Engine cutting out at high rpm By dozer187 (Read 7,175 times)

[dozer187]

What u saw in the vid is what it does with every needle from 85 to 95

[Alleyoop]

If you talking about that big gold cap , No that is just a cover for the screw that holds the throttle wheel from the other side and the butterfly inside.



Do what I mentioned rev it up and then when it acts up with the rpms going up and down BACK OFF THE THROTTLE 1/8 to 1/4 of an INCH AND HOLD IT and see what the motor does. That will tell us what it needs,
More fuel or less fuel
Alleyoop

[Alleyoop]

Did you ever take the top cover off and mess with the needle and diapghram? I noticed it had a little trouble revving up even some where in the mid range. It could be it is leaking a little by the cover over the diaphgram and causing the needle to go up and down.
Alleyoop

[Alleyoop]

I now what it is doing but just do the TRICK OF THE TRADE to find out what the motor needs.
You may need a 98 or 100 main jet we don't know but doing what I said will tell us if it needs a bigger main jet.
It will take you 1 minute to find out
Alleyoop

[dozer187]

Diaphragm was never touched, 85-90 are to lean.91 and 92 still not running right 93 is to rich...this gy6 makes me miss my old 2 strokes so much...at about half throttle itll rev to almost 8...anywhere past it does that bogging stutter crap...im gona try my 98 jet for craps and giggles on thurs when im off

[Alleyoop]

The problem is all fuel delivery and maybe the 98 is what is needs cause. The up and down is a LEAN condition so it needs a 98 or a 100.
Alleyoop

[dozer187]

well unfortunately its been raining most of the day so i didnt have a chance to try the 98 jet, but i noticed when i was lookin over the bike that my exhaust gasket is missing, could that be causing a problem as well?

[Alleyoop]

Missing a gasket WHERE, where it attachs to the motor? Or just where it attachs to the muffler?
If where it attachs to the motor it would most likely cause backfiring. If where it attachs to the muffler no just noiser.
Alleyoop

[dozer187]

at the motor, i ordered another one, an actual gasket not the terrible stock ring type, should be here saturday.

[Alleyoop]

That should help it from running lean

[dozer187]

Well i have another issue, my friend pulled the intake manifold off my bike instead of just the carb like i asked himm to and doesnt remember which way the insulator goes and if the gasket goes between the insulator and engine or between the insulator and manifold

[Alleyoop]

The gasket goes first then the spacer, the intake manifold has a rubber gasket that seals against the spacer.
Alleyoop

[dozer187]

Tried the 98 and 100 jets....to rich..i cannot find a jet that works right, last time this thing ran perfectly was with stock airbox and exhaust,with the filters out and cover off the airbox... thats the only time it revved out perfectly

[Alleyoop]

Well put the stock air box back on, I know many 50s had trouble with them off and they wound up putting the air box back on.
Alleyoop

[dozer187]

with the stock airbox i had to have the cover off and the filters out for it to run right, im trying to figure out how i can run the stock box with the cone filter inplace of the stock filter elements, otherwise im in the same boat now with trying to get it to run right.