1969 Evinrude 55hp sputtering at WOT

" Have a 1969 Evinrude 55hp.

" Have a 1969 Evinrude 55hp. Motor seems to run fine out of water, can push to WOT with no problem. When motor is in water, runs fine at idle and with some throttle but at WOT, seems to sputter and clunk along if I drop throttle again to idle runs fine. Fly wheel nut keeps coming loose (do I need to use lock tight), notch on rotor keeps breaking off and I've torn up one fly wheel key. On third rotor now. Was thinking it was gear related, noticed gear case could use some more oil and thought maybe there wasn't enough to keep clutch dog in gear, added more. Going to take it out again and if it still clunks along ,next step was to check the clutch dog. Any other ideas, I'm tired of buying new rotors. "

" Motors will usually run fine

" Motors will usually run fine out of the water (no load) it should not be a surprise , nor a trouble shooting method.The shift system is spring loaded to go in forward and the amount of oil in the unit has no affect on that function.The fly wheel nut comes loose, may be a result of not using the factory key , not torquing to the correct amount.Breaking the rotors is strange since there is no load to turn that rotor. Do a compression test and post your results.Are the points set at 0.010" and is the rotor, vent housing clean? "

"Frank..... If you've shea

"Frank..... If you've sheared even one flywheel key, the tapers of the crankshaft and of the flywheel are damaged. Those tapers will require reworking to get rid of the obvious defects.

The flywheel key is OMC #307480. If you're using anything else, you will have problems. The straight side of the flywheel key is to be aligned on the crankshaft in a "vertical" position. If you align it with the C/S taper, that will create a problem also.

There should be a wave washer sitting on top of the rotor. If it isn't there, the rotor will be allowed to wobble.

The flywheel nut, (with the tapers mentioned above in perfect condition), must be torqued to 105 foot pounds. Anything less and the nut will come loose, the flywheel will ride up, and the rotor will brreak due to being allowed to rise.

Joe (30+ Years With OMC)"

" Got two keys from a shop, wa

" Got two keys from a shop, was told they were for this motor, key does not fit snug in slots though, should it?

By tapers do you mean the slots the key fits into? They look fine, however I do see on the inside of the fly wheel what looks like weld marks? Thinking I may need a new fly wheel as it may not being fitting all the way down, do you have a part number/cost. Also with last rotor ordered a new wave washer as well, have yet to install it. "

"Frank..... Taper pertains to

"Frank..... Taper pertains to the tapered angle of the top of the crankshaft and the inside portion of the flywheel that corresponds to that taper.

That damage that looks like a weld mark is exactly what I'm talking about. That damage will need to be filed so that the flywheel sits perfectly on the crankshaft, and of course, you'll need to do some filing on the crankshaft also.

I can't get at my books right now as the alarm is set. Describe the flywheel to me, what numbers are on it etc. When I have that info, I'll see what I may have in stock.

Joe "

" Joe, filed down the inside o

" Joe, filed down the inside of the flywheel and so far engine is running very well, distributor cap hasn't broken again, and I can't hear it spinning around. But, now my water pump is not discharging water, I suspect that some dirt got into the engine from the tub it was running in and is clogging it up. Next step is to remove gear cassing and clean up water intakes etc. Any pointers before I start? "