787 Crank/Cylinder Rust

[Themist456]

Hello everyone,
Just got a 96 XP parts ski that the hull blew up on (leaking gas and ignited). Been pulling the parts out the last few days.

I took the motor out and was unable to turn it over by hand past a certain point. Upon inspection there was very minor rust in the cylinder. I sprayed both with fogging oil and most of the rust actually dissappeared just from that. Did a compression test and both cylinders are even at 165 (probably high from fogging oil) Looking in from the intake I do not see rust in the crank at all but my fogging oil is turning brown after cranking it with it in there. Does it just do that? Or is that from rust? I am fairly certain that the rust formed from sitting with water in the exhuast for around a year. Would crank rust from water sitting in the exhuast? Or would it mostly affect cylinders? After fogging it, I am able to move it 360 with just my hand and spark plugs out.

 

[etemplet]

I'd pull the rotary valve and flush the engine what gas while turning the crank shaft. I'd do that a few times. Then put some injection oil in there and lubricate everything. Rotate the hell out of the crank and flush again. I've done this to a couple of engines but I had the cylinders off. People would be surprised at what these engines can endure. Soon as you build and run an engine the failure process begins. It can be prolonged with good maintenance. Good Luck !!