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what causes a Rochester quadrajet float to stick?

S

sammi

Regular Contributor
The boat was not run for 2 weeks so obviously the gas had evaporated out if the bowl. The crusader 454 has run flawlessly for years. When I went to start it it cranked and cranked. It took 2, 10 second cranks before it started due to lack of fuel. That I understand, but once it filled the bowl it flooded out and stalled. I stuck a stick down the vent and tapped the float and I heard it drop into place. Problem solved. It ran fine after that. The carb has not been opened up for 3 years. What could the float been hung up on?
 
There is a lot of talk about brass floats showing up on aftermarket carbs and carb rebuilds, not sure if it is related. The most recent time I opened one of my quadrajets I found a lot of white crystal-like junk that was all over the sides and bottom of the bowl and interfering with the float. Apparently related to alchohol or water. Anyway.. just some thoughts.
 
a lot of problems are caused when people rebuild the carbs themselves. they focus on the float level, but not the float drop setting. the float drop setting can cause tons of problems if not set correctly.
 
I don't think the situation, as you described it, happened that way.....

if the float was stuck "up", it should have been holding the needle against the seat....if the bowl was "dry", the float would have been down and holding the needle open...if it was stuck there, using the stick may have freed it up, allowing the float to rise and close the needle.

What causes either the float or needle to stick - friction...the real question is friction from what. Usually, it is worn parts or dirt...if it happens again, I'd suggest getting an air horn gasket and removing the air horn so you can inspect the float bowl...
 
i am not suggesting that the float is stuck "up"......
if the float drop setting is set too low.....the float will be allowed to drop into a position where it will not rise when fuel starts entering the carb. also metal floats can leak around the soldered seam causing them to fill with gas. always shake a metal float. another common problem, is that soft style floats over time can become heavy, causing flooding. gm did make a small weight guage to determine this, but over the years, i just ALWAYS replaced the float to add quality to all my rebuilds.
 
a heavy float is a possibility for sure, but it is more probable that it is a incorrect float drop setting. i see this a lot. the only other thing that causes flooding, is when people use cheap rebuild kits wit the cheap needle/seat assys. ( i do assume you have a good,fresh, fuel filter installed)
 
All good points but it has worked fine for 3 years. It has never been opened up and, knock on wood, has worked fine the last 10 days.
 
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