stock petcock

[CaptonZap]

Howdy,

Here is my take on this situation.
If you got rid of the original bolts, you have problems.
As Skids pointed out, the washer head bolts provided a sealing surface from the underside of the bolt head to the surface of the petcock around the bolt hole. Which is to say that a fiber washer between the two surfaces sealed off any gas seepage through the joint.
Unfortunately, an Allen head does not have anywhere near the same area under the head as did the original bolts. So a fiber washer is not going to work, unless you can solder a washer to the bolt, thus making a replacement for what was there. The solder would seal the gap between the shank and the washer, and the washer would provide the sealing surface for the gasket washer between it and the petcock.
Another solution would be to get a 45 deg countersink cutter and countersink the bolt holes in the petcock such that a thick O-ring would be compressed under the washer on the Allen bolt, and make the seal between the shank of the bolt and the petcock flange. That would require some pretty specific machining, and is not advised from this side.
A better solution would be to Bing someplace like this place,
http://www.nutsandbolts.com/bolts-me...-c-31_161.html
and buy something that would be a hex head replacement for the originals. The 16mm length mightbe about right.

Good luck, CZ

[conquest87tsi]

CZ, I understand your concern. However, I have some rounded head allen bolts as well as cap. The round head have the same area as a philips. The bolts I have are 16mm length, which is longer than the originals.

[Petersg_99]

I got rubberized washers at Ace hardware and tried to install the petcock with regular bolts, one held, but the other didn't. I ended up going back to Ace and buying flanged bolts to get the additional sealing surface. They've worked fine for the last month or so...

The large round O-ring is for sealing between the tank and the petcock.

CZ, I understand your concern. However, I have some rounded head allen bolts as well as cap. The round head have the same area as a philips. The bolts I have are 16mm length, which is longer than the originals.

[CaptonZap]

CZ, I understand your concern. However, I have some rounded head allen bolts as well as cap. The round head have the same area as a philips. The bolts I have are 16mm length, which is longer than the originals.

Great, then the fiber washers, or ones punched out of neoprene sheet would work just fine. I coat both sides of the gasket with Gasgacinch gasket sealer. Belt and suspenders kind of guy.
The holes go all the way throught the tank flange, so as long as the bolts have threads all the way to within an eighth of an inch of the head, you should not have any problems with the 16mm bolts.

CZ

[conquest87tsi]

Feel like I may be stealing a thread, but what the hell. better than starting a new one right? So I stopped at Ace during lunch and got some washers. Only thing is I didn't like the gap between the fiber washers and the bolt threads so I got rubber washers instead. Now I get to see if they hold up to fuel.

[XS1100_OEM4ME]

Fiber

Feel like I may be stealing a thread, but what the hell. better than starting a new one right? So I stopped at Ace during lunch and got some washers. Only thing is I didn't like the gap between the fiber washers and the bolt threads so I got rubber washers instead. Now I get to see if they hold up to fuel.

The reason Yamaha used fiber instead of rubber IMHO, is so you can compress the "O" ring gasket between the tank and petcock to seal it tight. The rubber may work fine if it is tough enough

[crazy steve]

...so I got rubber washers instead.

The problem with rubber is those screws need to be tight; I suspect you'll find the washers will squeeze out before you get a leak-proof seal.

Hard nylon washers will work too...

[conquest87tsi]

I looked at the nylon and fiber washers but felt like they weren't even close to tight enough on the threads of the bolt. I definetly hear what your saying about the rubber washers just smooshing. Maybe I'll check out the fiber again. I'm thinking a rubber, fiber/nylon combo might work. Bolt would spin on the washer and not turn the rubber seal so much.

[XS1100_OEM4ME]

Fuel

here are a few hundred to pick from

https://www.google.com/webhp?hl=en&t...w=1280&bih=675

http://compare.ebay.com/like/3705077...Types&var=sbar

[bikerphil]

MikesXS has the correct bolts and fiber washers for a buck or two, scroll down...

http://www.mikesxs.net/products-34.html#products

[XS1100_OEM4ME]

+1

MikesXS has the correct bolts and fiber washers for a buck or two, scroll down...

http://www.mikesxs.net/products-34.html#products

Phil is the man

[CaptonZap]

I looked at the nylon and fiber washers but felt like they weren't even close to tight enough on the threads of the bolt. I definetly hear what your saying about the rubber washers just smooshing. Maybe I'll check out the fiber again. I'm thinking a rubber, fiber/nylon combo might work. Bolt would spin on the washer and not turn the rubber seal so much.

I think you are over thinking this washer thing.
It, the washer, doesn't have to be a tight fit on the threads for the assembly to seal. What happens is that the washer seals against the flat area on the bottom of the bolt head, which holds the washer against the flat portion on the petcock base, which presses the base against the o-ring, which seals against the tank. All of the surfaces are flat, and can benefit from a dose of gasket cement.
The threads don't have to seal.
CZ