5.7 L Mercruiser won't turn over

[gmst2]

Cannot get the motor to turn over. Removed both heads and still cannot get the pistons to move. No sign of water in the oil or in the bores.

 

[Fun Times]

Hi there, welcome to iboats!

Have you tried removing the complete stern drive unit off of the boat? If the stern drive is seized/locked up due to internal damage then the engine will not be able to turn over no mater what gear your in.

Is this an Alpha stern drive? What year?

 

[gmst2]

Thanks for the welcome.
​Just purchased the boat, was told it hadn't been used for 3 years. The boat is 1990, sterndrive is SE 106 which I have removed. The serial numbers on the housing indicate it is same era as the boat.

 

[Bondo]

[QUOTEThe boat is 1990, sterndrive is SE 106 which I have removed.][/QUOTE]

Ayuh,..... Welcome Aboard,..... Pullin' the drive is step 1 in the diagnostics, as well as in pullin' the motor,....

I guess pullin' the motor is where yer at now,....

Has the starter been tested,..??

Is the battery up to the task,..??

When ya turn the key, What happens,..??

 

[Bt Doctur]

Well, thats a lot of wasted work if its the battery or the battery connections or a wet solenoid or drowned starter.
Do the basics first, battery, cables , and the connections. Then if nothing remove the starter for testing.
If still no go, make up a "T" handel with a used shaft and some 1 inch gas pipe and insert into the coupler