simple shutoff valve quest.

Hey guys, here's a stupid question (I'm new with mopeds), is it better to have the shutoff valve on (in run position) when the moped is not in use and sitting in the garage or should I keep it in the off position? I heard froma guy that I shouldn't turn it off and on because rust may get into the tank. Thanks in advance for any replies.


Re: simple shutoff valve quest.

That advice seems totally bogus to me. How would rust enter the tank as a result of turning the fuel on & off? Rust in the fuel system originates in the tank, not in the petcock, carb, lines etc - none of those parts can rust internally.

The fuel should be 'off' when parked; that's why it's there. All it takes is a slightly marginal inlet needle/seat, and the gas from the tank can flood the carb, get all over the bike & floor, and possibly even fill up the crankcase with fuel.

Re: simple shutoff valve quest.

Thanks, that answers my question. But I realized I phrased it incorrectly and I wasn't really specific enough. I think what the guy said was that if I turn the valve off and on then if there is any rust in the tank it can fall into the opening of the valve somehow. That may seem to make a little more sense but I didn't think he was right and you helped me confirm that. Thanks.

Re: simple shutoff valve quest.

Ok, there is some sense to that, then.

The fuel shutoff (petcock) comes with a little mesh filter on it. This is to prevent rust particles from the tank entering the valve, and causing damage to the valve itself.

If the screen is intact, then you should be OK. If not, then I'd think about a new valve - since I've never seen replacement screens.

Re: simple shutoff valve quest.

How do I find the mesh filter. Is it obvious or would I have to take the valve apart? When I take the shutoff valve off the bike I can't really see a filter. Thanks for the previous help, I appreciate it.

Re: simple shutoff valve quest.

The filter is a part of the valve itself. If you remove the valve from the tank, the filter (if it's there) comes out with it.

But here's the thing.. if the filter is not there, there isn't much you can do about it, other than buy a new fuel valve. Just run with what you have, and if the valve ever fails, replace it.

And I still think you should turn the fuel off when it's parked a long time.

Re: simple shutoff valve quest.

George Smith /

yeah filling a crankcase with gas sucks...i mean 1 puch...filled crankcase.....2 fire extinquishers and you have your self a bad day

Re: simple shutoff valve quest.

Ok, thanks for the advice everyone, I plan on keeping the shutoff valve closed when I am not using the moped. I do appreciate the help that was given.

Re: simple shutoff valve quest.

Brian Mikami /

Here's some valves. My Maxi has the #6 valve. Tiny screen filter on top of the main tube and one tucked into the reserve inlet (by nut). These will screen out most tank rust, but too much rust can clog it too. I also run an external inline filter to the carb.

« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account