try turning it backwards, also remove the belts.

try turning to over with all plugs out and disconnected from the trans

Before you leave pull the spark plugs and squirt PB Blaster into the cylinders and let them soak while you're gone.

When you get back put a remote starter switch on the starter solenoid and a breaker bar on the balancer bolt. Gently push the breaker bar and hit the starter. It should break loose if it's just moisture/rust in the cylinders. Be careful, when it breaks loose the bar goes flying.

Did the spark plugs have any rust on the threads?

no rust on the threads and the plug tips were normal.

I like the above ideas and might try some of them tomorrow before I leave. We cancelled the boating part of the trip anyway at this point so ...if it can soak for a week - why not.

I'm betting on a locked up transmission. Can you spin the prop by hand with the transmission in neutral?

It has to be the trans. Even if the bearings were bad, it would normally turn over some. Small chance it's rings rusted to the bores. Be carefull with the 3 foot pipe on the crank bolt, it may break with that much torque.

All along I want to beleave its the trans.
If the Arneson spins then the rear part of the trans is ok.

I could never go away knowing I would have to come back to it.

Seperate the trans from bell housing.
Dont know what kind of rear engine mount your sporting
but if its between the bell and the trans and ya got the room you can sneak the bolts out and install a couple studs so you can slide the trans off without disrupting the engine.

I agree if it was a bearing on the crank it would creep

Good luck

Thanks guys - the trans is hydaulic and I can spin the shaft to the prop so it is in nuetral but who knows. If I can get it to turn with a bar on the flywheel I should be ok otherwise I might pull the trans when I get back from vacation.

Either way - I am filling the pistons with more 10W40 or whatever before I leave so it can soak. I might also try to put the counter-rotation motor's starter on this thing to spin it in the other direction a little.

Thanks everyone for your advice!

If ya do that with the counter starter make sure ya remove the
water pump belt

I looked at the plugs again this morning - no sign of rust or water at all....I'm thinking trans theory is making more sense too. I dont have the time to do it today so it will have to wait.

I can pull the u-joint drive shaft pretty easily (I have about four feet to work in rearward of the motor. Then I can disconnect the trans and pull it rearward enough I think to disconnect it. 100 lbs for that thing right? Gonna be rough on the back.

Then I can try spin the motor again with the starter (plugs out) and go from there.

Thanks everyone for your inputs - helps alot.