82 GS850L Petcock Leak

[Sniper]

Ok, my petcock has been leaking slightly since I bought my bike last year, so I figured it was probably because the previous owner tried to fix it with a repair kit (I could tell because he put it back together incorectly). Instead of messing with it I bought a new one on ebay for 50 bucks and put it on this past weekend, and to my horror :shock: it still leaked. I got to inspecting it closer and found it was leaking from under both bolts that hold the petcock to the tank. My question is, should I try to find new bolts (and where to look), and should there be rubber washers between the head of the bolt and the tank (mine have none)? Thanks guys, this site is great!

[Steve]

The ones that I have seen have o-rings that are formed to the base of the petcock. They will be a long oval, and my have compartments in them to surround each bolt.





It's #16 in this diagram, part number is 499432-001, cost from Bike Bandit is $1.85.



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[JTsGS650]

I had the same problem on my '82 650, the PO slapped some goop around the petcock and bolts in an attempt to stop it from leaking. While it did the job, it looked like crap. So I ordered the correct parts from http://www.flatoutmotorcycles.com/

There was an o-ring around the base of the petcock and two rubber washers that go under the bolts. Numbers 16 and 18 here:

[JTsGS650]

Damn, I've got to learn to be quicker with my posts and not get up to get a cup of coffee in the middle!

[DimitriT]

Remove the petcock and inspect the area where the new o-ring is sealing. Make sure it is clean: no flaking/bubbling paint, no rust, nothing. If the paint is coming up around there, apply 400/600 grit metal sandpaper until its clean. Maybe spray some clear sealer over that.

[Sniper]

Alright, that's what I was thinking, there should be rubber washers under the the heads of the bolts holding the petcock to the tank (they are missing).
Thanks for the diagram guys, very helpful with comentary. I've looked at those darn things before and for some reason it didn't click about the washer for the bolts. I'll stop by the parts store on my way home and pick up a couple rubber washer, I'll let you know if that's all it is.
DimitriT - thanks for the ideas, that was the first thing I checked when I took the old petcock off, the o-ring was going bad and was no longer adheared to the petcock, so that was adding to the problem before I think because it leaks slower now than it did before.

[Sniper]

Ok, so put the new washers on, and it still leaks! I think I'm going to try some teflon tape (the stuff you generally use on pipes for water) around the bolt threads. I'm pretty sure the stuff is chemically inert and good to temps of about 500 degress, but just wondering if anyone has tried this before and had bad results, or works with the stuff and knows more about it?

[bwringer]

The teflon tape won't hurt anything, but it also won't help since it will only seal the threads.

You need a sealing washer under the bolt head. Personally, I use 1/4 inch black nylon washers from the hardware store with excellent results (on the petcock and on the carb float bowls). Rubber washers just warp and tear in my experience.

[DimitriT]

In my experience teflon tape dissolves in gas.
Maybe some kind of crush washer will work: brass or copper?

[Sniper]

Ok, had some gasket material laying around, so I cut four little squares (two for each bolt) and put those under a hard washer under the bolt heads along with the teflon tape on the threads (near the head of the bolt), and vuala.... no more leaking. Thanks guys!