[levviathor]

So I'm back. I'd been having troubles since my reserve has been clogged. I got fed up, drained the tank, and pulled it off. I poked around, but didn't see anything wrong so I reassembled it (should I have sprayed it with something?) and put it back on.

Well, now I have two problems: the reserve is still clogged, but now the petcock leaks gas (rapidly when petcock is ON and the engine is off, slowly while petcock is OFF). It's not feeding gas very well (either too much or too little), so the engine has been hard to start, a bit stutttery, prone to stall at idle, and needing a pretty heavy throttle.

It's a vacuum fed petcock, and I half suspect that that is the source of my problems. I'm about to go check the membrane for punctures of any kind.

So:
1. What did I reassemble wrong? And
2. How do I unblock the reserve feed?

 

[CX-Viking]

Did you connect the vacuum line? I know I forgot the first time and the bad diaphram let enough fuel through to confuse things.

My advice would be to buy a new non-vacuum petcock. At the very least it would eliminate that as a problem. They are $20 or less on ebay. I believe they are 18mm x 1mm

This one should work but others may know one for sure.

Honda ATV Motorcycle Fuel Tank Gas Petcock Valve Replacement 18mm x 1 0mm New | eBay

Good Luck

 

[SiriusBlackOp]

Personally, I would rebuild your current vacuum petcock. It's not hard and the blockage may be a result of the membrane falling apart. You will also be able to see more once you get the petcock apart.

The only reason I don't like a non-vacuum version is that if your carburetor floats stick after a ride and you leave the non-vacuum petcock on, then you will come back to find a full tank of gas has poured from the tank, through the petcock, into the float bowls and then through the float bowl overflows and out onto the ground. Not Cool!! The vacuum version obviously prevents this by automatically closing when the engine is not in use.

 

[SiriusBlackOp]

Rebuild kit:
Honda CX500 GL500 Petcock Rebuild Kit | eBay

 

[slashfan10]

Flea bay kit $15.00 most guys on this forum eliminate the vac. I'm rather fond of it. There is a a wiki link on this. Can't find it off hand, but easy to do. There is a few things that can go wrong. Make sure your o- ring on the bung to the tank is new. I purchased mine from the local hardware store.make sure the vac line is hooked up correctly, as per diagram on wiki, and make sure your floats are not sticky. That will cause a problem like you have described. I almost never turn off my petcock. If everything is working properly you shouldn't have to.

 

[levviathor]

Checking back in, good news!

I took the petcock apart. The membrane is still in great condition. Having carefully put it back together, I hooked it up to the carbs, set it to reserve, and blew 120psi compressed air through the gas line while cranking the engine for vacuum. Whatever was lodged in there sure ain't anymore. Everything runs well now in that department. I may start a thread asking about a few lingering issues elsewhere.