srl520

Did a search and found this link that is pretty much the same issue that I am having.
http://www.offshoreonly.com/forums/d...r-problem.html

I had motor rebuilt couple months ago (502mag). Good time to have the starter and alternator rebuilt although I had no problems with either one.

Installed same starter, same bolts (GM gear reduction starter) only things different where new silenoid, bendix
and other new interior parts.

First thing I noticed when starting the first time was it turned over slow. Made sure batteries up to charge and they where. Re-checked connections. Made sure I sanded new paint off starter where bolted to block.

Now it turns over fine. Started it many times in the shop. No problems.

Went to the lake to back it off trailer. Turned the key, nothing happened. Fooled with neutral switch/shifter to make sure in neutral, nothing. After 5-6 times turning the key the starter engaged and was grinding. Did it a couple more times and it quit grinding and started. Started fine the rest of the day. Next time went to the lake it was intermittent doing it again.
Then it went to only grinding evertime.
Pulled starter found cracked housing.
Back to rebuilder and replaced broken parts (housing, Bendix)

Reinstalled worked fine in shop.

Went to the lake and worked fine till time to come back to marina. It engaged and grinded again. Tried a couple times again and then respun.

I removed it again and broke another housing.

I double checked the bolts where extra tight when putting in second time. The bolts are the 3/8s with neralled shank.

My only thinking is the starter is moving after couple uses. But I am using the same components as before the problem.

Any other ideas?

T-Mone

check starter solinoid, sounds like problem i had. replaced it now its starts fine

kubelwagonman

bet its the slave solenoid,,,,,common on marine engines

mike tkach

iTrader: (3)

make sure the bolts are not bottiming out,ad a washer on both bolts,hope this helps.

srl520

Ok, update from this wkend.

Had starter rebuilt again. New bendix, silenoid, new housing. Went to GM and purchased new bolts. Ground 3/16 of inch off them.
Installed started and crancked bolts as tight as possible.

Started fine on trailer. Went to lake. Started it dozen times before leaving the landing.
Went on 15min cruise to beach. 2hrs later went to start it and this is what happened.
Turned the key. Nothing. Double checked shifter in neutral. Turned key again and there was a slight hesitation and then the starter engaged and started into grinding.
Turned key off before damaging anything. Turned motor with breaker bar quarter turn. Tried again. Same thing.
I then loosened the starter bolts, shook the starter alittle and tightened the bolts again.
Turned the key and it started right up. Turned it off and started up again.
Cruised back to landing and loaded onto trailer.

Anymore ideas?

srl520

Another idea I was thinking of is I have had a starter turn over slow and then speed up when engine is warm and or when the timing is advanced to far.
Timing is set at 34 degrees. The other motor is also set at 34 degrees with no problems.
It almost acts like the motor spins over hard when it grinds and the starter has enough torque to spin faster than the motor turns and eventually breaks the housing.

Any ideas on this one?

mike tkach

iTrader: (3)

did u tru adding a shim between the starter&block?

srl520

I have not added shims yet. Talked with a few different boat mechanics last week and one of them suggested shimming. Two others that have been mechanics for 20yrs say you don't need to shim these.
What gets me is if it needs to be shimmed I would think it would bind everytime.
I think I may consider this.

skydog

Sounds like a ground problem to me. When u loosened starter and tightened back up and she was good. Run a ground wire to check from bat to starter. Good luck I feel for u I have been in starter Hell too!!! Hahaha sucks

Skydog

4bus

iTrader: (4)

I went through this exactly a few years ago on my port side 500hp, in fact I ended up taking teeth out of my flywheel ring.

I don't know how you can put a shim in correctly with the engine in the boat, unless you guess. I lifted the port engine high enough to remove the starter, bell housing and flywheel. Changed ring gear, removed inspection plate from bell housing, then replaced starter and used a shim kit that had 4 different shim sizes. After trial and error shim #3 was the ticket. Never had a problem again.

I sold those engines after a re-power. The new owner replaced the starters just "because". He had the same problem, he never saw the shim when he removed the old starters. He replaced the shim and no issues

BTW, only use OEM GM bolts!