Nathan_O,

I would be looking at the valves because if they are not seating properly your compression will be low and as you have said spluttering back through the carby, then it is pointing to the valves.

Check the valves before righting the motor off because they are not that expensive to replace and it is cheaper than spending over $1000 for a new motor.

Have a look and let us know if it is valves. cheers2

Regards,
[Linked Image]

Bruce


Please do not PM me asking for support. Post on the forums as it helps all members not just the individual.