the 550 kit from the 500?   

[dave500]

you can buy keyster brand,the bowl o ring will have to be held in place with a little drop of instant super glue in a couple of the corners,david silvers has these kits,someone here will know where to get them closer to you i think.

[TwoTired]

These kits are what I got through Honda.

[chascp84]

Thanks guys, but i was talking about the engine gasket kit.  I probably should have mention that in the post.  I found a new head gasket, but i need the whole thing kit.  Cover gaskets, head gasket, valve seals, etc.  I was able to reuse my bowl gaskets and i purchased the jet o-rings already.  I came across a engine gasket set on ebay but it doesn't look like it has the valve seals.

[brooze72]

FYI Check in with your local Honda shop.  Amazingly lots of that stuff is still available & they know exactly what you need too!  I was able to get all my gaskets & they weren't a stupid price either.