Petcock Rubbers - What Is The Secret?

[Muddy]

G'day Everyone

I keep having a recurring issue with petcock seals (both rubber and cork) swelling and blocking off the fuel flow. Ready for my fourth rebuild now and getting a bit sick of draining the fuel tank to rebuild the petcock. The last cork one I put in, I ran a drill bit thru after it swelled. This time I went away from the cork and tried a rubber unit. It made the petcock very hard to turn right from installation and now appears to have swollen and severely restricted fuel flow.

Does anyone have any tips to stop the cork or rubber swelling and stopping fuel flow or is the only real solution to go with the alternative "standard" fuel tap design as on a lot of newer motorcycles (often referred to here as the Harley-design)?

I'd really like to keep the original petcock but don't think I can take kindly to another rebuild. :-(

I've tried to but from the reputable dealers, but am still having problems - is this just me or a characteristic of the petcock and cork/rubbers?

I can't blame ethanol in the fuel as we can easily purchase 92 - 98 octane straight fuel at all our petrol stations here in Australia.

Any tips most welcome.

[rrietman]

I have had very good luck with the readily available kits. am running two bikes right now with rebuilds a couple years old with no trouble. also have done a couple more in the last month with no issues. certainly always stick with the cork packing, the rubber is junk. so no ethanol? suspect some other additive is what's hurting you locally.
Good luck
Randy

[DianneB]

I went through 4 different rebuild sets on my C77, all from different sources, and all of them swelled. I gave up and went with an after-market valve. The original is in the parts box for the next masochistic owner! ;)

[Wally Schauer]

rrietman- I would be curious to know where you got the carb shutoff kits, I, like others, have had no luck with the rubber parts not swelling. I have tried supposedly OEM kits from Honda and a couple of aftermarket ones. All of them swell up in regular ethenol gasolines. ( Yes, I know its possible to buy non-ethenol but it is not always convienent when riding.) Anyway the last kit I purchased I dropped the rubber parts in gasoline for a day and all the parts swelled up including the cork/rubber seal -though not as much as the other all rubber parts. Anyone who buys a kit would be wise to do this before installation, and as the parts do shrink back if you let them dry for a week or so, they should be returnable.
Like DianneB I gave up on the stock unit and machined an aluminum plate (also available commercially) and installed a modern Yamaha petcock with "Res. Off On".

[Wally Schauer]

rrietman- I would be curious to know where you got the carb shutoff kits, I, like others, have had no luck with the rubber parts not swelling. I have tried supposedly OEM kits from Honda and a couple of aftermarket ones. All of them swell up in regular ethenol gasolines. ( Yes, I know its possible to buy non-ethenol but it is not always convienent when riding.) Anyway the last kit I purchased I dropped the rubber parts in gasoline for a day and all the parts swelled up including the cork/rubber seal -though not as much as the other all rubber parts. Anyone who buys a kit would be wise to do this before installation, and as the parts do shrink back if you let them dry for a week or so, they should be returnable.
Like DianneB I gave up on the stock unit and machined an aluminum plate (also available commercially) and installed a modern Yamaha petcock with "Res. Off On".

[Muddy]

Thanks for your input everyone - I thought it was just me!

[G3]

I got mine off of eBay. "peanut8500" is the seller. I was or thought I was cursed with the leaking petcock syndrome, until I used this kit. No trouble whatsoever. Installed it in February this year, and all has been good.