1985 G1 Runs fine low speed , high speed run for a mile then fall on its face

[mike77z]

Well a customer dropped this cart off to me in boxes last week and i got it moving and he took it home on Friday. Today he brought it back to me complaining of the mentioned problems.


As I'm a heavy equipment mechanic i have limited experience with these carts. I removed and cleaned the carb blew out all passages etc , checked needle and seat, float level , fuel flow from the pump , oil pump , crank seals ( with the rudimentary carb spray on the seals ) , Electrical seems all good ( noticed in another post someone having the same problem lost a electrical connection to the mag ) Needle is 1.5 turns out off the seat. New plug and its not smoking much compression is 125

Governor is still hooked up but the linkage to the exhaust valve is gone , going to check to make sure its not causing the issue as it is just flapping in the breeze. I'll remove the butterflies tomorrow if they are still there.

Thanks Mike

PS Any help is appreciated as hes hoping to take it home on friday again for the weekend

[GMB74]

If the exhaust valve is free to close off the exhaust whenever it wants, that could be your problem. It is meant to restrict the exhaust flow at low speeds for smoother running, but if it shuts at high speeds it will choke out the engine. Wire it wide open or remove it and weld up the holes.
A plugged muffler is another possibility. Maybe a mouse nest or nuts floating around in there? I have seen that before.

[sho305]

They can plug up with carbon/oil. I had one I had to stick a rod up the outlet and crusty stuff fell out, then it ran fine. Could also be an ignition issue like a coil getting hot...or it is just getting hot from exhaust problem. Yeah valve needs to be open and is not really needed if you want to remove it.

[mike77z]

Ill have the unit back this week and give that a shot , its lead a hard life since it left the course

Thanks. Mike