94 SP - Starter cranks for a sec then whirs. PITA starting. Bendix?

[Uncle Dirtnap]

Title says it all - One of my skis has always been cranky (no pun intended). It usually would only crank for a second or 2, then just spin the starter, almost as if the bendix only wanted to help out for a revolution or so. I would have to what for the spin to die completly down to try again, or else it would just spin more. Waiting till it was silent would get me another crank or 2 before the spinning noise started again. It seems this 'starter engaging' part of the process has been decreasing over the past few months, till I probably get a revolution from the motor. It's hard to start it that way.

Is that the bendix? I looked at youtube videos, and they don't sounds the same.

-rj

 

[mikidymac]

It could be the bendix but a weak starter that isn't spinning fast or powerful enough can do the same thing.
First check simple things like battery voltage.

 

[AKnarrowback]

X2 on the battery voltage. Put the battrry on a 2 amp charge over night and give it another try.

If that doesn't solve it then pulling the starter and doing some checks is the next step.

One thing to remember, if you think you need a new starter, is to hang on the the original starter. If your starter is white and has a "denso" marking on it DO NOT get rid of it. It is easy to put a new set of brushes into and a used OEM starter is always better than a new aftermarket.

 

[Uncle Dirtnap]

I ended up taking the starter out, cleaned it, polished all the connection, checked the brushes, polished the commutator, greased the bendix shaft, and put it back together. I'm bench testing it with a 50amp battery changer/starter. I apply voltage, it spins, bendix comes out then bendix goes back down, all while it keeps spinning. Should the bendix stay out the whole time I'm applying voltage?

The spiral gear seems fine, as well as the bearings and one-way bendix action. maybe my spring is too strong?

It looks like this:

The folks in the comments are saying the same thing I am- is this good or bad?

-rj

 

[mikidymac]

No, it will go back in once it is up to speed and there is no flywheel to engage from what I recall.

 

[AKnarrowback]

Looks like it is working. The bendix will drop back rather quickly, it stays out when it is meshed with the ring gear until the engine fires. It is the initial spin that throws the bendix out that gives you an indication of how healthy the starter is. It's the whole inertia thing. The starter shaft goes from a stand still to full speed in a split second, the bendix is heavy and doesn't move as fast so the spiral splines of the shaft force the bendix out. After a second the mass in the bendix catches up with the speed of the shaft at which point the spring can push the bendix back in.

Now the fun part, getting it back in the machine.