starter gear drops when motor starts to fire

[teslaman]

This past weekend when I started my motor, the start gear would fall when the motor would start to fire. Although it doesn't seem to be a big deal now, I'm afraid that it may get worse later on and put a strain on my starter motor as it revs up due to the lack of load when the grear drops. Of course, I'm quick to stop cranking when this occurs, but there is a second or two when the starter has no load on it as it is turning.

I have an 115hp 73 V4 Johnson 115ESL73 and have purchased Sierra # 18-5679 to replace the gear, spring, and whatever else.

Should this replacement be the solution to my problem? The gear on the starter does show a little wear but nothing alarming. Does anyone have any tips or suggestions about other possible problems or issues I may encounter when installing the replacement?

 

[jtexas]

Re: starter gear drops when motor starts to fire

It's designed to function like that.

What happens is, when the engine fires, it spins the bendix faster than the motor shaft, which causes it (bendix) to screw itself back down...it's designed this way so that the engine won't be able to spin the starter motor faster than it could spin itself.

The problem is with your engine not starting.

 

[red boat]

Re: starter gear drops when motor starts to fire

teslaman, that starter gear is operating as it is supposed to. As soon as the spinning of the flywheel exceeds the speed of the starter gear it throws the starter gear down. The replacement of the starter gear will do anything because it does not seem as you have a problem.

 

[red boat]

Re: starter gear drops when motor starts to fire

jtexas, you obviously type faster than I do!! lol

 

[teslaman]

Re: starter gear drops when motor starts to fire

Right, I absolutely understand that, but this never happened in the past -- and the engine starts the same now as it always did. Maybe I'm just paying more attention to it now, but I think the gear is slipping just a bit early.

I had a mechanic with me and he said the same thing. I guess I'll just watch it and replace it if it gets worse.

 

[tashasdaddy]

Re: starter gear drops when motor starts to fire

is your battery full charged? weak current can cause this.

 

[teslaman]

Re: starter gear drops when motor starts to fire

When I cranked it up this past weekend the battery was fully charged. I checked the battery voltage with a meter and it appeared to be fine at around 12.5V.

 

[R.Johnson]

Re: starter gear drops when motor starts to fire

A 12.5 battery is half discharged.

 

[jtexas]

Re: starter gear drops when motor starts to fire

...and the engine starts the same now as it always did...

if that were the case, you wouldn't have need to post a question... 8)

in any case, it's not a faulty bendix...either
1. the starter's not spinning fast as it used to, or
2. the engine's getting harder to start.

if it's #1, then either
a. weak battery, or
b. bad cables/connectors, or
c. weak starter motor.

keep us posted...

 

[excalibur-oc]

Re: starter gear drops when motor starts to fire

I had EXACTLY the same thing happen on my 1984 175.
i went to a small shop to replace the bendix as well however the guy had to take it off a brand new starter for me. When I showed him the old bendix he told me there was nothing wrong with it & suspected my starter was getting week.
for the $100 extra I took the new starter & put it on right in his parking lot.
I cannot remember my motor starting as well as it does now.
My vote is with the weak/tired starter
Good Luck

 

[Texasmark]

Re: starter gear drops when motor starts to fire

I'll support the half discharged battery at 12.5 and that it is the reason why you see it now. Get a battery (if it won't charge up and hold it), not a bendix or starter. I use 12.75 for fully charged 24 hrs after any charging attempt. Some on here use 12.85. Best way is to use a hydrometer and read the specific gravity for the ambient temp at the time of the measurement.

Mark