Slipping out of gear

[rdeloach27]

OK guys, I have a 1976 15hp Johnson that I am having a bit of trouble with. I put it into the water and get it running with no problem. Idles fine...... I let it warm up and then put it into gear, all fine also. I give it gas and it seems to rev up fine and the boat starts to move. Just before the boat trys to plain, the seems to slips or comes out of gear. It only happens when I give it full gas. It will putt around just fine. I stoped and put it in nuetral a few time and start up again. Same thing each time. I think it is the lower unit. So I take it home and take the lower unit off to check some things out. I drained the oil with no sign of metal filings in the oil..... But to make sure I put my magnet through the oil with nothing. Then I looked at the splines on the shaft. It looks new still. I looked the whole lower unit over with out taking the guts out with no problems noted.

Please can anyone help.

Rex

 

[tx1961whaler]

Re: Slipping out of gear

If it bangs and feels like you hit a log, then it may be the clutch dog/forward gear in the lower unit.
If it just revs up, but doesn't go forward fast, but goes fine at low speed, then it is a spun propeller hub.

 

[rdeloach27]

Re: Slipping out of gear

It sounds like the spun prop hub as you discribe it. What id the hub and How do you fix that? It will go slow but when i put the gas to it, it will slip.

 

[Daviet]

Re: Slipping out of gear

The prop needs a new hub, not something you can do yourself. The prop needs to be rebuilt.

 

[tx1961whaler]

Re: Slipping out of gear

It sounds like the spun prop hub as you discribe it. What id the hub and How do you fix that? It will go slow but when i put the gas to it, it will slip.

A propeller shop can fix it easily. The prop is actually two pieces pressed together with a thin rubber bushing between the two. The rubber deteriorates over time, or lets loose after hitting something.

 

[rdeloach27]

Re: Slipping out of gear

Thank you very much, I was worried I need a new lower unit! I think I may buy a new prop because this one is the original prop. Thank you, thank you, thank you.......