1972 Mercury 1150 starter frustration

[DVTO2]

My motor was running beautifully today, went about 5 mile out of port to a favorite fishing spot, cut the engine and drifted a bit and then when I went to restart, the starter would spin but not engage. I got us home with the auxiliary and pulled the cover and frame pieces off to get to the starter and it came up when I twisted it by hand, put it back together and it engaged right away. I had this problem last year and took the starter apart to clean it which resolved the problem for until this trip. Is there an obvious problem here? Should I clean it again or just find another starter?

 

[Chris1956]

That symptom is of a dirty starter bendix. A bendix is the twisted steel shaft that allows the starter gear to engage the flywheel. Remove the starter gear and clean the bendix. Now light oil on the bendix.

If that doesn't fix it, perhaps the starter is not spinning fast enough. Clean the battery and starter (including the solenoid) connections and retest.

 

[DVTO2]

thanks!

 

[Barnacle_Bill]

The lugs on the battery cables can corrode inside where you can't see it and cause that problem too. Do a voltage drop test on them to check for that.

 

[DVTO2]

One more thing. The two times this has happened was when the motor had run a good while. When I got it home it still did not engage until I manually twisted it up, but would heat increase the likelihood of the problem somehow?

 

[Silvertip]

If you remove the Bendix from the motor shaft, you will likely see a build-up of crud inside the Bendix. There are small nubs inside that ride in the grooves in the starter shaft. Clean the grooves and the inside of the Bendix and reassemble. Very light machine oil only. No grease! A slow spinning starter and/or a weak battery can also cause the problem.

 

[DVTO2]

I struggled with taking the nut off to remove the bendix and couldn't figure out how to hold the armature without being afraid I would damage it so I just cleaned it still on the shaft. Suggestions there - my hand strength wasn't enough.

Then, #$@^%*, I broke the base that holds the brushes in two. Think epoxy would hold it together?

 

[DavidMoore]

Just under the Bendix there should be flats on the armature shaft to hold it with a wrench whilst you remove the top nut.
No idea on the epoxy​.

Actually scrub that​, I just looked at my old starter motor in the garage. The nut is on the underside of the Bendix itself.

 

[DVTO2]

So I put duck tape on my big vise grips and held the armature to get the nut off and cleaned the grooves. However, the epoxy did not hold the broken brush base together, even for putting it back together. I can get a Sierra rebuild kit for about $50 with the base and new brushes or a new starter for $108 (Protoruq) to about $200 (Sierra and Arco). Any opinions on which way to go?

 

[DavidMoore]

I would take the decision based on the condition of the existing armature, good = rebuild kit, bad new starter. The one you choose is up to you, I can't see in your pocket but generally you get what you pay for. Maybe someone who knows protoruq starters could share there experiences.
If you go for a new one, make sure the No of teeth on the bendix of the new one matches the old one.

 

[DVTO2]

Any other opinions about these starters?

 

[DVTO2]

I am looking at the starters on iboats for the 115 inline and they look a little different. The spring for the gear return is on the top of these starters and mine is underneath. Will it fit in mine. The serial number on my motor is 3369246.

 

[utfyrfytr]

I am no expert on marine starters but as far as I know the spring is usually on top of the bendix gear. The spring holds the gear down so it doesn't vibrate up into the flywheel when the motor is running. Are you sure it wasn't on top of the gear when you removed it to clean the bendix and you may have reassembled it wrong? Another way to be sure is there should have been a washer under the nut securing the bendix gear, that washer is recessed on the bottom so the spring fits inside the recess between the nut and the bendix gear. I hope this helps and I am not leading you astray. Good luck

 

[DVTO2]

No. My spring is definitely underneath, pulling the bendix down.