Timing Johnson 120 1993

[michaelhedges]

Does anyone know the procedure for adjusting the timing on this motor? Can any new timing light work?
The motor started losing HP on the top end and recently has started to miss badly at idle. Changed plugs and carbs carbs. Turned spark advance screw a known amount and the idle issue went away. There was no locking nut on the screw (should there be one) I am thinking timing screw has slowing been turning. What yall ya'll think?

Thanks,

Michael

 

[MarkV_Deep6]

Re: Timing Johnson 120 1993

Yes there should be a lock nut. Are you sure this was the timeing screw you adjusted? Check out frequently asked questions for timeing . Do you have a manual to reference?

 

[michaelhedges]

Re: Timing Johnson 120 1993

Yes there should be a lock nut. Are you sure this was the timeing screw you adjusted? Check out frequently asked questions for timeing . Do you have a manual to reference?

 

[michaelhedges]

Re: Timing Johnson 120 1993

Im' sure this is the spark timing screw. Looks like there is a spring and nut on it to hold it in place, but the screw turns very easily. Just checked compression and 130 to 135 on all cylinders should be good i would think. The fly wheel is marked 8 degrees btdc and 18 atdc. I will be checking the manual soon, it is at my fathers house. I would like to add that in 13yrs, this motor has only had one carb cleaning job and regular spark plug changes except,( for lower unit oil it gets changed once a year at least) Would there be anything else to check if this checks out OK.