1971 Evinrude 25 hp seahorse disengages at half or higher throttle

[tomboarderns]

MY 1971 Evinrude 25 hp seahorse tiller motor will run fine at lower speeds in forward and reverse. As soon as I open the throttle to half or wide open it seems like it goes into neutral and the prop stops spinning, the engine revs really high. As soon as I back the throttle back down it engages again.

Just wondering what your ideas are. From what I could tell after searching that it could be the clutch collar? not sure if that was the name.

Also, if that is what it is, how hard is it to change out? Any tips or hints. I have not worked on this motor yet, bought it 6 months ago and this is the first issue.

Any idea on what caused this or just parts that wear out? Just want to make sure Im not doing anything wrong.

Thanks

 

[AlTn]

Re: 1971 Evinrude 25 hp seahorse disengages at half or higher throttle

if you're not experiencing a thud as if you've hit something underwater, more than likely you've got a prop hub that's spun..make a mark across the outer edge of the prop down to the prop shaft and run the boat until it revs up < feels like it goes into neutral >..if the mark on the prop and hub don't line up, then the prop and hub have slipped in relation to each other...a thud or violent kick indicates something internal to the gearbox

 

[kfa4303]

Re: 1971 Evinrude 25 hp seahorse disengages at half or higher throttle

+1. Over rev usually indicates a spun hub, but if it feels like you're hitting something and it's popping in/out of gear, then you probably have a worn clutch dog in which case you'll need to open the gear case and visually inspect it.