Subject: Gas Cap Woes
Author: Greg Bender
Date: Jan 5, 2005, 11:52 AM
Post ID: 1718157935
My tank has the screw on type gas cap. The original cap - even with a
new gasket - allowed fuel to escape through the top vent holes. The fuel
then ran down the tank...not to my liking.
I purchased a generic vented gas cap from Dennis Kirk
4XVJGZBLKEEGJLA0WTISM4VMDK0NCIV0?catId=211&leafCatId=21105&skuId=h18199)
and it seals perfectly. I never get any gas leakage from the cap. It
allows air in, but it does not allow excess pressure to escape.
Normally I wouldn't think this would be a problem, as I would expect a
decrease in the fuel level to create a vacuum inside the tank...easily
solved by letting fuel into the tank. However, I have found that excess
pressure is built up inside the tank...and is especially noticeable when
the tank is 1/3 full or less and/or when their is a great temperature
difference between the fuel and the ambient temperature. When I release
the gas cap, I can hear (and feel) air escaping out.
Although I don't understand the physics of it, this actually starves the
engine of fuel from time to time on my rides...the engine will come
close to dieing and I have to loosen the cap to allow the excess
pressure to escape.
I think John Ulrich and/or Mark Etheridge may have suggested drilling a
strategically placed hole in the inner workings of the cap, but I'm not
sure where that location might be. Does anyone have any thoughts or
suggestions for improvement?
Regards,
Greg Bender
1971 Ambassador
2000 Quota
http://www.thisoldtractor.com/gtbender