Weber float problem

jjmohler · 11-23-2008, 01:20 PM

I started the process of checking and adjusting the floats on my Weber 40's the other day and all went well until..... Upon rechecking that they were all 'spot on' I found that one of them is erratic. If I check it 3 times it might measure differently each time. By now I have checked it MANY times. Sometimes it measures 'in the ballpark' in the gage, the next time nothing at all, the next time close and then rises and overflows the gage and then drops down to above normal. Most times it overflows the gage. This is in spite of changing shims and/or adjusting the float tab in-between tests. I do have fuel that has overflowed into the carb throat. I'm stumped, does anyone have any in-site?

Thanks John

Tooth911 · 11-23-2008, 02:08 PM

possible bad needle valve

jjmohler · 11-23-2008, 02:48 PM

Sorry,
I forgot to mention, I have replaced the needle valve and float with new units. No change. Thanks for the reply.
John

911pcars · 11-23-2008, 03:58 PM

What is the fuel pump pressure?

Are you using a pressure regulator?

Try swapping needle and seat sets with another bowl.

Sherwood

jjmohler · 11-25-2008, 08:46 AM

Sherwood,
Thanks for the reply. I think that I have found the problem, float hanging up on the carb body. I did just install a regulator but have not yet installed the gage. Do I understand correctly that 3-4 lbs is about right?
John

911pcars · 11-25-2008, 09:45 AM

Quote:

Originally Posted by jjmohler

Sherwood,
Thanks for the reply. I think that I have found the problem, float hanging up on the carb body. I did just install a regulator but have not yet installed the gage. Do I understand correctly that 3-4 lbs is about right?
John

Good job finding the issue.

Yes. 3-4 lbs is about right. Install filters before the gauge so any pressure drop (and thus volume drop) from clogged filters reflects in the gauge display.

Sherwood