Starving & Flooding Carbs

[Peder]

I'm new to the forum so maybe this topic has been covered before.

I have a 66' CL77 that had not run since 1989, the bike is a beautiful unrestore original. After I got it and tried driving it I found it was running to rich. Both floats had holes in them which caused the float level to be to low. I replace the floats & bowl gaskets which were as hard as rock with some repos that I purchase, I do not recall the supplier.

I have had nothing but problems with the carbs flooding and gas coming out of the overflow. Two weeks ago I started the bike and could not keep it running unless I choked it and then it would not run at all. I shut of the gas and removed both bowls. The right one was full while the left was completely dry. I noticed that the gaskets were all wavie and destorted. I removed them and turned the gas on and gas flow fine out of both carbs.

The gaskets looked to big. I left them on the work bench over night and they shurnk back to normal size. I place one into a cup of gas for 1 hour and then removed it and placed it on the work bench with the one that was dried over night. As you can see from the photo the one that was in the gas is on the outside and is more than 1/4" larger. When in the carb it has not place to go but grow into the bowl where it interfers with the floats and keeps them from operating.

Has anyone else had this problem? Are there suppliers out there that make a gasket that does not swell? My guess is it is the ethanol that is in the gas that is being absorb into the gasket and making it grow.

[rustywrench]

Peder,
Been there, done this problem and so has a few others. You can carefully trim the gasket a bit and more often than not, squeeze the floats together to get them away from the gaskets. As far as a better supplier goes, I can't help you there. Rusty

[davomoto]

Peder,

Welcome to the forum! Nice to see another Bay Area member! I use Honda bowl gaskets whenever possible. The new gas is brutal on rubber carb parts. Are the pilot jets clear? Sounds like the bike has been sitting for a long time, and they plug easily.

Davo

[GG]

Hello Peder,

Ditto on Davomoto's remarks. Any rust in the tank will plug the small jets, so you will need to make sure they are free. You can remove them without removing the carbs - use a small, flat screwdriver. And put a real good fuel filter in the fuel hose-line for the time being. You might need to clean the rust out of the tank. Our ethanol-gasoline collects a lot of moisture, and this is a problem. I had problems for years with my small jets plugging, until I de-rusted my tank using the electrolysis system described on this forum, and then coated it with a special epoxy for gas tanks. Problems are gone for good! Haven't had one single problem with the small jets since.

On the float gaskets, you might just want to make your own - buy some THIN gasket material and use the float bowl as your guide. Use an X-acto or paper cutter to cut them out.

You will also need to set the floats according to the specs - these are on this forum, you can do a search. When you changed the floats, did you set the float level?

Don 't get flustered. Our Keihin carbs are simple, good carbs, and they are almost always fixable. You just need to go through the basics! Search this forum for info on setting up the carbs.

Good luck!

GG

[Peder]

Thanks for the replies. The bike seems to run fine if I drain the gas and let the gaskets dry out. The carbs have been completely rebuilt and I have not seen any signs of rust in the bottom of the bowls. The inside of the gas tank looks pretty clean but I may coat it to make sure nothing comes loose and fowls the jets.

It appears that my problem now is bowl gasket that swells and will not let the floats rise and shut off the gas or let the floats open to let in gas.

[GG]

Okay Peder,

Good work. You might try making the float gaskets of a non-rubber material, like the make-a-gasket material. Lightly sand the float bowls on a very flat surface (glass is best) with 400 grit wet/dry sandpaper just to ensure a nice flat fit. You shouldn't get any leakage from this - and they won't distort from the ethanol.

Get that cb running! :-)

GG

[Peder]

Through another hobbie supplier that makes gaskets, I had new gaskets made that do not swell when exposed to gas. I installed them this weekend and have been riding the bike this week without any problems. What a difference. If anyone is interested I bought them throught Scott Watson at Ron Fitzpatric Jeep Parts. They make their own gaskets and Scott now has the pattern for the carburator bowls.