Pistons Frozen/ Flywheel won't turn

[Salder]

I just bought a 14 ft aluminum boat with a 1973 Johnson 9.5 hp Seahorse, model 9R73. The guy said the last time he took it out the motor ran really rough. After that he couldn't get it to turn over. That was in 99. He put transmission fluid in the cylinders and this didn't help. My brother told me to put WD-40 in the cylinders intead. Any suggestions. Flywheel will not turn at all. Should I spend 40.00 for a manual or consider the engine ruined?

 

[Terry H]

Re: Pistons Frozen/ Flywheel won't turn

Pull the head off...then ask again...

 

[rickdb1boat]

Re: Pistons Frozen/ Flywheel won't turn

Put some Marvel Mystery oil(No WD-40) in the spark plug holes and let it sit for a few days and try it again. If you get it to turn over, check the compression right away. That will tell the story.. As Chief 101 said, you could always pull the head and see whats up. I have heard that giving the pistons a whack with a hammer and a piece of wood has freed them up, also. But use the oil first.. Could also be the lower unit driveshaft is frozen and not letting the engine turn over..

 

[JB]

Re: Pistons Frozen/ Flywheel won't turn

Why would you post this in the non-repair forum, Chrysler?<br /><br />Moving to Chrysler Troubles.

 

[12Footer]

Re: Pistons Frozen/ Flywheel won't turn

But it's a Johnson, JB....Oh well, drop the lower unit and try to turn the flywheel. It may be the lower unit that is locked-up.