Fuel Cap Gasket

[Spartanman]

Howdy, the fuel cap rubber gasket on my 1981 xs1100LH is deteriorated. The parts manual doesn't call out a part number for the gasket. I have seen some NOS gaskets advertised, but don't know if that is the correct one or not. Anyone know the part number and/or where to find one?

Thanks

[DiverRay]

IIRC, the XS650 site, mikesxs.com ?, has them. the special fits multiple models, unlike the standard tank.

[robbo]

Yamaha part number: 2m0-24641-00-00

http://www.ebay.co.uk/itm/Yamaha-2M0...cAAOSwfvRZf8ak

[Spartanman]

Thanks

IIRC, the XS650 site, mikesxs.com ?, has them. the special fits multiple models, unlike the standard tank.

Thanks - they have them in stock.

[jetmechmarty]

Historically, the Mike's XS part is inferior and won't last. OEM is available everywhere. Look at the fiche for the XS1100SH. The same gasket fits many bikes.

Your filter in the cap is probably rotten, so when you change the gasket, the tank won't vent and you run out of gas. I made a new filter from a piece of Scotch Brite.

[BowlingSS]

My gasket seems to be bad. How can you tell? I do not think mine is venting right.

Bill

[jetmechmarty]

My gasket seems to be bad. How can you tell? I do not think mine is venting right.

Bill

Not venting means you run out of gas with a full tank. A deteriorated gasket will show cracks in it and be hard. There is a filter in the cap and it's rotten. It is plugging the vent. I made a new one from a small piece of Scotch-Brite. The tank is now venting through the deteriorated gasket. A new gasket without addressing the filter will plug it up good!

[dansmith65]

o-ring alternative

I found some info here about alternatives to the OEM route: http://sense.net/~blaine/gascap.html

I got a neoprene rubber o-ring from the hardware store that seems to fit/seal well. I don't expect this material to last, but at least I know the correct size now. My test for "seals well" is that my garage smelled strongly of gas before I replaced the old one, and now it doesn't; very scientific!

If anyone wants to go the o-ring route, here's the size:

• dash size: -222
• ID: 1.5"
• OD: 1.75"
• cross section: 0.125"

If you got one made from Buna-N Nitril, or Viton, I bet they would last just fine.

P.S. You might be able to step up to a thicker cross-section -325, but I haven't tried that.

[skids]

Make sure that the cap vents to prevent "vapor lock."

[MaximPhil]

I found some info here about alternatives to the OEM route: http://sense.net/~blaine/gascap.html

I got a neoprene rubber o-ring from the hardware store that seems to fit/seal well. I don't expect this material to last, but at least I know the correct size now. My test for "seals well" is that my garage smelled strongly of gas before I replaced the old one, and now it doesn't; very scientific!

If anyone wants to go the o-ring route, here's the size:

• dash size: -222
• ID: 1.5"
• OD: 1.75"
• cross section: 0.125"

If you got one made from Buna-N Nitril, or Viton, I bet they would last just fine.

P.S. You might be able to step up to a thicker cross-section -325, but I haven't tried that.

Hi Dan, I expect you are correct that the Neoprene will not last ...as long as the Nitrile or Viton would.... but if it is an easy change and cheap it may be the best solution.
Phil

[dansmith65]

Good point! I can't verify that it wouldn't cause issues because I haven't ran it since putting it on. I did just measure the old gasket's thickness and found it to be 0.1". So the o-ring I mentioned is 0.25" thicker, but it's also round, so would likely compress down to 0.1" fairly easily. It's possible that it may put slightly more force on the spring that seals the vent, but I doubt it put's enough to cause an issue. With that in mind, I wouldn't recommend trying the -325 oring after all.

Also, I'm finding that this neoprene o-ring is already expanding. When I first put it on, it fit perfectly and stayed put when I opened the cap, now it falls off when I open the cap.

[MPittma100]

Oem

Good point! I can't verify that it wouldn't cause issues because I haven't ran it since putting it on. I did just measure the old gasket's thickness and found it to be 0.1". So the o-ring I mentioned is 0.25" thicker, but it's also round, so would likely compress down to 0.1" fairly easily. It's possible that it may put slightly more force on the spring that seals the vent, but I doubt it put's enough to cause an issue. With that in mind, I wouldn't recommend trying the -325 oring after all.

Also, I'm finding that this neoprene o-ring is already expanding. When I first put it on, it fit perfectly and stayed put when I opened the cap, now it falls off when I open the cap.

The o-ring will NOT work. Be safe and get the right Yamaha part.

[dansmith65]

The o-ring will NOT work. Be safe and get the right Yamaha part.

I know the neoprene one I have now won't last, but I'm also not using the bike now; it's just there to keep the fumes in the tank while it sits in my garage. I'll be working on it this winter, and riding it next spring. I'll likely replace it with a o-ring of the same size, but appropriate material. I haven't decided/settled on it, though.

Is that what you were referring to? If not, can you explain what aspect of it won't work, and why you think that? Like, it won't seal, or it won't vent, etc.

[MPittma100]

Correct Replacement

Past experience in using the wrong part allows me to tell you that it will not work. Why take the chance when the correct part is available? It will leak, but has nothing to do with cap venting. The vent is another part of the cap.

[CaptonZap]

http://www.xs11.com/forum/showthread...gas+cap+gasket

CZ