Correct starter motor

[thrasher]

Ladies and Gentlemen,

Some of you may recall this, but for those that don't here's a quick summary. I bought a 1991 Glastron 19' boat with an Alpha 1 gen 2, 4.3L V6 mercury engine about 2 months ago and failed to spot that the starter motor mount on the engine was broken. Fortunately their are 2 mounting holes and only one mount is broken, the second is perfect. This allows me to mount the new starter motor with one bolt whilst I find a repair for the second broken mount.

I contacted Mercury with my engine serial number (D714846) and asked them what was the correct starter motor, they gave me the following numbers:-
863007A1 for a new starter motor or 864340R02 for a remanufactured starter motor. I decided to buy the remanufactured motor (its cheaper) and fit it. The starter motor worked a couple of times (4 or 5 times) then started making grinding noises. I decided the only thing to do was remove the engine from the boat, remove the bell housing and see what was really going on.
I have removed the engine and the bell housing and can now see that this starter motor only allows the starter gear to come out far enough that the gears are only engaging for half the width of the ring gear on the flywheel. I mean that the gear ring is about half an inch wide, and the starter motor can only allow a quater of an inch of overlap between the 2 gears. The starter motor gear needs to come out another quater inch, but it can't as it has reached the limit of its travel. Also the casting at the end of the starter gear is touching the flywheel gear. If I remove the mounting bolts and move the starter motor towards the flywheel by a quater inch, then everything looks to line up perfectly (except the starter motor mounting holes!).
This leads me to believe that Mercury have given me the wrong starter motor model number. I have contacted them by email, but as it's the weekend I won't get an answer until Monday, so I thought I would ask for advise here. Do any of you know if Mercury sells an equivalent starter motor to the 50-864340r02 with the mounting holes quater of an inch further away from the starter gear? If this is the correct starter motor, what else could cause it to be out of alignement by a quater inch?

Many thanks.

Gary

 

[Bondo]

Re: Correct starter motor

Check to see if the Ring Gear is properly mounted,...

Chevies only use 2 different starters,......

Straight Across Bolts,+ Staggered Bolts......

I suggest that you have the Right Starter, but you Obviously have a starter Mounting Issue.......
If it lasted 4 or 5 starts with only 1 bolt holding it,.......
You got 3 or 4 More starts than I'd have Thought you'd get.........

 

[DHPMARINE]

Re: Correct starter motor

With only one bolt the starter is binding due to miss-alignment.Think about it. It's amazing that that little starter can turn over that big motor.Missing a bolt,no way it'll stay positioned correctly.

DHP

 

[thrasher]

Re: Correct starter motor

Thanks guys, but I guess I was not very clear. The starter mount bolts are a staggered mount. I fitted a second bolt so the motor has not been started with one bolt holding the starter motor, but only one bolt is in the original mount, the second bolt goes through a steel bracket that I fabricated. My fabrication might be out on alignement, which means the starter motor could rotate around the 1 good bolt, but that would only change the engagement of the teeth, not the amount the starter motor gear can move laterally. The bolts are straight and I cannot see anything that is bent to cause the starter motor to be out by 1/4 inch.. I have looked at the gear ring and it cannot move any closer to the starter gear or it would come off the flywheel, so I assume its in the correct position. I will look to see if the whole flywheel has somehow moved outwards by 1/4 inch (but that seems very unlikely).

Gary

 

[Coors]

Re: Correct starter motor

We need pictures...

 

[DHPMARINE]

Re: Correct starter motor

Pull the starter and bench test it.If the drive gear doesn't come out to the end of the nose,there is a problem with the starter. If it comes out to the nose,problem is with the engine.A slight miss-alignment can do this.

Another factor could be water ingestion,making the engine hard to turn over.

DHP

 

[thrasher]

Re: Correct starter motor

Thanks DHP,

I have bench tested it and the gear comes out all the way, the trouble is that all the way is not enough to ensure full engagement with the ring gear. I have removed all 6 spark plugs and the engine turns over fine, there is no signs of water in the oil, so I don't think its water causing the problem. It really looks like the starter motor needs a longer throw on the starter gear, or the entire starter motor needs moving a 1/4 inch closer to the flywheel. I have included some pics. Hopefully you can see what I mean.

Gary

 

[Bondo]

Re: Correct starter motor

You're getting 2/3rds engagement,....... I've Never seen 1 with Full tooth engagement.....

The 1st picture Looks like the starter Isn't Square to the Flywheel.....

