Seized outboard? Sort of siezed

[CalicoJack]

At the end of last year I ran my elderly 15hp Tohatsu in fresh water and then removed the plugs and put some oil down the bores. Today when I tried to start it it was siezed solid. I then removed the rope starter and put a socket and short bar on the flywheel nut, I could not get it to turn in the correct direction, but i did get it to turn the other way, ie backwards. It will not turn through 360 degrees, but it will turn, very easily, though about 270 degrees, and then stops absolutely solidly.

Any thoughts on what might have happened? My thoughts for what they are worth is that one of the cylinders was at or close to TDC and somehow corrosion has set in on the bore, thus preventing it from passing through TDC. Currently I have filled both cylinders with 2 stroke mix and am letting it soak.

Any thoughts on cause or solution?
Thanks,
Nigel

 

[RichardS]

How much oil did you put in the bores?

Are you trying to turn the engine with the plugs removed?

Can you see anything odd with a torch through the plug holes?

It sounds as if you need to jiggle it up and down with the plugs removed as it might be a line of rust which just needs to be removed.

Richard

 

[RichardS]

Repeat Deleted

 

[CalicoJack]

How much oil did you put in the bores?

Are you trying to turn the engine with the plugs removed?

Can you see anything odd with a torch through the plug holes?

It sounds as if you need to jiggle it up and down with the plugs removed as it might be a line of rust which just needs to be removed.

Richard

yes, plugs out and the oil has been down there since January, so I’m guessing that it will have seeped its way out past the ring anyway. Like you I’m thinking/hoping it’s a thin line of rust and the 2 stroke will deal with it. Can’t see anything odd in the bores, although I can only see the top one.

 

[fredrussell]

Squirt a load of plusgas in cylinders and leave overnight. Wonderful stuff.