1963 28hp Johnson - Backfire

[claytonfoster83]

I am looking for input as to why my engine is backfiring. This occurs at idle and full throttle, however more frequently at higher rpm's. There is not a steady time spacing between the backfires. The motor sounds good and runs well at idle and full throttle with exception of the backfire. The model is RX-11. Thanks in advance for the input.

 

[F_R]

Re: 1963 28hp Johnson - Backfire

Are you sure it is backfiring? Could it possibly be jumping or bumping as if you struck an underwater object? That would be a clutch dog and gears shift problem where it is jumping out of gear, rotating half a revolution and slamming back into gear. Extremely common.

 

[claytonfoster83]

Re: 1963 28hp Johnson - Backfire

Thanks for the input. I made a couple adjustments to it over the weekend on the gear shift and resolved all the issues.