Series 80 Leaky Carburetor

[Author nameAuthor names are only available to PAS members.]

Another question regarding my (well, my wife’s actually) 1925 Series 80 (and thank you again to all who have helped me before). The Pierce carburetor continues to leak out the bottom no matter what I (and a few others) have tried to do. It leaks directly on the exhaust pipe, which is not a good thing. I have tried repacking the seal around the bottom needle valve with various materials but soon it leaks again. Has anyone else experienced this problem and have you found a solution? I want to keep using the original carburetor but if all else fails, is there a substitute just for driving purposes? Thank you in advance. Tom

[Author nameAuthor names are only available to PAS members.]

Tom,

Sorry to hear about the carb that continues to leak.

Safety concern about dripping gas on exhaust–install the left side splash pan (hard to twist into place) and gas will no longer touch the pipe. To remove or install the left side splash pan, you will have to remove the left front brake rod.

Re leak itself (you may have addressed some or all of these already):

1. Remove float from its chamber (no need to remove carb) and check it carefully for a leak, indicated by gas inside the float — shake the float and listen. If there seems to be none, confirm by heating a pot of water on the stove (short of a boil–maybe 160-180 degrees) and submerging the float entirely, looking for bubbles. (Remove quickly if you see bubbles from float, as gas inside float may expand rapidly and pop the seams.) Leaking float is common due to brass deterioration and will cause overflow that the gasket under the main jet can’t handle.

2. Also check float height adjustment. The two pin-mounted ‘arms’ that bear on the top of the float (to control gas level) wear but can be turned over to give a new round surface if that hasn’t been done before. There’s a gas-level plug on the front side of the carb bowl–with vacuum tank valve turned on, you should get just a few drops of gas when this plug is removed.

3. Original gasket between main jet assembly and carb body was a complicated SINGLE die-cut piece that consisted of two concentric circles with four arc-shaped slots between them to accommodate the holes. I don’t know of any CORRECT reproductions being available, but have always had problems with the common substitute of two separate round gaskets. It will take you 30 minutes with a grade-school compass and an exacto knife to make a suitable gasket.

4. Try a couple of turns of teflon string under the main jet’s gland nut.

Hope some of this helps!

George

[Author]

Posts