1979 9.8 Carb Bowl

keithb7

Petty Officer 3rd Class
Joined
Dec 16, 2024
Messages
75
I have been struggling to get the carb bowl to seal. I also ordered a new OEM Quicksilver gasket kit. It won’t seal. I’ve tried adjusting the float level incase it was over fueling. No improvement. The old cork bowl gaskets seem long gong. The ethanol in todays fuel may be a contributing factor. The bowl seal swells, enlarging. It won’t go back in its groove. Left to dry for a week, the seal seems to shrink and then is too small. I tried some tricks that were mentioned on FB groups. Boil the seal. Freeze the seal. No improvement.

Seen in the photo is the extra seal material that will not fit into the seal’s groove, once it has become enlarged. Has anyone had any success with an RTV type gas-proof tube of goop to shape and my my own seal? Or perhaps cut the OEM seal, taking a section out to makke it fit. Then applying said gasket filler to the gap to get it to seal. Any tips appreciated as this is frustrating.

i am not aware of any ethanol free fuel here in Canada.

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keithb7

Petty Officer 3rd Class
Joined
Dec 16, 2024
Messages
75
Following up to share success in resealing the bowl.

I cut the seal. I fit it in place and cut off a piece as it was too long. I fit the seal tightly in its grove ensuring a good tight fit. Removed seal. Carefully applied a thin layer of Permatex Motorseal sealant which does not break down when in contact with gasoline. I put a little extra where the cut seal joins. I let it set up, carefully pushing the seal back in place where it tended to move a little. Sealant was given time to set up. All appeared good. Put a thin layer on the outer surface of the seal where the bowl contacts it. Used my finger to spread and smear a thin layer. Let it sit for 20 mins. Installed bowl and tightened it down. Re-installed carb and let it sit for a few hours to let the sealant to cure. Hooked up the fuel line. Primed bowl with the hose bulb. No leaks. Started engine ran for 20 mins at various RPM. No leaks.

How long will it last.? How long until sealant breaks down? Will it? Time will tell. Will test on my boat on the water later today. I will update this thread as time passes. So far this is the first time the bowl has sealed properly despite my efforts. Wish me luck.

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Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,263
I used something similar to seal the gaskets on my fuel tank sender. It seems to hold up. Hopefully you have the same luck.

I am concerned about you not being able to find a carb bowl seal that works. Is it possible that you got some old stock (pre-etoh) when you bought the new gaskets? The swelling of the seals should not happen.
 

dingbat

Supreme Mariner
Joined
Nov 20, 2001
Messages
16,491
That is an old school compression (seal) gasket. One time use only.

Had the same issue in my old 2 stroke golf cart where the orginal gasket is NLA.

It took some searching, but was able to find the proper “square” , nitrile seal for the groove. Had to buy a box of 100 (life time supply +) but $25 well spent given the alternative.

I would not use gasket maker on a carb unless deemed “disposable”. When the stuff breaks down you end up with a carb full $rap. Clog a jet, run lean and blow up the motor
 

keithb7

Petty Officer 3rd Class
Joined
Dec 16, 2024
Messages
75
Agreed @dingbat if/when the silicone breaks down if will plug up carb orifices. I wanted to do something to prove where the leak was coming from. My mind was settled when this worked. I will consider finding a quad ring to seal it up long-term. Something ethanol-proof.
 
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