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Fuel overflowing

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L

Leew

Senior Member
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Hi Chaps

Back from my vacation and back to another AH problem and question.......
When I switch on the ignition on my 100/6 occasionally the overflow on one of the cars spills out fuel where obviously the float does not cut off the fuel once the bowl is full
Also my fuel pump continues to run / click
This happened the first time I switched on the ignition but on the right hand carb HD-6's ?
So I took them apart cleaned them, fitted new filters and put them back together
Been fine for a while, this afternoon switched on ignition after the car sat for three weeks........... left hand carb overflowed
Do we all think this is just cleaning?
Ta
 
I had similar problems. One of the floats had a leak and was partially filled with gas. Unrelated to the float bowl leak problem, I had further overflow issues and the problem was solved when I switched to Grose jet float valves. Some folks prefer to stick with the Viton needle type float valves.
 
Last edited:
Grose jet float valves

Get U some LEEW and your problems will go away--:highly_amused:
 
nevets said:
... I had further overflow issues and the problem was solved when I switched to Grose jet float valves. Some folks prefer to stick with the Viton needle type float valves.
Click to expand...
I'm one of those who has had better luck with the Viton needle type float valves.
 
Thank you gentleman, after much deliberation and rooting around the interweb I have decided to go with the SU uprated sprung Vitons

I'll keep you informed on my experiences

ta
 
Is it the valve or a float that's starting to fail?
 
I sometimes have that problem if my car has set for several months. The fuel will slowly evaporate and may leave behind some "gunk" or varnish that keeps a float from floating. I fill the carb bowls, turn off the pump and let the fresher fuel dissolve the gunk. The floats pop up and shut off the valves and I'm good to go off to the filling station to refuel.
 
I had the same problem on my 100. It had the older metal floats with a soldered joint and the floats filled with fuel. Interestingly, I could find no leak when the floats were cold so the joint must have expanded when heated and allowed fuel to enter. Went with the seamless black plastic floats and no problem.
 
Common problem, you can tell if it is the float or valve by rapping the offending float bowl lightly (I would use a screwdriver handle, but a light plastic hammer will do the trick as well). If the valve is sticking open, the rapping will most likely loosen is sufficeintly for the float to, well float and close the valve. If the float is sinking because it is leaking, no amout of rapping will help.

Cheers,
Dan M.
 
I just rebuilt my H4 Carbs and installed the grose jet valves, I notice when I turn the motor off after a few mins I get about a 1/2 teaspoon of fuel puddled in the intake after the air filters. I adjusted the float level 7/16" like the book said. Does it sound like it might be out of adjustment or the new grose valve leaking? I have a brand new set of the original valves and debating if I should just go back with the old type.

John Turney said:
I'm one of those who has had better luck with the Viton needle type float valves.
Click to expand...
 
CessnaTPA said:
I just rebuilt my H4 Carbs and installed the grose jet valves, I notice when I turn the motor off after a few mins I get about a 1/2 teaspoon of fuel puddled in the intake after the air filters. I adjusted the float level 7/16" like the book said. Does it sound like it might be out of adjustment or the new grose valve leaking? I have a brand new set of the original valves and debating if I should just go back with the old type.
Click to expand...

Folks have had issues with the Grose valves in recent years. If you have the viton-tipped ones, they would probably be best.

Should add I have Grose valves in my HD8s and have never had any problems - however they could be the old ones from 20 years ago.
 
CessnaTPA said:
I just rebuilt my H4 Carbs and installed the grose jet valves, I notice when I turn the motor off after a few mins I get about a 1/2 teaspoon of fuel puddled in the intake after the air filters. I adjusted the float level 7/16" like the book said. Does it sound like it might be out of adjustment or the new grose valve leaking? I have a brand new set of the original valves and debating if I should just go back with the old type.
Click to expand...

Once in a while the fuel will not remove an anti corrosion finish placed on Grose Jets so they need to be sloshed around in Acetone and wiped dry before reinstalling.
 
Removed the grose jets today and replaced with new viton valve and have no leaks. I'm not a fan of the "bulletproof" grose valves.

steveg said:
Folks have had issues with the Grose valves in recent years. If you have the viton-tipped ones, they would probably be best.

Should add I have Grose valves in my HD8s and have never had any problems - however they could be the old ones from 20 years ago.
Click to expand...
 
There's no "spring" in the grose jets to hold them tightly closed and sealed and the engine vibrations could allow them to leak fuel. It might not be a lot always, but the potential is there. The ones I had back in the '70's were good for several years before they started leaking. I don't use them anymore.
 
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