35hp runs great up to 1/2 throttle then winds out producing no more power

[14GR8BOATING]

I have a Evenrude 1958 35hp. I had it running great up to about 1/2 throttle, then when I give it more throttle it winds out but doesn't go any faster. Kind of like a clutch that is slipping. Lower end problems? I greatly appreciate any input. I have manual for the motor on the way. <br />Thanks!

 

[ob]

Re: 35hp runs great up to 1/2 throttle then winds out producing no more power

Sounds like a spun prop hub.I know it's pin drive but not sure about the hub.Another thing that could cause your issue is prop not getting posstive bite in water and slipping.Has the motor performed well recently as mounted?If so ,then prop ventilation is not likely the problem.

 

[MCM]

Re: 35hp runs great up to 1/2 throttle then winds out producing no more power

That would be my first impression ob.<br /><br />You might wan't to pull the prop and have a look at the shear pin.

 

[Silvertip]

Re: 35hp runs great up to 1/2 throttle then winds out producing no more power

Check the position of the anti-ventilation plate in relation to the bottom of the boat. If it is more than an inch above the bottom you may be experiencing blow-out where the prop loses its bite just before getting on plane. You may have a short shaft engine (15-inch) on a boat that requires a long shaft (20-inch).