1987 mercruiser 3.0 is stuck. Can't turn.

benzoc

Recruit
Joined
Dec 6, 2013
Messages
1
1987 mercruiser 3.0 is stuck. Can't turn. Have tried to trun power steering pump with number 1 plug removed. Has short block installed 2 years ago. Winterized evrt year since.Starter will not engage flywheel and I don't want to damage engine. No visible cracks and oil is clear. How can I manually turn engine
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,307
Welcome aboard.

first, pull the drive to make sure the drive isnt locked up. then pull all the plugs and you should manually be able to rotate the motor by grabbing the belts by hand.

also, take the starter off and have the starter serviced.
 

thumpar

Admiral
Joined
Jun 21, 2007
Messages
6,138
Do as Scott said. It could be the engine or the drive is locked up. You need to find out which one before going further.
 

Alumarine

Captain
Joined
Feb 22, 2005
Messages
3,684
Do you think it's seized or do you just want to know how to rotate it without the starter?
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,093
the starter should be able to spin the motor, if it dosent engage the flywheel that's another issue
remove the drive ,using a old inputshaft with a T extention welded to it ,insert into coupler, turn engine.
if it was winterized properly, it should still spin.remove all the plugs and insert some medical swabs(the long ones) into the cylinders to check for water or rust.
 

BruKen

Seaman Apprentice
Joined
Feb 26, 2014
Messages
48
Any luck with this yet? This season past mine sheared a starter motor bolt and the starter rotated slightly jamming up the works. Coincidently a couple of others here at the same time had a similar issue.
 
Top