Logo

PCM 351 with velvet drive 01710005 transmission

kurt_johnson

New member
"Boat has been sitting for a y

"Boat has been sitting for a year. Tryed to start and it locked up after trying to turn over one time. I have removed exhaust manifolds, valve covers, spark plugs, starter, and sprayed with fog oil. Engine turns 1/2 revolution and hits hard when manually rotated. Engine has no signs of rust. Could I have transmission problems? Any other suggestions?"
 
A Valve could be stuck open an

A Valve could be stuck open and the piston is stopping against it when you crank the engine. Remove the valve covers and look for a valve that is not moving when you turn it by hand using a big breaker on the crankshaft bolt in front of the engine. Don't use the starter or it will bend or break the valve.
 
"I have now removed the transm

"I have now removed the transmission from the 351 PCM engine and the engine is definitely locked up. The oil is full, no condensation at all, looks old but fine. I have already lubricated the pistons, valves, inside the exhaust ports. I have removed the valve covers and tryed watching the valves while turning the crankshaft with a breakover bar. Engine turns smoothly for 1/2 turn and stops hard. Not all the valves have time to turn with just 1/2 revolution. I then turn the other direction 1/2 turn and it stops hard again. What should I try next?"
 
"I would remove all of the roc

"I would remove all of the rocker arms. Kep them in order to replace them in the same place if you can. It is not so important since it is hydrolic lifters but everything is seated good where they are.
Then see if all valves are the same height or if one is stuck.
Something is blocking the piston from going to the top in one cylinder. Next try to put a 1/4" wood dowel in the spark plug hole an see if it moves when the piston comes up. Try each hole
Other posibilities are the timming chain locking up at some point or thedistributor gear.
The worst case is the crank and a broken rod. A replacement long block is around $1,000 so don't spend a lot trying to fix that one. I did and wish I had just replaced it to start with. It works now but I spent a lot of weekends on it."
 
I discovered my problem. I ha

I discovered my problem. I have a coat of rust in one of the pistons that was stopping the piston from going up. I am going to take the engine out and rebuild it with new gaskets. It only has 600 hrs on the motor and everything but that one cylinder is good. How should I fix the one cylinder with rust? Is there a product that will remove the rust?
 
My guess is that you had an ex

My guess is that you had an exhaust manifold leak. If the engine only has 600 hours but is old. You may have to remove the head and use a hone to clean the cylinder. If the rust is too deep then the block will need to be replaced. To bore it and rebuild it is morethan a long block. Use felpro head gaskets that are for marine engines. They are available from Felpro web site or from eBasicPower.
Plan to put new manifolds on too.
 
Back
Top