QT50 stalling problem

Bruce Galbraith /

My QT50 starts on first or second kick,runs good but... after long full on running it will stall when you come to a stop. I replaced the carb and no joy! so I'm reaching out to people smarter than myself. Any help would be appreciated. Thanks

Re: QT50 stalling problem

Exactly how long is your 'full on run' ?

Re: QT50 stalling problem

Bruce Galbraith /

It usually happens after maybe 1/2 mile or more runs.

Re: QT50 stalling problem

Sounds like one of the electrical components .

Coil or pulse generator or CDI ???

Re: QT50 stalling problem

Make sure your base gasket to engine or head gasket isn't letting in air, or your carb to intake,intake to engine is not leaking air. Just small leaks can kill idle in certain conditions

Re: QT50 stalling problem

Louis Brunskill /

The coils crack on the QT often crack, look around the outer edge for cracks ~ electric leaks.

Re: QT50 stalling problem

Jack Rutherford /

possible solutions:

1 - turn up idle speed screw to increase idle (maybe your idle is set too low but that would probably manifest itself at start up as well);

2 - stock bike? if so, I doubt it's a main jet size issue. modified bike with bigger jet - maybe too big a jet so that it chokes itself out after full throttle run and then dropping to idle;

3 - or it could be the opposite - air leak causing it to fuel starve when switching from full throttle to idle.

Re: QT50 stalling problem

Verify you have proper fuel flow. Also when it dies pull the spark plug and check the spark. I too have seen more than a few qt charging coils go bad.

Re: QT50 stalling problem

What year? Try it without the gas cap on.(edited)

Re: QT50 stalling problem

Louis Brunskill /

The gas caps do have a cardboard spacer in them with 2 tiny holes to let air through. Cardboard can swell. Mine was pretty mushy. You take it apart with a rubber tip air blow gun.. wrap it in a rag so the lid doesn't go shooting across the shop... and blow in one of the holes.

Re: QT50 stalling problem

If its a 79 it's the charge coil if I were to bet.

Re: QT50 stalling problem

Jack Rutherford /

I think we lost Bruce but welcome back, Arlie.

Re: QT50 stalling problem

I see others are having similar issues. Me, Robbie, Bruce....

I'm sick of tearing this thing down and back together again.

*Fuel-I'm going to put my original carb back on. The clone carb did not seem to do anything.

*ELECTRICAL-Pretty sure my charge coil is shit. I am still running with the electrical system detached. I still have not figured out my electrical issue

*Air leaks-I have put spacers to clamp my air filter box shut cuz I still have a stock one.

Can someone please tell me how many holes are supposed to be in this thing? I got a big rectangular hole and a small one on the outside. It's pressed shut everywhere else.

I'm sure the neck of the damn thing isn't helping.

Does anybody know something I can just walk into O'Reilly or AutoZone to put on here? I read that people set a truck breather can work. What the hell is that in the first place?

Re: QT50 stalling problem

Jack Rutherford /

emgo makes a 28mm filter that you can pop on the carb

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