I just picked up a 3/4 spud gasket today, paid $3.15 total from a local plumbing store. I can't wait to try this.

@Boule'tard
have you had any problems with the gasket being too good of a seal, creating a vacuum as you ride and eventually starving the engine for gas til you pop the cap again?

I only ask because I'm trying to find one locally and you seem to have had the most success with your sized gasket.

There is a valve in the cap behind the lock cylinder with a ball in it. If you tip the bike over the ball rolls down to plug the vent. It stops gas from pouring out but it will still drip, or maybe I didn't lean it quite far enough when I put it down last week, or possibly the ball is spring loaded and my spring has rusted away. I think it vents through the key hole, as I can't see anyplace else for it to vent.

I ended up taking off my 3/4th spud washer that had no treatment on it because it eventually started leaking after 2 weeks, and some weird brown odorless stuff starting dripping down the tank. Since I have had the original washer back on I haven't had any leaks, it seems it may have just needed to be rotated.

I tried to fit the 3/4th spud gasket under the original washer for a super tight seal, but I couldn't get the cap to lock on the tank. I'm going try a sediment bowl cork gasket though. Thanks!

Ok so I finally started riding the bike last and now I have started slow fixing the minor stuff ( cap head leak / head retouque ( in process ) ). Also working on the gas cap fix got a Honda factory gasket that works perfectly and I'll report back in the next week or so when I get back on the road

Built2Last wrote on 08/07/11 at 18:18:45:


I doubled up the original and a different rubber washer that fit just last night. Took a mild amount of pressure to close the cap and it felt like it fit very snug.

Fast forward to my ride to work this morning and I thought I ran out of gas (90+ miles on the tank so it seamed about time, but reserve wouldn't let me start it either) Pop the cap back off and slosh it back and forth to see if there was any left & I could see it in the bottom. Switched it to prime, put the cap back on and it fired right up. Since I was just about out of gas anyway I stopped and topped it off and put the petcock back in the ON position.

Lunchtime ride home was just fine, but on the way back it acted like it was running out of gas. Died on me and I pulled off the road. Thought it might be the new gasket and listened close when I opened the cap, sure enough you could hear the air go into the tank when I popped the seal. Put the cap back on and it fired right up so I could be on my way. I guess when I get home today I will take out the 2nd gasket and try again.

arteacher wrote on 08/09/11 at 16:24:05:


I've had that cap apart 6 or 8 times trying different things and this last time I did take some compressed air and blew it through the vent-no problem at all. Just going to be more careful and fill it a little less.

I received this gasket from this exact link on Tuesday. (Excellent seller, very quick shipping) Replaced it on Wednesday night and had to gas up at lunch today. It seemed like it was a tighter seal than the others I had tried so I had high expectations. Maybe too high...I filled it really full up the neck then put the cap on. Rocked the bike side to side some and none came out. Rode the 1/2 mile back to work and no spills, I was happy   About an hour later I had to leave to run an errand. When I tilted the bike back upright gas poured out the cap all over the tank   The heat of the sun had heated the tank so much that it must have caused the gas to expand or something Guess I'm just going to have to learn to fill it less.