 

[thrasher]

Re: Correct starter motor

Hi Bondo, I agree it isn't square. I believe that's because the cast hoiusing at the end of the starter motor is touching the teeth of the flywheel, preventing the motor from turning inwards a bit further to where it would be square. I can't see anything on the engine twisted, but I am begginng to think that I need to replace the engine and get a recon with starter motor, as something is wrong with the starter motor or its mounts (something that I cant spot). I bought the boat with only one bolt mounting the starter motor, so the previous owner probably used it for a whil with just the one bolt and might have twisted something.. I hate to spend $2K on a new motor just for a bad starter motor mount. But unless the boat is reliable, my wife will rapidly loose interest in it!!

Gary

 

[Coors]

Re: Correct starter motor

I may be wrong, but I seem to remember that there was a long shaft snout used, back from my GMC days...

 

[superpop]

Re: Correct starter motor

Before throwing the baby out with the bath water and replacing the whole motor I would get the broken bolt out of the block you have and mount the starter up properly and recheck with the right mounting bolts in place. You can do this pretty easy with the motor out of the boat which it looks like you have done already. You should see pretty clearly once the starter is properly installed where the problem lies. You may have the wrong starter but a new one is a few hundred bucks on Ebay for a nice high torque model. I would also replace all seals including the rear main seal as well as an inspection of the manifolds and risers. Once all of this is done reinstall the motor and give it a complete tune up. Anyone who would sell a boat with one of the starter bolts broken probably did very little in the way of maintenance so you need to get everything checked or your wife will hate that boat. Take that from personal experience. Remember, a new block is really only logical if you have low compression or a broken internal, unless you have the bucks to buy a complete bobtail motor with all of the expensive parts already attached, you will still have a lot of other things that could go wrong even on a new motor. Save your money for gas and beer.

 

[thrasher]

Re: Correct starter motor

Sorry Superpop, I guess I haven't been clear enough. There is no broken bolt, the casting that one of the starter motor mounting bolts goes into has broken off (you can actually see it in the photo's), leaving only the second bolt (which is very near to the sump to hold the starter motor in place).
I keep reinstalling the starter motor with the single good bolt to see what is wrong that (the bolt is new and straight) and the starter motor just does not align with the flywheel correctly, but I can't really see why. The second mount that broke off, just allows the starter motor to rotate around the good bolt and that just moves the starter motor gear closer or further away from the flywheel, it doesn't change how far out the starter motor gear can come. I really think I need a different starter motor that allows more travel on the starter gear, to allow full engagement. Once I have that then I can weld up the broken mount and drill + tap the hole to correctly accept the second bolt and hold the starter motor in place. For the minute I do not want to do any welding as the current starter motor is not correctly aligning with the flywheel gear, until that is correct I don't want to do anything else.
I did buy a car starter motor for the engine (before I knew there was a difference for Marine motors) and it is much larger than the Marine starter motor (maybe its a high torque) but it allows the starter gear to move much further and correctly engage the flywheel gear, unfortunately it only has 9 teeth on the starter gear and mercury told me that I needed an 11 tooth (different pitch of teeth). I was/am almost tempted to open the 2 starter motors and put the marine starter gear in the automobile starter and try that.. But I am sure something on the 2 gears would not align!!

So I still feel I am at the same point, It seems that I need a starter motor with a longer throw, then I can fix the second mounting bolt.

So does anyone know if Mercury does offer a long throw and a normal throw starter motor? It would seem to solve my first problem.

Gary

 

[thrasher]

Re: Correct starter motor

Well Mercury service center called me today and told me that I have the wrong starter motor. They can't tell me if the new motor will fix the apparent lack of engagement between the starter motor gear and the flywheel ring gear, but they told me the motor I have is not strong enough to turn my engine over.
As Mercury had given me the wrong part number, they are replacing my motor for free with the correct one..
Hopefully this will solve my problem!! I am very impressed by Mercury's customer support, I have asked them 3 times for support and each time they have replied quickly and been very helpfull.

Fingers crossed the new starter motor will solve my problem!!

Gary

 

[Coors]

Re: Correct starter motor

Well Mercury service center called me today and told me that I have the wrong starter motor.
It seems that there were short, and long snout starters for a couple of years.

 

[Coors]

Re: Correct starter motor

Memory works on occasion.

 

[thrasher]

Re: Correct starter motor

You don't happen to remember the part number for the long snout starter motor do you!!!

Gary

 

[Coors]

Re: Correct starter motor

nope, that was back in the day, about 1971..
sorry, but do remember a pain in the chevy dealership- coulda been in the late 60's