Mercruiser 3.o Seized or just me?

BigFuzzyBush

Recruit
Joined
Jun 23, 2015
Messages
4
I have a 1998 180 Sea Ray Bow Rider with a Mercruiser 3.0 and a Alpha One Out drive. Recently had to replace the starter so I decided to change the plugs and wires along the way. Rookie mistake I made was not paying attention to wear the wires went on the distributor cap. I followed the firing order instructions from another posting but I'm guessing the firing was out of order when attempted. Motor turned a few times then sounded like it got real tight which then took out my starter. Got a new starter (haven't reinstalled it yet), now I'm trying to find TDC so that I can get the firing order right. However, I can't seem to rotate the engine manually (unless I'm doing it wrong). I can turn the alternator but none of the belts seem to turn, just the pulleys. The the crankshaft pulley is not turning, just belts moving. Is there a chance I seized up the engine or am I completely overthinking this and just doing it all wrong? Any help youfolks can provide would be greatly appreciated. Thank you!
 
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CV16

Chief Petty Officer
Joined
Aug 30, 2007
Messages
445
Put a socket on the crank bolt and try to turn it. Pull all the plugs out first, makes it easier.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,587
Be extremely careful turning a motor with the crank bolt. Good way of shearing it right off. Using a strap wrench around the crankshaft is a way better idea.

Also, this thread shouldn't be in the Volvo area.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
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50,257
never turn a motor by the crank bolt. either pull the harmonic balancer and use one of these
http://www.walmart.com/ip/Moroso-61...9980&wl11=online&wl12=157554238&wl13=&veh=sem

or remove the starter and slowly rotate with a prybar and the ring gear teeth

or put long bolts into the 3 spots on the harmonic damper hub and pry from there.

turning the crank bolt will snap it off, often requiring the motor to be pulled to remove the broken bolt, a strap wrench on the outside of the damper may damage the damper. lower pulley would be fine.
 
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Alumarine

Captain
Joined
Feb 22, 2005
Messages
3,738
If you put pressure on the alternator belt as you turn the alternator that might help turn the motor.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,587
turning the crank bolt will snap it off, often requiring the motor to be pulled to remove the broken bolt, a strap wrench on the outside of the damper may damage the damper. lower pulley would be fine.
You are correct..never put any force on the damper.
 

NHGuy

Captain
Joined
May 21, 2009
Messages
3,631
So do the bolts in the center of the damper. Or do a crank turning device that goes on the damper or the crank.
OK, now the next thing, if the engine resists turning remove the spark plugs and try to turn it. When/if it shoots water out of the plug holes, dry them out well and then spray some WD40 in there to dry out the combustion chambers.
Then come back and let us know if that's what happened.

If there's no water in the plug holes do this:

Don't change the timing til needed if it was OK before.
But as said, if there's no water in the combustion chambers, remove the distributor cap and turn the engine over til the rotor points at #1 then install your plug wires starting at that spot.
Charge up your battery before you try the engine!
 

wahlejim

Master Chief Petty Officer
Joined
Jul 23, 2015
Messages
884
Just out of curiosity, how did you determine the starter was bad and needed to be replaced? I only ask because if the engine was hydro locked, it wouldn't turn over. Could be indicative of another problem. Exhaust system perhaps?
 
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