crankshaft play

[rooster1]

i just bought a used boat with a 81 model 35 hp evinrude i got it to run by squirting gas in carb but i noticed play in flywheel so i removed it and its in the crankshaft what do i need to do?

 

[emdsapmgr]

Re: crankshaft play

My 79 had the same problem. These engines did have a common problem with the upper crank bearing. They will "loosen" up and the crank will move in an oribital motion, destroying the upper crank seal and causing a lot of noise. Also may be hard starting due to the loss of crankcase compression. My bearing never destroyed itself, but was really loose. You will need to replace the upper bearing and the seal. I had mine down for overhaul when I found the problem, but I think you must split the case to replace the bearing.

 

[rooster1]

Re: crankshaft play

thanks for the reply i work at a small engine repair shop and have built some small engines do you think i could do this one? my wife says i can lol what is involved in taking of the lower half from the power head?

 

[emdsapmgr]

Re: crankshaft play

If you have worked on 2 stroke engines, you are half way there. I would get a service manual explicitly for your engine and follow the procedures. You can get originals from ken cook in Milwaukee. Kencook.com. You can look at all the parts diagrams on Bombardier's website: epc.brp.com. You can decide how much other work you want to do when you see the internals.

 

[BoatBuoy]

Re: crankshaft play

emdsapmgr, was this a problem with a range of models or just the '81's.

EDIT: I re-read the thread and I think I've got my answer. The reason I'm asking is that I have a '77 35hp and wondered whether I should watch for this or not.

 

[emdsapmgr]

Re: crankshaft play

The loosened bearing was a small problem through a number of years-through 84. They all use the same upper bearing 386481. The only symptom that I was aware of was that the engine seemed to have a knock at idle. At high speed, the knocking noise got lost in all of the rest of the engine/wind noise. My 79 35 spent all it's life on a pontoon, and did not have a lot of hours.

 

[F_R]

Re: crankshaft play

Whew!!! emdsapmgr, you got me worried there for a minute. I had not heard of any problems with that bearing and have one of those motors (1984). So I just went out and checked it for looseness. Snug as a bug, as they say. I bought this motor new and have too many hours on it to count. Runs great.

Rooster, I am sure that working in a small engine shop as you do, you know that if a roller bearing goes bad, so does the shaft that it rides on. That would mean the crankshaft in this case. Also, since the crank is supported by 3 bearings, it is hard to imagine it flopping around like you describe from only one bad bearing. So, how are the others doing? Just my 2 cents. But as I said, I was not aware of any inherant problem. Let us know what you find in there. I suspect water intrusion was the cause????