I thought I was minutes away from a ride on my new rebuild then, when I put gas in the tank, the petcock was leaking from the mating serface with the tank. The O ring is hard and not standing proud of the mating surface. I've tried several fixes that haven't worked. Is the only way to fix it a new soft O ring? It's beginning to look that way to me.
If it's an '82 petcock the 0-ring is reasonably common - even amongst the Japanese makes. If it's the '83 petcock, it may be more difficult to find I'm told.
I did an interweb search for "rejuvenating rubber parts" and the like. Amongst others, I came across this Triumph forum post where someone compiled results from other forums based on number of times cited. Using wintergreen oil was a new one on me although according to some threads can be easily overdone. The resultant giant mutant o-ring may be rendered unusable. This may be true of carb sprays too.
One thing I didn't see suggested was fork oil. Don't some advertise having additives to swell old tired seals?
The thread:
http://www.triumphrat.net/classic-vintage-and-veteran/221577-what-will-soften-rubber-parts.html (http://www.triumphrat.net/classic-vintage-and-veteran/221577-what-will-soften-rubber-parts.html)
Auto trans and power steering stop leak products work by swelling rubber parts.
Thanks. I hadn't thought about the possibility of rejuvenating the old O-ring. I'll go to a shop that repairs small engines tomorrow and if they don't have anything I'll run by the AutoZone and get some automatic transmission fixer upper.
I spent about 4 hours jacking with the petcock leak before really looking at it closely and realizing there was a snug fitting rubber gasket on the front, non-leaking bolt that hold the petcock on but no such seal on the rear, leaking, bolt. I didn't have proper washers but I did have some small O rings so I put one on the leaking bolt and no more leak.
BUT, I've still got a problem with the petcock. I can't get gas out of the front most outlet of the petcock. When I turn to the Prime position I get gas out of the rearmost outlet. When I attach a piece of hose to the vacuum port and suck on it I get gas out of the rear most outlet but still none out of the front outlet. Also, the gas going into the bottom hose is not getting to the carburator. It would run completely out of fuel. Finally I made a short extension hose and hooked the back outlet to the hose going to the top of the carbs and just blocked off the other outlet and the bike runs fine now.
I'm done for the week. I took a short ride and noticed the front forks are binding on the wiring harness, so I've got to remove the fairing to fix that. When I returned I noticed a small oil leak. I'll tackle those details next week.
'83 petcocks have two spigots. One is outbound to the carbs. The other is return to the petcock. No fuel should ever come out of the return spigot.