1984 Johnson 15HP Won’t Change From Neutral

[paytonboat]

My 1984 Johnson 15HP has been running and the gear level can be pushed from forward to reverse as normal but the motor doesn’t go forward any faster than the neutral speed. Any advice on what’s wrong with it or how to fix?

 

[vics]

Not entirely clear what is happening / not happening from your post

If the engine revs increase when the throttle is opened but the boat speed does not increase above its speed at idle it is probably because the prop is spun .

Test by marking the end of the shaft ( or use the head of the cotter pin as reference )and marking the prop hub in line with it. Try the boat
then inspect the marks . If they are no longer in line with each other the prop hub is spun

 

[racerone]

Might be running on 1 cylinder.-----Post compression test results.----And does spark jump a gap of 3/8" ( 1 cm ) on both leads.

 

[flyingscott]

are you turning the throttle