motor won't turn over

[Lance Stiffler]

I've got a 454 jetboat I used it last September without any problem. Stored it away for the winter. Went to get it ready for my first river trip of the season and the motor is locked up and won't turn over. Any help?

 

[tdonoughue]

Does it crank at all? Battery tested?

 

[Cobra Jet Steering LLC]

first you need to determine if it is the pump that locked up or the engine locked up.

 

[Gmmastertech1]

Could be the starter itself. First determine if the engine is actually locked, pump locked or starter concern. Need more details

 

[Lance Stiffler]

Does it crank at all? Battery tested?

Does it crank at all? Battery tested?

No it didn't crank at all and the battery is good

 

[Lance Stiffler]

first you need to determine if it is the pump that locked up or the engine locked up.

 

[Lance Stiffler]

How do I determine if the pump is locked up or if it's the moto?

 

[Lance Stiffler]

How do I determine if it's the pump or the motor

 

[Lance Stiffler]

Could be the starter itself. First determine if the engine is actually locked, pump locked or starter concern. Need more details

I've taken the starter off and nothing.

 

[BlacklimitedS]

If you have the starter off use a large flat screwdriver and tape the flywheel. It only needs to move a small amount. Pull the spark plugs to release compression. Do not pound the screw driver and break the teeth off the flywheel. Can you unbolt the pump away from the motor? Usually those big blocks have most of the motor and pump exposed for easier access.

 

[tdonoughue]

Wait--if the starter is off and cranking it does nothing, then the issue is not the motor, it is the starter or the solenoid or the switch. Or perhaps the wires going to the starter.

Right?

 

[Gmmastertech1]

If the starter is off, have it bench tested. Or, you can do this yourself with a battery charger or cables. If the starter is back on the engine, ensure the battery is fully charged, then touch the large post of the starter lug with the small lug. This will engage the starter. Be careful and not touch anything else. If this does not engage it, you have a main cable problem or the starter is shot.

 

[Lance Stiffler]

Wait--if the starter is off and cranking it does nothing, then the issue is not the motor, it is the starter or the solenoid or the switch. Or perhaps the wires going to the starter.

Right?

 

[Lance Stiffler]

No I also have the starter off I'm trying to turn it by hand

 

[Lance Stiffler]

I don't want to tear the whole motor apart if it's the jet that bad

 

[Cobra Jet Steering LLC]

I believe I told you to check it at the p t o on the back of the engine either the pump side will move a bit or the engine side will move a bit the side that won't move is where the problem is.

 

[Lance Stiffler]

Ok it's not the jet it turns and the motor doesn't. What is my next step?

 

[tdonoughue]

I would pull all of the plugs next and try to turn the engine. Without compression you should be able to do so. Also examine the plugs to see any that are not clean and normal.

(edited to clarify to try to turn _the engine_)

 

[Lance Stiffler]

I've done that

 

[tdonoughue]

And? Plugs all clean?

Assuming that they are, did you fog before you put it away? Is your oil clear (not milky) and no evidence of water (if it hasn't been started in a while, the water may separate out)?

The only thing I can think at this point is that there was some moisture somewhere internal to the engine that has caused some rust on a ring or something and is freezing it up. If there is no starter on the engine and no plugs and the pump is disconnected, you should be able to turn the crankshaft. If it was running when you put it away, that would eliminate a thrown rod or something catastrophic like that.

I think I would get some fogging oil, fog the pistons and let it sit overnight and see if you can turn it then. Otherwise, I fear you may be in for a teardown.

Unless someone else has some other thoughts...