How often do carb floats get soaked with gas and heavy so that the fuel level gets too high and the mixture gets too rich at highway speeds?
The floats are that kind of black or dark gray plastic like a very dense foam that I believe was/is commonly used. It looks like the same stuff used for the float in my '77 Chevy.
The problem is with my motorcycle, but I guess it wouldn't be much different for cars.
1976 CJ360T: inline twin, SOHC, CV carbs with choke plates
When it happens, it happens. How long it takes depends on the specific formulation of the Nitrophyll used to make the float, and the specific formulation of the gasolines used.
It took 20 years on my old Chevy for it to get heavy enough to be a problem. Then I put in a "good" one that I'd been saving for 15 years in the basement. I'm just about out of old parts. The frame is rusting badly. Soon I'll have to buy a whole car.
On 2005-08-08 snipped-for-privacy@themattfella.zzzz.com said: >Newsgroups: rec.autos.tech >How often do carb floats get soaked with gas and heavy so that the >fuel level gets too high and the mixture gets too rich at highway >speeds. >The floats are that kind of black or dark gray plastic like a very >dense foam that I believe was/is commonly used. Never, in the 10 years I ran my bike shop.
If the fuel level is too high, there will be gas running out of the carb bowl overflows.
At the bottom of the float bowls is a screw for draining the bowls. I made a tool for checking actual running fuel level by drilling out the center of a bolt that fits there (short 6mm, easier in a lathe), soldered a short piece of metal tube into it to take some clear plastic tubing. Gives me a sight gage. Most carbs run their fuel level about even with the bowl joint (gasket).
With foam floats there should be a weight spec somewhere. Check 'em.
Do you know how to set float level? (That's done with the carbs removed, you know?) You'll have to balance the air flow through them after, both at idle and lightly opened. Got a set of matched vacuum gages and the vacuum port adapters, or a Uni-Syn?
Tom Willmon near Mountainair, (mid) New Mexico, USA
Net-Tamer V 1.12.0 - Registered
I just looked at one of the floats and I find that the valve-actuating tang can't be bent---the float level is not adjustable.
Now if I can just find a weight spec for the float and a scale sensitive enough to weigh it ...
Mopar used that kind of plastic back in 70s- this problem was very common. Easy fix, though, once you recognized what the problem was.
As an aside, I didn't realize the effects of flooding on an engine in very cold weather. When the carb on my slant six was going this way, I flooded it several times while trying to start it when weather was down in twenties or less. Problem is, it takes an hour or more to clear it out. Just flooring the throttle and cranking doesn't do it.
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