Automatic Petcock Rebuild

Greetings All,
Here's a tip that may help some of you out. Recently I had a need to do some service on my Automatic Petcock(No 2 Cylinder fouling out with gas).To be precise, it had a ruptured diaphragm. Well, I went to the local Kaw dealer...and they told me that the individual parts were no longer available, but they would sell me a new petcock for $133.00! Of course I was enraged about this sort of extortion-so I resolved to do a little research on the internet. Yes there are some aftermarket kits with the rebuild parts, but they range in price from $34.99 - $69.00. I still felt that there must be a better way to go on this issue, so I went down to the local Autozone to see if they had some gasoline resistant sheet rubber. While there I found a "HELP"(Dorman Products)kit that has a perfect diaphragm in it for my petcock. It cost me $4.21 including tax! The kit number is 90082 and originally intended to be a replacement for old style Ford carbuerator accelerator pumps. I had to do a little careful drilling on both the old diaphragm assembly, and the new kit. To get to the point, I had to carefully dissassemble both of them, and tap threads into the original "piston" that seals off the fuel flow when there is no vacuum to pull it back against the spring in the valve assy. Then used a stainless steel screw to re-assemble...and presto, a fixed petcock for $4.21, and about an hour of labor! I have since bought another "HELP" kit and now have a spare diaphragm stored flat in my tool kit for any on the road repairs in the future. I realize that I'm not being as detailed in this as I could be, but figure that any of you with the interest to look at this post probably have enough mechanical apptitude to do a nice job of it yourselves.

Also, as a side note about the fuel topic...My local Carquest had a fuel resistant O-Ring kit (behind the counter) that I used to replace the needle valve cartridge seals in my Mikuni 34CV carbs!

Now that's just plain *cool*.

I got introduced to how much Kaw likes to charge for a silly little diaphram (eeeek!) kit a few years ago myself. I paid around $30 bucks as I recall.

Likely as not, I won't need to mess with it for another 8 or 10 years - the original managed to hold out for 25 - but that's a good one to have in the hip pocket.

Thanks...

Fuel resistant o-rings are made of Nitrile. Harbor Freight sells both metric and SAE "kits" which sell for under $5 a kit when on sale. I routinely buy the metric kits for use in my business as I use MANY of the smaller metric sizes.

Thanks for the feedback.

I joined up here just to be able to post that tip.

I just feel that there's too much ripping off going on in the parts market for our bikes. Also that the original design of those automatic petcocks was intended to generate a future rip-off situation. I would've used a double O-ring sealed piston, and cylinder design.

Hey wiredgeorge,
Thanks for the info. I'm especially happy to see that they have the metric sizes because they are hard to find, and I'll feel better about having the exact sizes I need in those carbs of mine. I was originally trying to find the "Viton" O-rings locally as they're rated higher for the chemical, and temperature tolerances. Now I think I'm gonna go over to the Harbor Freight site, and see what they have. Thanks again.

wiredgeorge wrote:

Fuel resistant o-rings are made of Nitrile. Harbor Freight sells both metric and SAE "kits" which sell for under $5 a kit when on sale. I routinely buy the metric kits for use in my business as I use MANY of the smaller metric sizes.

Dude, I just put this kit on my list. Not an hour before reading your post. $3.99 in the latest flyer. Prices good to May 30. Add does not show metric but both stock numbers are listed. Also on list from HF: Dog yo-yo $3.99, cotter pin kit $2.99, 2 x 10" buffer pads $2.99, respirator $20(I'm dry sawing tile next week as part of bath demolition).

Techaddict- Thanks for tip. Always good to find something like this. Have a suzuki gs petcock in need of rebuild right now!

-Duck

Post edited by: Duck, at: 2006/05/17 14:47

The petcock from a '78 GS 750 bolts perfectly into place.