1250 starter spinning flywheel not turning

[jlincoln]

I had a bad day yesterday, went out started the 1604 that died (seperate post).
Started the 1250 for the season first time. Everything fine for the first 3 times I started it, then I came to a stop on a slight side hill, tried to restart it and just get a hum of the starter spinning, but not engaging the flywheel.
I took the starter off and applied 12V to it and it spins, the gears look O.K. What is the thing that looks like a small rubber like cylinder on the end that I can pull out supposed to do (if anything)?
Thanks for your help.
Not sure why the starter would not engage and turn the flywheel.
Josh

[R Bedell]

Josh:

The "rubber thingy" is a dust boot to keep the debris out of the bendix portion of the starter.

You might want to check the tractor "grounding" and assure that there are good ground connections from the battery to the frame and the frame to the motor.

[klejeune]

May just need some lube on the bendix to get it to kick out. I had to do that to my 1450 a few years back.

[jlincoln]

When I have the starter off the tractor and put 12v to it, the starter spins, just as it does on the tractor. Should the Bendix push out by itself off of the tractor? I do not understand what the Bendix does and how it gets the starter gears to engage the flywheel.
As I said, the starter turns fine on the tractor, the flywheel doesn't turn.
Off the tractor, starter spins, Bendix does not fly out, I can pull it out. Should it fly out and does that somehow get the flywheel to engage in a way that is not intuitive to me.
Thanks and I apologize if this question is too basic. I am not too much of an idiot mechanically, but also not in the ballpark of you guys.

[klejeune]

When you spin the starter it should fly out the bendix and engage the flywheel. When you let off the starter the bendix will retract and disengage the flywheel. Get some dry lube like graphite and lube the shaft the bendix rides on. I like a spray on graphite lube. When the propellant evaporates the graphite stays put.

[Yosemite Sam]

Yeah,

Just what klejeune says, clean the bendix shaft and you may want to go so far as to take the gear off the bendix shaft and clean it (make sure to note how it all comes apart).

Inspect the shaft and the inside of the gear to make sure neither one is messed up.

Clean everything well, lube it and put it back together, make sure the gear moves freely back and forth on the shaft (it should rotate a little as it goes in and out on the shaft).

Before you put the starter back on, make sure the gear pops out when power is applied to the starter and it starts to spin and make sure it goes back when the starter stops spinning. If it doesn't then you may need a new gear or have a problem with the shaft.

When the starter motor turns, the groves or threads on the shaft are such that the speed of the starter turning, pushes the gear outward from the starter motor, this difference in placement of the gear causes it to mesh with the ring gear on the flywheel causing the flywheel to turn, when you let go of the key the starter stops spinning and the gear is pushed back to it's original position by the thin spring further out on the shaft.

Now that should all be as clear as mud for you.

Good luck and let us know how this turnes out.

[jlincoln]

Thanks guys, I will try it as soon as it stops raining.
Just to clarify, my starter is spinning (that much I know), but the gear is not popping out and engaging the flywheel.
What is it that the bendix does (the rubber cylinder thing on the end).
I take it that I will be able to see how the gear comes off after looking at it hard enough?
Thanks for your replies (and patience).
Josh

[wvjon]

The "rubbery thing" is just a dust cover. The bendix is the end of the starter shaft, a spring, nut, and washer. If you wiggle the black rubbery dust cover it will come off, then you will see the nut, washer, spring and twisted splines on the end of the starter shaft. The gear and twisted splines are what you want to clean and lubricate.

Jon

[drysumpjet]

I know this sounds stupid but the gear won't "pop-out" if the battery polarity is backwards since the starter is turning backwards. Also a reversed battery polarity tends to trash the regulator too. Please don't ask me how I know this!!!

[jlincoln]

O.K. I took the starter off and removed the bendix and cleaned and graphited it and it seems to move in and out freely. On the bench when I put 12v to it the Bendix and gear shoot out for about 1/2 second and then go back down. Is that what it is supposed to do? When I put it back in the mower, I thought I would be all set, but I get the same thing. The bendix shoots out a little, but the flywheel doesn't spin (it actually turns about 1/8" each time I turn the starter. What should I do next?
Should the Bendix be kicked out the whole time I have 12V to it?
If so, what might I need to do to make it so?
Thanks,
Josh