Subject: Re: And now for something completely different....
Author: Bruce Giller
Date: Sep 13, 2001, 5:55 AM
Post ID: 1708221842
My experience with my homemade Viton gas petcock seals is that they
have been working well for over a year in my Eldo (both petcocks have
them). I punched them out of a 3/32" thick sheet I got at a local
supplier (http://www.potomacrubber.com).
I too was worried about any ripping or tearing that the rotor could
cause, so I polished the rotor face on my smoothest whetstone and also
rounded over the edges to remove any burrs that might be lurking. After
assembling everything, I turned the spring tension adjusting nut just
until it stopped leaking and no more. There seems to be about 1.5 more
turns left for future adjustments.
Did you lubricate your Viton gasket with silicone grease as you did the
vinyl one? I think that I did the same thing but I'm not really sure.
Bruce
'72 Eldo
Tom Bowes wrote:
| The last time we discussed the petcock gasket problem I thought I had it beat by using Viton for the gaskets. I am sorry to say that, alas, once again my efforts have failed. After about a month with the new Viton gaskets I started having fuel starvation problems at speeds over 65 MPH or when going up hills. Subsequent inspection of the gaskets reveals that they have torn in between the holes for the fuel passages and partially blocked the channel in the petcock rotor. This leads me to think that the problem is one of the mechanical strength of the gasket material, rather than the chemical makeup of it. Viton is supposed to nearly impervious to fuels and petroleum based solvents, and therefore should not have been adversely affected. So, "what's the problem?", I ask rhetorically. My guess is that the large amount of spring pressure on the rotor, and the lack of lubricating properties in gasoline simply put too much mechanical strain on the material and cause it to fail. I had an original petcock gasket that I had removed, which I took to the local rubber supplier. The owner looked at it and said that he guessed that it was made out of vinyl, and not one of the fancier sort of elastomers. I asked him if they had any, and he graciously provided me with a sample. At present I am experimenting with a viton gasket, lubricated with silicone grease, in the left petcock, and a vinyl gasket, also lubricated with silicone grease, in the right petcock. So far the vinyl gasket seems to be doing the trick, but I have as yet to get the bike up to freeway speeds to really try it out. Stay tuned, more info to follow. |