Evinrude 25hp slipping

I have a 25hp 1987 evinrude m

I have a 25hp 1987 evinrude motor on my pontoon and that is slipping when I give it gas. It keeps slipping until it reaches full/3/4 throttle and the its fine. Does anyone have any suggestions? The local boat shop said the lower unit is shot.

slipping or cavitating? you m

slipping or cavitating? you may have the motor mounted too high. Try a set of fins like a WHALE TAIL or similar brand to get a better supply of water to the prop.

It is a short shaft motor....

It is a short shaft motor.... If something was worn in the lower wouldn't it jump out of gear when it slips? I just need to back of the throttle and then give it power again.

" Where is the cavitation plat

" Where is the cavitation plate (the plate just above the prop) in relation to the keel (bottom of the boat at the transom)?

If anything was wrong within the lower unit, it wouldn't slip. It would either do nothing at all (no movement) or it would be jumping in and out of gear which would give you the sensation of hitting a object in the water... a clunking, jerking sensation.

You really haven't defined what you mean by "slipping". The term of "slipping" usually pertains to having the prop hub slip within the prop. If this was the case, the slippage would be worse at the higher rpms, not better.

Joe (30+ Years With OMC) "

How about contacting the manu

How about contacting the manufacturer of the boat. You may find that a long shaft motor will cure this problem.