15 hp jumping while in forward

My buddy's 15 horse Evinrude, model #15404 S, has started jumping occasionally when running in forward. When the skip happens, it sort of feels like the motor is hitting a log. This seems to be happening more and more often. His repair guy told him that the repair would be very expensive and it might be time to throw the motor away. (I told him to throw in into my yard.) Its a good running motor otherwise. Is this a bad gear in the lower unit? If so, is that lower unit interchangable with others? I don't have a book on this motor, but according to what I'm finding online, it seems that the lower unit is the same for a 9.9 up to the 15, but I'm not even certain of what year this one is. Any help is appreciated.<br />_Tom

Re: 15 hp jumping while in forward

Tom-<br />I have a 35 Evinrude that is doing the same thing. Mine got so bad I had to paddle back to the landing. I will be looking for the answer to your question as well!!!

Re: 15 hp jumping while in forward

Hopefully, since it's a 1974 model, you could match up a lower unit fairly easily. Barring that, your clutch dog is probably shot in the lower unit. If you want to try and repair it, I would not run it anymore, as you may be able to salvage the gears if not rounded off too bad. It will only get worse the more it is run. Grab yourself a Manual and remove the lower unit and have a look at things. Couldn't hurt at this point, as you are going to have to fix it or replace it. E-Bay usually has these lower units on there quite often. I don't believe there was any difference in the 9.9 and 15 lower unit of the same or close years. Others will know. Parts are still available for that motor at several places. All is not lost...<br /><br />For Example:<br /><br /> web page<br /><br />There are two more on there now, also: Might bookmark this site for future reference, They come up all the time...<br /><br /> web page

Re: 15 hp jumping while in forward

Before you do much else, check the prop. This sounds like the bushing has failed. You can check it by taking it off and scribing a mark on each side of the rubber bushing, then check again after running to see if there was slippage.

Re: 15 hp jumping while in forward

Thanks for the fast replies. I was already watching one of the lower units on ebay, but I've added two more to the watch list now. We're talking about running up to Carlyle lake on Saturday. We'll be using the 50 horse Merc there, but I could try the check for the bushing then. I'll have to get a manual that covers the 74. The one I have is for real oldies ... for getting my 1958 35hp super seahorse going again. I have a feeling I'll be asking more questions in the near future. lol<br />Thanks again<br />_Tom

Re: 15 hp jumping while in forward

I'll have to agree with Rick. If the bushing was spun, you would get a high rev in rpm's but you wouldn't pick up any speed. The "hitting a log" term kinda says it all.

Re: 15 hp jumping while in forward

Justwannafish<br /><br />Not on the subject, but we were at Carlyle 2 weeks ago and the water was up 6 feet and made boating so much better. It was like a different lake. Lots of places you could go that you couldn't before the water rose. Went to Mark Twain this last weekend and the same thing. Plus, oddly enough, it was super clear and clean...

Re: 15 hp jumping while in forward

Up six feet? ... That is good for boating but I bet the fishing is slow. The Kaskaskia and the Mississippi are way up, so I guess they'll be holding onto that high water for a while.<br />Tom

Re: 15 hp jumping while in forward

I was just thinking ... If the problem is a spun bushing, is there an inexpensive and "no special tools" repair for that, or should I still be looking for a lower unit? I'm the type of person who figures out how to repair just about anything. Just ask my wife. Her clothes dryer was 15 years old when a friend gave it to her ... about 20 years ago lol.<br />Tom

Re: 15 hp jumping while in forward

Tom....just pull the prop off and take it to a prop shop or dealer that can get it done and tell them you want it rehubbed. Shouldn't cost much.