Mercruiser 3.0 engine sieze question

[tpenfield]

Re: Mercruiser 3.0 engine sieze question

the starter might have a better chance of turning the engine over at this point, with the drive off. . .

 

[120_i/o]

Re: Mercruiser 3.0 engine sieze question

Just wondering... how did you check the starter? Was it load tested?

 

[healy55]

Re: Mercruiser 3.0 engine sieze question

I checked voltage from the battery to the starter, across the fuse, to the slave relay, and the voltage stayed the same, no voltage drop or resistance. Wires and connections look all good. Load test? Don't know the procedure for that. I'm going to buy a new battery next before I dig into the engine.

 

[achris]

Re: Mercruiser 3.0 engine sieze question

... and the voltage stayed the same, ...

That is not right. You should have about 13 volts without turning the key. If the engine is seized (or too tight to turn with the starter motor) the volt will drop SIGNIFICANTLY.... As low as about 9 volts. If you have NO voltage drop, then you may also have a starter motor or wiring problem...

 

[Don S]

Re: Mercruiser 3.0 engine sieze question

The battery gets load tested, not the starter. As achris mentioned, you should see a large voltage drop on the battery when cranking the engine. Put your meter on the + and - terminals of the battery and hit the starter. It should drop, if not do you hear the starter or the slave solenoid click? If not follow this link. http://forums.iboats.com/showthread.php?t=167035

 

[120_i/o]

Re: Mercruiser 3.0 engine sieze question

Thanx for the clarification as I was too short with my question, but this procedure mentioned is a way of testing the starter under load for draw, and to what I was eluding before!!

 

[healy55]

Re: Mercruiser 3.0 engine sieze question

That is not right. You should have about 13 volts without turning the key. If the engine is seized (or too tight to turn with the starter motor) the volt will drop SIGNIFICANTLY.... As low as about 9 volts. If you have NO voltage drop, then you may also have a starter motor or wiring problem...

Yea I agree....the test I did was for resistance purpose...checking for bad connections or bad fuse or whatever. I didn't load test it. I need a 2nd person....my arms are not that long...lol. But will do after I get a new battery. Thanks!

 

[120_i/o]

Re: Mercruiser 3.0 engine sieze question

Might I add, if the voltage drop is real low this could also indicate high draw from either bad brushes/comm, or both in the starter too!!

 

[healy55]

Re: Mercruiser 3.0 engine sieze question

Thanks for everyones help! I installed a new battery rated at 840 cranking amps instead of cheap autozone 550 cranking amps...and it cranked over nice with drive disconnected and plugs pulled. Cranked it for a few 20 second bursts to clean out marvel mystery oil and PBC blaster. The autozone cheap battery was completely dead and dry and although I filled it with distilled water and charged it before all this...the top charge it would read was only 11.7 volts....with 550 cranking amps. The engine was seized and the Marvel mystery oil and hand crank broke it free and cleaned it. With a decent battery I'm in good shape for now. Should I do anything with the drive while it is off? Just curious. Going to pick up a gasket tomorrow and install drive. Next....anticipating carb issues! lol I will get it started!

 

[healy55]

Re: Mercruiser 3.0 engine sieze question

Might I add, if the voltage drop is real low this could also indicate high draw from either bad brushes/comm, or both in the starter too!!

Good to know!

 

[Utahboatnut]

Re: Mercruiser 3.0 engine sieze question

i would do a water pump impeller while the drive is off (at a minimum) also check gimbal brng. bellows, grease, alignment. Did you inspect any of the engine internals- remove valve cover and have a look(rust up there means rust down low. Bearings dont like rust how did the oil look? shine a HI pen light down the spark plug hole and try to see cyl wall condition. If you get her running I would change the oil frequently at first and keep a real good eye on oil levels and condition. Good luck...