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Discussion Starter · #1 ·
Hey everyone. I have a question about the floats in my carbs. I've had problems with my bike "marking its territory" lately. There has been gas coming out of the bottom of my carbs. First was the right side and now the left. Both times I was able to eventually get the floats unstuck by bouncing the back of the bike. Here's my question: Can the floats be replaced or would it be better to rebuild the carbs? I've talked to a few people and they have told me that this is a common problem with these older bikes. I'm relatively new to working on bikes so any information is really appreciated.
 

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It's probably not the floats "sticking" If anything is sticking it would be the float needle valves. Did you leave your petcock turned on? That's usually a no-no with these old bikes, as it makes it too easy for fuel to get into the crankcase if you have worn float needle valves or misadjusted floats. Start by verifying that your petcock doesn't leak when shut off. Put the fuel lines into a bottle (so the fuel doesn't evaporate) with the petcock turned OFF overnight. Any leak?

Then remove the carbs, and take out the pin holding the floats. Check the floats for pinholes or cracks. They can be very TINY. Submerging them may help check for leaks as well. The float needle valve is under the hinged end of the float. Check it's condition and replace if necessary. They're cheap insurance! If in doubt order new ones or post a picture here for evaluation. Basically all they have to do is shut off the fuel flow when the floats are raised. That can be "bench tested" with a fuel bottle hooked up to the carb.

Then re-install float needle valves and floats and check your float height. Search here for your proper float height settings. You can make a tool from an old credit card or plastic to measure/set the float height. All of the info is on here...

Remove all jets and verify they're clean with carb spray and possibly a TINY guitar string or TINY bristle removed from a brush. Verify that your fuel tank is completely cleaned out. You can use diesel fuel and nuts/bolts to shake it around and clean it out. Be sure to rinse it out after and count the nuts/bolts. Also remove your petcock when doing the cleaning so it's not damaged. You'll want to clean it seperately anyway.


GB :mrgreen:
 

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Discussion Starter · #3 ·
Thanks for the info. I'll check that stuff out and post when I have more information.
 

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Discussion Starter · #4 ·
I started turning the petcock off after these leaks started happening and no gas leaks out overnight. When it happens, it's not so much a dribble of gas as a steady leak from the bottom of the carbs. The right carb started initially, then the left carb. It switches from one to the other. For example, if I'm at a stoplight, I'll start smelling gas and i'll look down and see one of the carbs leaking. When I start riding from the light, I'll bounce the back of the bike a bit and it usually stops it. I haven't tried taking the carbs off yet but plan on it as soon as work calms down a bit. Otherwise the bike is running great. Thanks again for the info.
 

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When you turn the gas to ON the bowl fills or overfills. When you turn the gas to OFF if the petcock is working the bowl will not receive more gas.
The causes of gas coming out the drain are:
Bad gasket/washer for the drain screw
Cracked overflow tube
Bad float valve tip
Crap in the float valve
Bad Float
To find out which it is you will have to access your bowls.
Disconnect the exhaust at the rear and loosen it at the front. Drop it down some and take off the side covers. Prepare for some gas leakage. Get a small bucket and some rags. Rubber gloves. NO FLAME or SPARKS. Work outdoors if you can. Have the petcock OFF and drain the bowls. Take the bowls off. Fill the bowls with gas on the bench and see if the drain screw and the overflow tubes hold. To see if the float valve works....get ready for gas... open the petcock. Gas will start coming out of the float valve. Raise the float gently. If the valve seats and gas stops either you washed out the crud or the float is bad or needs adjustment. If the valve won't seat, it's the valve tip or the seat. Use a mirror and a magnifier to inspect the seat. This is all argueably easier and safer to do with the carbs off the bike but I've used the above method successfully to save time.

Edy
 

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I am having the exact same problem with my bike. The only thing I haven't checked is a crack in the stem. Hopefully that's it.
 

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I had a cracked stem also - I sleeved it with a chunk of the hose that plugs into the bottom of the bowl - worked great :)
 
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