Starter Motor issues

[ThePinkPanther]

This might have to be under ELECTRICS so apologies if in wrong forum!

I have an inboard motor - Ford 351 Windsor V8 - and found the starter motor to be kind of noisy lately when first engaged, kind of loud metallic clash but it only lasts for a second and then motor start quite easily. Sounded like the pinion gear not fully engaging initially..........................?

Anyhow, I decided to fit a new one as this one is pretty old and had a bit of a dunking many years back when the bilge flooded, duh, when I left the bung IN during heavy rain!

Now it has deteriorated into a total inability to engage at all and the (dreadful) sound is what you would expect when the pinion is ratcheting against the fly wheel. I didn't persist with this cycle for more than a second or two at most!

So, in goes the (correct) new motor and bugger me, exactly the same problem!

Couldn't believe it, not with two starters!

So, appeared obvious to me that there was a serious drop of voltage between the two (new) batteries and the solenoid!

Both batts read 12.5 V and ditto to the positive of the solenoid, so more than enough to engage the starter, or so I thought!

But no way! Just refuses to engage! Can't possibly be starter motor problems as I can't believe a brand new one and a fully functioning older one would both have the same mechanical issue.

I put a voltmeter across the positive of the solenoid and during the cranking attempt recorded a health 10.5V being more than enough to start the boat, I think! My voltmeter on the instrument panel used to show about 8-9 volts during starting arose.

So what can be causing this?

Got me beaten but, the motor was recently completely reconditioned and is obviously very tight not being run in yet. Maybe the compression is too high for the 10.5V to turn it over? Clutching at straws here!

I really do suspect the voltage drop is just too much to kick over the as-new motor! I doubt I have a dud cell in a battery as the 10.5V on start is not all that bad I would have thought?

Any help appreciated thanks guys!

[Gon Fishun]

Did you inspect the ring gear when you changed the starter motor? Teeth possibly worn away.

[gkurth]

You should be getting about 13.4 to 13.8 volts on a good battery. At 12.5volts its time for a recharge

[ThePinkPanther]

Yep, ring gear perfect and think GKGIRTH is on the mark! might be as little as half or one volt causing the problem,especially with a newly reconditioned motor still being very tight and needing a bit of oooomph to turn it! Thanks for replies!

[ThePinkPanther]

Damn! Back to square one guys!

Had my local auto electrician recharge and load test both the as-new batteries and they came up A1.

I have one brand new starter motor and one older though fully functional one and they both produce a ratcheting noise on start up as obviously the pinion gear is not engaging in the ring gear.

I tried shorting out the solenoid across the terminals with a screwdriver but same result.

Pretty hard to get the wiring mixed up as there is just the one positive terminal, negative through the bolt holding the starter on and the negative exciter wire to the spade terminal from the ignition switch.

I am starting to fear that there is a ring gear problem but the motor was fully reconditioned only a month ago by a marine mechanic and has been starting and running fine up until now!

I'm beat! Any ideas much appreciated!

[Gon Fishun]

From memory those starter motors, on the initial hit up dragged approx 800 amps, so good batteries were a must, and the motor when turned off, stopped in the only a few spots, which tended to wear the ring gear in those spots. Is the starter motor mounting up flush to the bell housing, every thing clean, flat , etc.

PS. pull the starter off and check the ring gear. Even if the motor was out and reco the ring gear might not have been replaced.

[ThePinkPanther]

Thanks Mate! Advice much appreciated!

In a minute I'm going to go down and turn the motor over by hand and move the ring gear around in case, as you say, there is a worn spot that the pinion is hitting against! The ring gear looks fine from what I can see of it the bell housing and re the batteries, you just couldn't get them better! 13V and 11.5 across the solenoid during the start attempt.

Nothing makes sense because the boat has been running with this same starter motor in it from when I picked it up after the overhaul.

And with two starters both giving the same problem, just has to be electrics but I'm buggered if I can think where?

Everywhere I look I come up with voltages well in excess of 12V so it's got me ........................

[ThePinkPanther]

You were on the mark Mate, turned it over by hand a few times and burst into life again! Never struck that before, one more thing to store away! Cheers

Can't find the bit about "problem solved" or how to post you a thanks? Must be here somewhere ..............?

[Gon Fishun]

Your welcome. Glad you had a good outcome. I'm off to flick some plastics around the passage.

Cheers.

[ThePinkPanther]

Bugga! I spoke too soon!

After the above action of turning the motor by hand a few times it roared into life, turned it off after about ten minutes, tried to restart it and back came the same pinion gear racheting problem again!

How come the flywheel cones to stop in the same position everytime where there must be a worn bunch of teeth or a flat spot?

I turned it it by hand again and no problems on starting!

Thing is that before the total rebuild of the V8 inboard, I never ever had this issue so how come it had suddenly surfaced now?

This will drive me nuts if I have to carry a socket spanner on every trip to help in starting the brute?

Any ideas how to attack this one thanks?

[Gon Fishun]

The reason it has surfaced is the rebuilt engine. Tighter, harder to turnover, and the ring gear probably had a lot of wear to begin with.
I can't remember why some motors stop in one particular place more often than others. Some of the other guy's on here will know.
You will have to fit a new ring gear to the fly wheel or replace the flex plate or whatever they have.

[ThePinkPanther]

Aaaagghhhhh! Can't be done! That would be pulling the motor (again) and that is about two grand plus just to get it on a hard stand, use of the lifter and the slow mechanic to do the job!

Looksl like a socket spanner!

I need a strong rum and coke right now, but thanks anyway! I'm think!

[MyWay]

if you replace bendix gear with new one it may be just bit stronger spring to engage better with flywheel to start every time ,
if you going to do get good quality bendix .
rebuilt starter may cost you only $150
just

[ThePinkPanther]

Not sure what to do now! Just cost me about six grand to have the motor rebuilt from front to back and that included hard stand fees etc.

To pull the motor again would be a minimum of $2,500 and I can't see the mechanic doing it for nothing! Thing is I asked him to check the ring gear when the work was being done but would he have seen this flat spot, probably not!

I'm wondering that as the motor loosens up if this problem will disappear?

Geeeez, what a fix!

[Gon Fishun]

It will only get worse. If said mechanic was supposed to check ring gear and he hasn't, put it back on him. I would be removing the starter motor and having a real good look at it before hounding him but.
I haven't had anything to do with the removal of those motors, had a look on Google, looks messy, but is there any way to fit a gantry in there just to move the motor enough to get to it.
After thought, Give Captain Rednut a hoy on Ausfish, he's tops in that kind of thing.