Pro50LF

[tal]

I rebuilt my 89 50hp yamaha a little over a year ago. It's just now getting to the point where I don't have to run extra oil for the break-in. I believe the reason the engine burned up is due to failure of the 3rd cylinder getting oil. I have redone the lines and check valves from the oil pump since then, but I just don't trust the system as a whole. It leaks a hell of a lot of oil when it sits, and the bottom cylinder gets filled with about a half cup of oil. I had to remove the plug and turn the engine over manually to push all the oil out. I would like to know why or how it leaks oil into that cylinder, but I would like more to know how to properly disconnect all of it and do it the old fashioned way. If someone could be so kind to fill me in on how to do this.<br /><br />Search doesn't "search" before anything since the crash. Thanks.

 

[pine island fred]

Re: Pro50LF

Been awhile since I did mine, same engine. Remove the oil pump and remove the copper drive gear driven by the crank. Make up a cover plate for the pump mount. Disconnect the hoses and cap the fittings at the base of the carbs. Disconnect the oil tank low level warning harness at the top of the tank. I removed my tank, cut the top oil fill cap flange off and secured the flange to the cowling. <br /> Hope your damage did not involve the one piece connecting rod. My damage was to the nbr 3 connecting rod journal. regards fred

 

[tal]

Re: Pro50LF

Thanks for the reply Fred. I have already done everything that you said, except I managed to break off the fuel pump inlet for the gas line so a new one of those is on the way. It was a bit brittle and I suppose it won't hurt to have a new fuel pump anyhow. I disconnected the what I think is the oil sensor. I assume it is the wires with a blue sleeve on them (these are the only wires coming out of the tank) that ran under the engine and hooked into a round plastic connector by the throttle cables. The rods checked out to be ok and the damage was done to the 3rd cylinder. The piston was so shot it had O psi when I compression tested it.<br /><br />Thanks<br /><br />Ryan