Strange starter issue.

[blando]

1998 4.3 mercruiser Vortec.
Starter bendix will engage for 1-2 rotations then just spins until next time I turn key to start, then 1-2 rotations of the flywheel then bendix gear retreats and on and on.
when I pulled plugs to check compression bendix will stay out as is when bench tested. It appears the starter works as it should when no resistance. While turning engine there is most time no attempt to start hence no reason for bendix gear to retreat. Compression was appropriate.
Any thoughts?

 

[Scott Danforth]

Clean your battery cable connections and make sure you have a fully charged battery

 

[blando]

Clean your battery cable connections and make sure you have a fully charged battery

Done and done. Cleaned all contacts. New battery w1000 cca. Fully charged.

 

[blando]

New starter last summer. But a lot of cranking today. Was fine yesterday and part of today with old battery. Could have damaged something with all the cranking.

 

[tank1949]

New starter last summer. But a lot of cranking today. Was fine yesterday and part of today with old battery. Could have damaged something with all the cranking.

Pray that you have a worn or bad starter bendex and NOT and bad ring gear.

 

[blando]

Pray that you have a worn or bad starter bendex and NOT and bad ring gear.

By ring gear you mean flywheel teeth? If so it's good. Not worn or broken teeth.

 

[blando]

I think it must be the starter or weak current due to that it'll operate normally when no plugs in motor. But with even one spark plug hole blocked with the compression gauge it kicks back the bendix gear. Thoughts??

 

[poconojoe]

It sure sounds like there's serious resistance somewhere since the battery is new and it only happens under engine compression.

You cleaned all contacts?
Disconnected every single one and cleaned shiny like new?
Even the negative connection on the engine block?

How do the battery cables look? Sometimes they can corrode under the insulation, usually near a connection. That happened to me once.

 

[blando]

It sure sounds like there's serious resistance somewhere since the battery is new and it only happens under engine compression.

You cleaned all contacts?
Disconnected every single one and cleaned shiny like new?
Even the negative connection on the engine block?

How do the battery cables look? Sometimes they can corrode under the insulation, usually near a connection. That happened to me once.

Thanks for responses. Anyone have this happen and it be a failing solenoid on top of starter?

 

[tank1949]

By ring gear you mean flywheel teeth? If so it's good. Not worn or broken teeth.

starter fails to 100 % engage ring gear on flywheel due to poor DC connection or weak battery or bad solenoid/Bendix (starter teeth). I replaced starter, ring gear and circuit breaker due to corrosion inside helm motor switch circuit breaker causing sh--- to fail.. Expensive learning.....

 

[blando]

starter fails to 100 % engage ring gear on flywheel due to poor DC connection or weak battery or bad solenoid/Bendix (starter teeth). I replaced starter, ring gear and circuit breaker due to corrosion inside helm motor switch circuit breaker causing sh--- to fail.. Expensive learning.....

It engaged 100% hence no grinding but for only 45-180 degrees then retracted.
New starter installed. All is well!

 

[blando]

I conclude it was prob the solenoid on top of starter that controls the bendix position failing.

 

[poconojoe]

It engaged 100% hence no grinding but for only 45-180 degrees then retracted.
New starter installed. All is well!

So, you're good?
If so, that's great!

 

[blando]

So, you're good?
If so, that's great!

Running like a champ. I narrowed it down to the starter by eliminating everything thing else, still wasn't 100% confident. But took the leap anyway and bought the starter. Thanks for the reply's.

 

[oldboat1]

GM starters have periodically used shims for years. Bendix gear (i.e., starter body) shimmed in to contact flywheel, particularly if flywheel worn. Sometimes just remounting the starter will get you going again. Auto Parts stores sell these shims.

If you have the starter that gave you trouble, try taking out the long screws and opening it up. Clean it with carb spray and check the brushes -- replace if needed. Keep starter as a spare.

 

[blando]

resurrecting this thread because its happening again. I cant keep throwing $300 starters at this thing. What could keep causing this problem.
I have a troublesome main harness plug that if it isnt in just right position when connected itll cause gauges to be all over the place and or no start, tach only works intermittently when i can get plug just right. I need new plug. but for now it was fine if in certain position and i know that can be troublesome with a vibrating bouncing moving boat but havent had any problem running like this for months . Boat ran great today but had trouble with starter only engaging one or two rotations( mostly one) today. could it be if plug is causing intermittent voltage or it could cause a brief laps in engine trying to fire and bendix retreating ???
There is what sounds almost like the motor locks up or kicks back every now and then when trying to start this could be killing the clutch if so , what is causing the engine to lock up or rotate backwards . Timing is correct, no water in cylinders . Boat runs 50mp without a hiccup.. usually starts right up.

 

[kenny nunez]

Pull the harness plug and with a small screwdriver slightly spread each pin and add a worm clamp to the plug and snug it up.
On the starter look at the #10 yellow/red wire. Get a remote starter button from the local auto store. When it starts not staying engaged connect the remote starter wires to the large battery post and the smaller #10 on the starter solenoid to see if it stays engaged.

 

[Scott Danforth]

see post #2

 

[blando]

Pull the harness plug and with a small screwdriver slightly spread each pin and add a worm clamp to the plug and snug it up.
On the starter look at the #10 yellow/red wire. Get a remote starter button from the local auto store. When it starts not staying engaged connect the remote starter wires to the large battery post and the smaller #10 on the starter solenoid to see if it stays engaged.

thanks for the quick response

ive done that with the harness and it has a worm clamp. i fear some of the pins are loose and or corroded and broken off in the male plug. ive also carefully dremled out the female connecters to remove any corrosion.

im not understanding
look at #10 yellow/red wire ... what am i looking for

so connect the remote starter wires to the large battery post on the starter or on the battery?

and the smaller #10 on the starter solenoid to see if it stays engaged?

 

[blando]

see post #2

lol.. unfortunately both are good..