Flywheel wont turn

[JerrfyLube]

Ok, so i took the shroud and top cover off my 1965 650 Merc and wanted to see in the motor will spin over. Pulled all the plugs and they all look good...a little carbed up and oily but no signs of engine damage. I had sprayed a healthy shot of penetrating oil down each cylinder last night. I tried to turn the flywheel and it will only turn about 1/4-1/2" in either direction. I can visually see all the pistons and they all move a little bit so i dont think anything is seized up...why wont it turn?? Shifting in an out of gear doesnt seem to help any.

 

[chicknwing]

Re: Flywheel wont turn

First thing that comes to my mind is a broken rod, rusted cylinder walls.

TC

 

[JerrfyLube]

Re: Flywheel wont turn

If it was a broken rod, why would all the pistons move, albeit, slightly?

And if it was rust, i would think with all the PB Blaster i sprayed in the cylinders and putting a decent amount of torque on the flywheel, would break it loose...

 

[chicknwing]

Re: Flywheel wont turn

A rod that's broken will move to the point where it comes in contact with the cylinder wall thus stopping movement. That's just the first thing that came to mind, I;m sure someone else will be along with an opinion.

TC

 

[airframer]

Re: Flywheel wont turn

has it ever overheated?

 

[Droll]

Re: Flywheel wont turn

Remove the lower unit first just to make sure it's not the problem....

Second....find a big screwdriver and try to push the pistons downward, shouldn't be any bigger movement without moving the flywheel.

Next thing you could try, were to remove the intake port cover ( starboard side ), this should give you some access directly into the pistons, at least enough to diagnose the problem ( check for movement, checking the rings tension ( no tension = broken )).

When was the last time it were used ?, has it been stored for a long time ?, has it been submerged ?

Arne Kjetil

 

[JerrfyLube]

Re: Flywheel wont turn

Its been stored for the last few years in someones garage. Was running before it was stored, or so they say. Im thinking it might be a lower unit issue as something just doesnt feel right when you spin the prop.

 

[Moody Blue]

Re: Flywheel wont turn

Any history on this motor? New to you? Run recently?

Wondering why you sprayed penetrating oil before trying to turn it over. Sounds like more to this story

 

[JerrfyLube]

Re: Flywheel wont turn

Wondering why you sprayed penetrating oil before trying to turn it over. Sounds like more to this story

Because i dont know how long its been since it last ran and some oil down in the cylinders should do nothing but good...and its what i use for a compression test(which i was going to TRY to perform till i found out it wouldnt turn over).

Its Marvel Mystery Oil in case anyone was wondering...