Modern Vespa

Grinding noise from starter area, refuses to start - I thought maybe a bad brush, so I disassembled the starter motor before checking the Bendix.

The starter motor looks fine, just a bit dirty. It's probably the Bendix.

But now that I've disassembled and cleaned the starter, I have to get the four brushes, located at 12, 3, 6, and 9 o'clock, back on around the commutator. They're spring-loaded, and I can think of no way to simultaneously retract all four so they can slide back on. There's nowhere with a angle to tie them back with thin thread, and I have had no luck trying to push them in and hold them with a toothpick, even a toothpick holding back opposing brushes.

What trick am I missing? This doesn't seem to have been discussed here before.

Greetings:

I've had the same question. This guy seems to have found an elegant way without requiring special tools. Like-sized socket and jeweler's wire to hold the brushes back while you thread on the armature.

I'd seen that. The socket as a spacer is a good idea except that on the starters for the smaller scooters (200cc and smaller, it seems), the armature bearing fits into a blind hole. Even if you manage to fit a socket in it, you can't push it out with the armature!

The other problem is finding "jeweler's wire" that is remotely stiff enough to hold back those springs. Maybe some kind of lockpicking or strapping steel strips could be repurposed...but I don't have those handy.

With an extra set of hands, I did manage to reseat the armature once, by wedging segments of toothpicks horizontally between the copper mesh wire and a small raised plastic nub next to each brush, and maintaining pressure while the commutator was slid into place. I was feeling pretty smug about this until the magnets in the armature casing sucked it back out as I tried to reassemble it. On inspection of the re-disassembled part, many of the brushes had gotten chipped in the process, so I decided to order a complete new starter.

Which is a shame, because there was nothing wrong with it. The brushes were barely worn after 11 years and about 5000 miles, and I didn't mind cleaning and inspecting it even if it wasn't the source of the problem.

The original problem turned out to be maybe a gummed-up, recalcitrant Bendix, but definitely stripped spline teeth in the outer variator gear. So I'm replacing the starter, Bendix, and both sides of the variator (and, galb naggit, the clutch as long as I'm taking this stuff apart). Not sure if or how one failure led to the other. But the situation went from completely normal in my driveway to making a weird grinding sound and absolutely not starting in the Home Depot parking lot.

My experience with these starters is disassembly is the last thing you do. If it doesn't spin when you connect it to a battery then it's probably toast and the only reason to open it is for the autopsy. My Scarabeo 150 starter died and the magnets were all pieces. The replacement cheap Chinese one the magnets just came unglued.

Good advice, Pink. Where the heck were you with all this post morten Quincy wisdom as I was pondering this yesterday afternoon...BEFORE I disassembled an operating starter?

I did manage to get the SOB back together again this evening. It works, but my confidence in it is low so I won't be permanently reinstalling it. It struck me as I was seething over my failure that perhaps a paper clamp (the big black kind, not a paper clip) could be cut with a hacksaw or Dremel into thirds, each with enough clamping strength to hold back one brush. The final brush could be nudged into its holder with the commutator as it was being put into place, and the clamps could be popped out once the whole armature was seated partially or fully inside the brushes.

There may yet be merit to this approach. But as I was making the first cut into the clamp with the hacksaw, my eye fell on the shiny lever parts of the clamp that you use to squeeze the clamp open.

I straightened out the tips of one of the levers, so that it looked more like a plain "V," bent it a bit, and negotiated/bent it into place so that it pushed and held two opposing brushes apart without manual assistance, and without interfering with what would be the commutator's path. I held a third brush in place with a clipped toothpick pressing against the copper mesh wiring, and nudged the fourth brush into place with the commutator as I slid it in.

One try - success! And only one set of hands were needed. Unfortunately I have no photos of this as I did not really expect it to work. But once it did, the trick to placing the magnetic half of the case (or, ahem, taking it off again if you forgot a washer or bracket that goes in there too) without sucking the whole armature right back out of the brushes is to press the armature shaft down using a dowel placed though the magnetic case. Hold the armature in place as the magnetic portion is carefully guided down (or, ahem, up). It also helps to have marked the two halves of the case with a Sharpie before disassembly so the locations of the holes for the long bolts can be properly aligned during reassembly.

The moral of the story, though, is that if the starter spins energetically and the splines on the shaft look good: leave well enough alone. The scooter's problem lies elsewhere.

I've made bigger mistakes than this, for sure. Scooterpartsco's replacement starter motor is $50.

(Edits: for clarity, tidied up my usage of "armature," basically everything inside the case, and "commutator," which refers to the portion of the armature that the brushes touch.)

Ugh. Wish I had seen your post before tearing down my starter. I just got through with this puzzling reassembly process. I used 4 pieces of 1 mm spring wire I had laying around to make miniature clamps, each formed into a "U" shape like a large staple. I clipped each over the starter body to hold each brush fully pressed into its pocket. The armature only just fit over the wire and into its bearing. Then I plucked these little clamps out with needle nose pliers. Not planning on doing that again.

My LX150 starter works but still won't fling the bendix into the variator gear. I have replaced the variator, bendix, relay and battery so hoping a new starter will fix my problem. The old starter has 50K miles on it.

Bill

Hopefully it wasn't engaged the entire time.
Starters wear out.