1981 Evinrude 115hp slipping

[Nick5500]

I have a 1981 Evinrude 115 took the boat out and was going good untill I gave it full throttle then revved up and barley moved took it home and changed the prop and there was no difference (bought a new one) it will rev up and then catch and will move ok but also lost ten mph in my top end speed I have rebuilt my lower unit and just yesterday I took it back about everything is good I am lost sorry for the long post first time on here thank you for any help

 

[racerone]

Measure transom height.---Post it here.------Sounds like motor is mounted too high.

 

[Nick5500]

Even if it has been running alright before it could do it out of the blue?

 

[fdrgator]

Even if it has been running alright before it could do it out of the blue?

You have us in guessing mode. So, a guess. Perhaps it did have a slipping prop hub on a prop that was suitable for a high transom mounting. Then you replaced it with a prop that is less suitable for a high transom mounting. Like I said, a guess. Nothing to lose by checking the height.

 

[Nick5500]

Thank you