1982 CB650 Nighthawk carb question

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red66stang · Sat Apr 30, 2005 8:16 am

I went to put gas in my bike the other day as it was completely bone dry. I started pouring the gas in and it started to leak out from the carbs all over the place. What would cause this?

From my automotive carb experience, I'm guessing the float valves were stuck open. It was leaking from all 4 carbs as far as I could tell, so is there usually 1 float valve or does each individual carb have one? I pulled the carbs off today figuring they need to get cleaned out anyways but would like to have some idea why they would leak like that. Thanks.

Nate

shoey949 · #2 Unread post by **shoey949** » Sat Apr 30, 2005 1:01 pm

yeah, actually I'm having the same problem on the exact same bike! Although it's only on one carb, but I got it running and it idles great, not bad for a 150 dollars

red66stang · Sat Apr 30, 2005 10:59 pm

yeah, a local shop wants $120 to go through the carbs and stuff. I'm tempted to do it because I have the bike sold once the gas thing is fixed. Do you have the ability to take some pictures of the vacuum lines around the airbox on the righthand side of the bike? Mine has a bunch of hoses that aren't attached to anything.

Quick 350 · #4 Unread post by **Quick 350** » Sun May 01, 2005 4:26 pm

You'll find on those CV carbs that any time they run dry you'll have many different problems.

1- Slides get stuck up.
2- Floats get stuck Open or Closed.

when fuel starts to leak out a good tap on each carb with some thing hard will solve this unless carbs are in need of a good cleaning.

These carbs are relatively easy carbs to work on once you get over the fear of breaking into them.

One thing to remember is to be care full of the slide diaphragm these are hard to come by and not to cheap.

On another note I am parting out a complete 82 650 night Hawk motor as well as a set of good carbs all offers welcome.

PICs can be sent on request.

Good Luck!!!

and post back!

Mike

red66stang · Sun May 01, 2005 9:53 pm

If the carbs off your nighthawk you're parting out are in good condition and would be able to be bolted on and go, I'd be interested in those. Other parts I want are:

Right and left side covers (blue preferable)
Complete airbox or just the rear part (the one that holds the filter)
Non-leaky forks
Gas Tank (mine's a bit rusty so wouldn't mind replacing rather than de-rusting)

My bike is mostly complete but I'm trying to sell it to make some space. Guy said he'd buy if it didn't leak gas everywhere. Let me know what you'd want for those parts.

Quick 350 · #6 Unread post by **Quick 350** » Mon May 02, 2005 3:36 am

The engine was actually placed in a 80 CB 650 frame.

The guy never could get it running because he didn't have the CDI box and had no clue on the wiring.

I believe the side covers are different but the forks are the same and are in good condition $20.00 + shipping and they are yours.

The carbs have been dry for at least 3 years that I know of so they will need to be broken down and cleaned.

I'll take a better look at them and let you know what I think.

If you would like PICs P.M.-me with your E-mail and I'll send them out to you

Mike Haverhill, Mass

shoey949 · #7 Unread post by **shoey949** » Thu May 05, 2005 9:05 am

does anybody know of a gas-proof liquid gasket kind of thing? I have a leak from the bowl gaskets on 2 out of the four carbs, but don't want to have to buy 2 carb kits just for the gaskets?

#8 Unread post by **9000white** » Thu May 05, 2005 9:41 am

gasket stuff---PERMATEX--HYLOMAR--HPF gasket dressing and flange sealant.item#25249--i got it at auto zone.it works.gas wont dissolve it like silicone sealant.