78 johnson 25 hp runs great at low speed but winds out when giving it gas

[dano1215]

My Johnson runs great at low speed but as soon as I give it gas it just winds out.I marked the prop hub and it has not spun. Last year I put a new clutch dog in it and had the forward gear machined. The mechanic said I should get a few years out of it.Could the forward gear be my problem? Any input would be greatly apperciated. Thank you

 

[Tim Frank]

Winds out??

 

[kbait]

If the forward gear engages normally, and pushes the boat at idle, but increasing the throttle increases the rpm's but not boat speed, and you have no clunking sound.. spun prop.

You may have got 'lucky' on your marking test and the hub and prop stopped slipping at the original mark?

Also, if you can barely get over idle when the engine winds up, try to spin the prop on the shaft by hand (in gear, engine off, plug wires removed). You can hold the flywheel to provide resistance for this test..

Good luck!