Starts On 2 Cylinders Restart 3 Cylinders??

Bassy · Aug 29, 2020

Hi my mate has a 96 sprint 900cc, when he starts it takes a little bit of cracking over and when it does its only running on 2 cylinders, he then turns off and starts again and starts effortlessly on all 3 cylinders.
Battery has been checked, has good spark
Anyone out there got any clues please.
Concerned he might bugger starter clutch if he aint careful.

Callumity · Aug 29, 2020

The joys of advancing old age.....

Sounds like dirt in carb primary circuit or a coil on its way out. The cold exhaust header will betray the guilty cylinder.

stevethegoolie · Aug 29, 2020

Give it a goodly slug of Redex or other fuel system cleaner which will, hopefully, deal with muck etc in the carb.

Bassy · Aug 30, 2020

I was thinking fuel and that may be fuel lines may be breaking down internally. Was going to replace fuel lines and clean cars and re balance see if that works. If not go onto ignition coils.

Cheers guys

Wire-Wheels · Aug 31, 2020

More likely an ignition problem. If it were dirt in a carburetor, it probably would not change when you restarted it. Could be as simple as a weak spark plug. When it gets a little heat it it it starts to fire. My experience with weak coils has mostly been them misfiring once the engine gets warm. ...J.D.

AFTERTHOUGHT: You might also get it's valves adjusted.