Probably not related,... but, the test is valid, and easy... No harm in checking.   Do the test
Then,.. you'll know... ...

Hi guys! If you had a conversation about the petcockl , here's a question.
I am sometimes at a speed of 70-80 mph on the move stalls the engine. in other modes, this is not happening. When you try to start it I through the transparent fuel filter see that fuel was flowing to the carburetor. so until there was no fuel. This happens periodically. What could be wrong?
p.s. in the petcock I installed a new membrane from the repair kit. the carburetor is clean. the needle valve is in good condition. vacuum line it seems normal.

Vacuum drops as throttle approaches Wide Open, A stiff diaphragm may not allow full fuel delivery when it is most needed.
If youll run it till it starts to falter & kill it while youre rolling, you can pull over & open the carb bowl drain , catch it, & see whats in the bowl,
Close it off,, put it on prime, give it some time to fill up, put it back on "On", then drain & catch it again & see if theres a difference..

& certainly, do what the Rowboat says,,

The cost of oil versus the cost of an engine? Id drain it,,& then Id take a rag & dip in it & try to light it, If the rag lites right up.,.theres gas in it,
& DO be careful..

I have does not work when. Yes, I suppose so: fuel thingy does not supply enough fuel into the carburetor at full throttle. diaphragm and o-rings in the valve is new. at that time I still can do?
p.s. even noticed that this happens when the fuel in the tank about half or less.

wambr wrote on 06/25/12 at 10:22:32:




Making sure there are no vacuum leaks in the vacuum tubing would be easy,, slap a new piece of vacuum tubing on it.
Do what Serowbot says, he has a complete test for the petcock,

You can do all the tests,  and every now and then keep doing them.  Or just change it out to a Raptor petcock.  It's simple to do flows alittle better and you will never have the vacuum issues with it. Plus you will have a true off/on petcock.

R.F.