494 Starter motor

[B17overhead]

Anyone have a good used or new Rotax 494 starter motor for sale?

I'm embarrassed to say that I don't know how to properly find one from the seller's descriptions on Ebay. They always seem to sell them by sled year and model and I have no idea what to look for.

Thanks for any help on this!

[TDI PILOT]

Call Pat, he has a few of these starters and other 494 parts for sale.

(810-441-9608

[B17overhead]

Thanks!

[cory mcleod]

For future reference, the models/years of sleds that came with 494s is posted at F500.us. Agree that it is frustrating trying to find parts for our engines without the sled info. Like going to the big box auto parts stores and trying to get the 18 yo employee to find a generic part without the "year, make and model."

Cory

[B17overhead]

I didn't know that ref list was there on that site, Cory. Thanks!
I suppose 18 years isn't so bad when you realize that the Cortina's that 1600 Ford motors came in are about 52 years old at this point.

[cory mcleod]

Considering that I'm averaging 2-3 race weekends per starter, yours should be in the hall of fame!

[Sully]

Considering that I'm averaging 2-3 race weekends per starter, yours should be in the hall of fame!

What fails on your starters?

[B17overhead]

What fails on your starters?

I've never had a failure myself, but i'll take a guess it is engine vibration shaking the insulation off the windings and then they short out. This is a problem peculiar to a high vibration, high heat environment. Someone I know who races a small 2 cylinder 260 HP 2-stroke in AM had to pot the stationary windings in high heat epoxy to get his starters to live.

[cory mcleod]

Sometimes random things happen, like the long bolts that hold the thing together back out or I accidentally twist the power lead stud too much when trying to tighten the cable, but most of the time they just stop working. My engine is a 593 and I use aftermarket starters, so the quality is not OEM. Q told me that the ring gear on the Polaris primary has a slightly smaller ID than the Rotax ring gear, so the bendix on the starter doesn't fully mesh with the ring gear and that causes premature starter failure. At his recommendation, I now have 8/100 taken off the mounting tabs of each starter. Not sure yet whether it's making a difference in life span.

[B17overhead]

Cory,
Wouldn't one connect only pinion/Bendix/ring gear uneven wear to a too-light mesh? I suppose if it were the other way around where the mesh were too deep (too tight) there might be extra heat in the motor electronics from extra load.

I'm still inclined to go with heat + vibration as the real killers.

If your starters just stop working and don't melt your kill switch when you try to crank, I'd also be more inclined to look for an open connection- like a fatigue cracked through connection. Supporting all the wires better that go point to point inside so they don't vibrate might be worth doing. Or at least damping the vibration with blobs of RTV on the wires like one does on Exhaust springs.
-Chuck