Topic: Compatible Parts for 1979 CB650 Carbs

[adr3naline]

Hey! I've got my 1979 CB650 that I'm fixing up. The first time I put gas in it, I had tons of gas pouring out of the overflows and even out of the intakes! So, I opened them up, and they were pretty filthy, so I cleaned them. The floats didn't seem to be locked up at all, and moved freely. I assumed it would be fine... but then I tried it again, and it still was dumping gas.

I'm going to pull the carbs again to inspect the parts more carefully. I'm going to test the floats in some water to make sure they're good, and the needle valves all seemed good.

So, I have 2 questions as I proceed. 

1.  Are there other bikes that have the same carburetors so I can do searches for parts if I need them? (like for boots specifically)
2.  Is it better to leave the boots on the carbs or the engine? It was pretty rough getting them back on this last time, and I finally got them on by attaching them to the carbs then pushing them onto the engine... Is there a trick to getting them on easier?

Thank you!!

[curemode2002]

1. Not sure on other bikes part of the question but http://www.siriusconinc.com has a ton of parts for the carbs and they are the best price I have found. Be careful though your 79 uses the same PD style carbs as my 80 but from 81 on they used the CV carbs and most of those parts are not interchangeable. Also get a couple of carb bowl gasket sets from them having more than one set makes it way easier to clean and service the carbs while still on the bike.

2. I always put them on the head then press the carbs on but it really doesn't seem to matter much. If you heat them a little with like a blow dryer they are much easier to work with. Also there are a few posts on the forum that are pretty good. One guy soaks them in a simple green solution to get them pliable. But for me the blow dryer is the easiest as my wife is a beautician so there is always a spare one I can borrow/appropriate for the garage.

[davesee]

yup, the '80 shares the same carbs.

i leave the boots on the head. i use a compression strap to hold back the airbox, then i wedge the carbs into position, and use another compression strap to ratchet them into the boots and home. if you're terrible at cleaning carbs, you'll get really good at taking them on and off. ask how i know.

[Hush]

If gas is pouring out I would say your needle valves are shot, it's not a bad thing to replace them anyway when you don't know their history, they are cheap as anyway.
If you cannot get new carb gaskets then just buy a tube of gasket maker and after cleaning up your old ones coat them with the gasket maker and good to go.
I always leave the carb isolators on the head, I use a trailer ratchet tie-down to pull them backwards when removing and the same tie-down to pull them back on.
It becomes really easy after removing carbs a few dozen times.

I have included a couple of photos of problems I struck when rebuilding my 79, note the advancer uint was so rusty it was not working, also the accelerator pump was rusted up and the plunger diaphram was cracked and needed replacement.
Just a few extra things for you to check.