1962 Johnson 28HP RX-10 3000 RPM max

[bilge22]

My RX10 has fresh rings. and seals. and carb rebuilt, and blah, blah, blah. It can not get to full RPMs. I've tried adjustment to the slow and main needles. I also tinkered with the linkage between the carb and timing advance. Slow speed runs great.

Any ideas?

 

[bilge22]

Have you checked to verify that's it's running on both cylinders?

 

[bilge22]

Oh, good idea. I will do that.

 

[bilge22]

OK, you were correct! The lower plug is not firing. New coil on order.

Thanks