Motor won't turn

[Throbbin Rods]

I donated a boat and 40 hp Johnson to my stepson for a project. He has it almost ready to go. When I brought the boat and motor into the garage it turned fine. Last week we tried to start the motor to veriy water in the telltale etc and the motor won't turn. I tilted the motor all the way up and filled the cylinders with Marvel Mystery oil which has worked for me in the past. So far no luck but if I put a dowel in the spark plug hole and try to turn the motor with a ratched I can feel the pistons moving slightly. Am I correct in assuming that the rings are just stuck?

 

[Chris1956]

It could also be the gearcase is seized. You might drop it and see if that helps.

 

[Throbbin Rods]

It could also be the gearcase is seized. You might drop it and see if that helps.

I was able to get it loose and it now runs v ery nicely and had great compression

 

[boobie]

What was wrong with it ????

 

[ct1762@gmail.com]

how did you turn the motor with a ratchet through the spark plug hole? or are you saying you turned the flywheel with a ratchet and watched the dowl in the plug hole?

 

[boobie]

Well, what was wrong with it ?? Be nice to hear from you.

 

[Crosbyman]

they come and go...

 

[webbd]

how did you turn the motor with a ratchet through the spark plug hole? or are you saying you turned the flywheel with a ratchet and watched the dowl in the plug hole?

I think... Dowel in the spark plug hole to measure movement, ratchet on the flywheel nut to turn the motor.

One motorcycle shop in Cleveland likes to unstick old Honda motors (after soaking) with a grease gun and adapter screwed into the spark plug hole. Seems good for a 1-cylinder, but might not be good for a multi. Marvel Mystery Oil is always helpful.

- DW

 

[racerone]

That grease gun trick only works on a 2 strokes if piston and rings are closing off the ports.