Starting Problem - Mercruiser

[Capt.T]

My 1991 Mercruiser 5.7 litre, 260 hp V-8 fresh water - sea cooled engine recently developed a starting problem. Sometimes it starts and other times there is a grinding of the starter pinion gear on the flywheel ring gear. I installed a new Acro starter and the condition is the same. While changing the starter I rotated the flywheel and found no damage to the ring gear. I called Acro and they said I must have hydrolock, the technician was absolutely positive in his diagnosis. My exhaust manifolds and elbows were changed about 3 years ago, as were the exhaust flappers. I do not think it is hydrolock, once the engine starts, it runs perfect. I'm thinking it must be an electrical problem. Any suggestions? I enjoy working on the boat myself, but this has got me stumped.

 

[dukebrown]

Re: Starting Problem - Mercruiser

I would clean all your electrical conections from the battery to the starter. If it isn't able to draw enough amps on when the electric motor starts it won't be able to fully extent the pinion to the flywheel.

 

[NHGuy]

Re: Starting Problem - Mercruiser

Yup agreed, you need a good jolt of power to shoot the drive gear onto the ring gear. And to crank. How is the crank capacity of the battery?

 

[Bondo]

Re: Starting Problem - Mercruiser

I do not think it is hydrolock, once the engine starts, it runs perfect.

Ayuh,.... Pull the sparkplugs,+ then you'll Know, for sure...