Engine wont turn

[louisiana redneck]

I have a 1993 yamaha 200 v6, 2 stroke. Yesterday i ran out of engine oil while running down the bayou, my sensor didnt sound, the temp. indicators didnt sound or light up either. I can turn the flywheel (in nuetral) by hand to a certain spot then it stops. I know its probably something serious but im willing to try and fix it myself. i am going outside right now and start messing with it. I will appreciate all replies, thanks.

 

[Scout Sport Fish]

Re: Engine wont turn

What happens when you try to crank it?

 

[louisiana redneck]

Re: Engine wont turn

The same as by hand. i dug into it today (the last day of my vacation) and found the top piston had aluminum pieces jamming it from making the natural cycle. With the cover off and pieces gone, it will turn freely 360'.
Now i will have to get a repair manual and try to figure out whats next. I am hoping that the cylinder has a sleeve that can be removed and i can install a new one in its place because i dont want to have to bore it out. The manual should also give me specs so i can measure the piston. Do i replace all the piston rings while im in there? I checked compression by feel at spark plug and all felt good. I do know the other 2 cylinders looked good after i removed the cover.

 

[Scout Sport Fish]

Re: Engine wont turn

Hmmm, maybe a piston ring broke free? Or maybe valve failed.

 

[Ray Neudecker]

Re: Engine wont turn

No valves in a two cycle. Sounds more like the piston siezed from a fuel restriction. Yes the sleeve can be replaced even though it is a lot cheaper to bore.

 

[Scout Sport Fish]

Re: Engine wont turn

Whoa did I space out there bad, forgot we we're talking about a 2 stroke here haha.

 

[louisiana redneck]

Re: Engine wont turn

Correct, no valves. I am looking at the cylinder that the piston rides in and it looks like some aluminum got embeded in the wall of the cylinder. I can skim cut this out on a boring mill...i was looking at new oversized pistons & rings and it looks like .50mm will be the size i need.
Can i bore just the one? If the one is only bored will the proper amount of oil and gas be supplied to it? May a few thousands larger shouldnt matter anyway.

 

[louisiana redneck]

Re: Engine wont turn

Another question. Will i be able to break this motor even further apart (so i can pull the cylinder part out to machine) without messing with the flywheel and all the upper works?