mercruiser grinding when starting, missing tooth, hydrolock?

[Fixing mercrui]

Hello, I have a 1998 5.7 litre fresh water cooled mercruiser. I am the 3rd oner. This will be my 3rd season using. Orig owner used boat upsate NY in fresh water lakes untill 2007. 2nd owner used boat in saltwater untill 2010. My First season in 2011 no problems. last season towards end, I started getting a grinding sound when starting, not always though. got more frequent towards the end of the season. Got boat out and flushed and winterized for winter. The exhaust manifolds were definately the originals, never replaced, I have all the previous owners bills. This spring, I removed the starter. Had it tested, one merc dealer said starter was fine, put power to it, gear shot out and turned as it seems like it should. A rebuilder said it was bad, the gear which was not chipped or marked up, but would rotate freely with your fingers, he said it should not do that, should be tight. Purchased a rebuilt one from him. 1- Do you think the starter was bad, or good? Before putting it in, I checed the flywheel by rotating with socket on wheel balancer. One tooth was broken, see pic. It loos so rusted like it has been that way for awile, just saying. I puled the exhaust manifolds, they were pretty bad, and am going to replace them. I figured they were past due to be replaced anyway, and may have leaked and caused hydrolock. I am going to replace the exhaust shutters as well. 2-Could hydrolock be the cause of my broken tooth and broken starter gear clutch? 3-Can I get away without fixing the flywheel missing tooth if no more hydrolock is possible since I will be replacing all those parts? I really dont want to have to pull the motor to fix the flywheel as I dont have a hoist to do so. I can always try and do it next year if possible. Should it get stopped on the bad spot, I will have a bar with socket to move the engine a few degrees.

Thanks in adance for alll your input!

 

[1960 Starflite]

Re: mercruiser grinding when starting, missing tooth, hydrolock?

The pictures of the flywheel look like your starter may be shimmed too far from flywheel. Is the engine a Chevy? If the starter bolts up sorta from the bottom of the block, there are shims between the block and starter mounting base. Generally a engine will stop at just a couple of places, if the starter hasn't engaged the flywheel (just spins) a few times, time to change the flywheel. I think if you get the engagement of the gears a little closer, you shouldn't worry about the ONE broken tooth.

Can't help on the hydrolock.

 

[series60]

Re: mercruiser grinding when starting, missing tooth, hydrolock?

2-Could hydrolock be the cause of my broken tooth and broken starter gear clutch?

Possibly but there isn't much tooth contact between gears. Was the starter bolted up tight? Are there any shims between the starter and the engine?

3-Can I get away without fixing the flywheel missing tooth?

Probably, but I would try to determine why there is so little contact between bendix gear and flex plate ring gear.

 

[Fixing mercrui]

Re: mercruiser grinding when starting, missing tooth, hydrolock?

This is a chevy engine. The starter does bolt up from the bottom. When I took it out, the bolts were very tight, and there were no shims. Starter worked fine for me for a year and a half. Grinding noise would only happen intermittently, sometimes worked fine, other times it grinded and woulnt turn over.

thanks again gents!!

Also, it never just spun free, it only cranked nice and hard and would start, or it would grind and not turn over. When it did grind, after a few clicks, then it would catch.

 

[Rockinsince85]

Re: mercruiser grinding when starting, missing tooth, hydrolock?

Whats the oil look like? Pull the plugs and look into the cylinders?

 

[Fixing mercrui]

Re: mercruiser grinding when starting, missing tooth, hydrolock?

Whats the oil look like? Pull the plugs and look into the cylinders?

The oil is clean, no water/milky color. The pugs had no rust on them, cylinders looked fine.

thanks again

 

[Fixing mercrui]

Re: mercruiser grinding when starting, missing tooth, hydrolock?

How could I possibly get the bendix gear to get closer to the flywheel teeth to have better contact?

 

[Fixing mercrui]

Re: mercruiser grinding when starting, missing tooth, hydrolock?

Well, fired it up, with new starter no grinding noise, and havent landed on the bad tooth spot yet, or it just isnt making a difference if I did land on it. Thanks all for your info!

 

[96Chappy]

Re: mercruiser grinding when starting, missing tooth, hydrolock?

I know its been a little while but I am having the same issue as of late. Boat starts fine in the driveway and at the dock, then once hot half a crank and just spins. Pulled the starter and bench tested and solenoid works fine and all spins like it should. Did you have to add shims? just gonna replace starter so I don't have to worry, but not sure if I should shim or not.