Mon Nov 15, 2021 2:41 pm

Member
Due Stellae Automatica
Joined: 25 Oct 2021
Posts: 35
Location: Austin TX
 
Member
Due Stellae Automatica
Joined: 25 Oct 2021
Posts: 35
Location: Austin TX
Mon Nov 15, 2021 2:41 pm linkquote
Moving this discussion over here from the NSM area, for more visibility and in search of a wider range of input.

Long story real short: I'm a motorcycle guy, but I was given a free basketcase scooter in hundreds of pieces, a Yamaha Vino 125, and in short order I had it running and roadworthy. Then my wife gave it a try and she fell in love with it, so I painted it and made it hers. But I had the bug, and I wanted my own scooter, so I got another basketcase with high hopes, this 2014 Stella Automatic.



When I got it, it was in mid-repair, and I bought it from the 2nd owner who had only had it a week and had absolutely no information. It was missing some parts that indicated the variator cover had been off, like the center stand spring anchor. Otherwise it read like something in the midst of diagnosing a starting issue: there was no starter solenoid, the original battery was there and totally shot, the spark plug was loose in the hole, the ignition coil was floating around in the engine bay. But it was basically intact and had a straight body and looked like it had only been laid down once with minimal damages, so I bought it for cheap.

I bought a battery and managed to get a generic starter solenoid fitted. Since it had horrible old gas in it, I drained the fuel and pulled the carb, cleaned it and reset it to factory adjustment as best as I could. There was a vacuum hose missing here and there so I fixed what I could and removed the air injection stuff, plugged the holes. Then I went to start it and began to discover what was really wrong.

Push the start button and you just hear the starter spin freely. I took the variator cover off and discovered the starter bendix had several chipped teeth. I figured this just was not engaging so I ordered a new one along with a handful of other parts that were missing. Once I got this stuff in, I put it all together, and lo and behold, once I managed to get the fuel reservoir full and the carb primed, it started and ran. And I rode it for about a week. Then it went very south and left me stranded, sounded like the starter spinning freely again.

This time I took it apart and it turned out the teeth on variator fixed drive face were sheared off. Further investigation shows that there was a spacer missing, which made it impossible to get the drive face tightened because the nut would bottom on the threaded portion of the drive shaft before it clamped the pulley.



I also noticed there is really bad wear on the bendix-side of the starter ring gear teeth on this pulley. So I need a new pulley, but they are not available.

I decided to solve the unreplaceable stripped pulley problem by using a combination of metal epoxy and roll pins to fix the kickstart drive plate to the pulley. And then eventually I solved the missing spacer problem with a couple of 15mmx20mmx0.8mm washers between the locknut washer and the kickstart drive plate. You can read the whole story in the other thread if you care to.



So now the core problem is that the starter will only engage about one in 10 tries. The scooter is not usable, basically. I got stranded on it when it killed the battery before it would start. I won't ride it anywhere unless the destination is back home now.

I have no good solutions on the table to fix this starting issue. Once the scoot is started, it runs and drives just fine. I need a new outer drive face, but SIP are out of them, and they seem to be the only place on earth who might one day have one. They have had them on order and they are over a two months overdue for delivery. I am not holding my breath. I am now considering trying one of two solutions, maybe both.

My current theory is that the wear on the starter ring gear is causing the bendix to not engage. It just kind of bounces off. So my idea right now is to remove the pressed-on ring gear and reverse it, putting the unworn outer edge towards the inside. Maybe this will buy me some time. So that's solution #1.

Solution #2 is maybe a better long term plan, since I need a potential supply of additional drive face pulleys, which warrants an engineering task. A pre-leader Vespa ET4 150 pulley has the right starter ring gear dimensions, 69 teeth, but from pictures, the eyeball test tells me the splined center interface is too large for the Stella. I measured the outer spline diameter to be about 14.6mm, and it's an 18 spline interface on the Stella. The ET4 pulley has an 18 spline interface, but it looks to be bigger than 14.6mm. Also, there's a recess for a spacer on the inside of this pulley, so a spacer or bushing would have to be fit there anyway. Both of these problems are solved in the same way, which is to get a sleeve/bushing/bearing which fits the gap between the pulley spline interface and the crankshaft, and fit another spacer/bushing into the recess to take up the rest of the space. Then I can solve the lack of spline interface the same way as I have now, which is to bond/pin a kickstart drive plate to the new pulley. So I plan to order one of these ET4 pulleys and give it a shot. But they come from China and will take until 2022 to get here, so I need a short term solution first.

The next problem was that I couldn't kickstart it. The kickstarter was siezed in the outward position when I got it, so I wound up whacking it with a hammer to move it, then soaking the pivot pin in WD40 to get it to loosen up enough that the kickstarter could be folded in and out. Then when I tried to kickstart it that day that I ran the battery dead trying to start it, the kickstarter folded back on itself because this pivot pin had slipped. Turns out that pin is a pressed in part. My penetrating oil loosened it up, I guess. So today I put a 3/32" roll pin through this pivot and the kickstart lever where it fits to keep it in place, and now I can kickstart it. It would likely take all day to kickstart it if it was cold, but if you start it once, it'll kickstart pretty easily subsequently.

My detective skills now are telling me that what likely happened is the PO cracked open the variator cover to replace the belt, likely at the 10K miles mark or so, and lost the spacer that's now missing, without knowing it. Then when it was all together, the drive face could wobble on the shaft, causing intermittent non-engagement with the bendix which eventually broke some teeth. I'm guessing the PO just described this as "it won't start" and started down the normal diagnostic of ruling out electrical start stuff and lost interest in the project. Then I got the thing, didn't know about this, and wound up riding it and eventually ruined the drive face running it loose.

There are a hundred other issues with the scooter. The seat cover was shot, so I made another one, which at least doesn't have holes in it, but it's not pretty. But I didn't want to invest in cosmetic changes until I got it to run reliably. The front brake light switch was stuck in the "on" position, and when I unstuck it, now it will only do "off". So I have a new switch on order, again from China and will be a while getting here. No matter, since now the tail light and brake light on the whole are not working, which I guess is likely a bad ground at the light assembly.

In the long run, I can't get along with the nutty angle the brake levers are mounted, and I also don't like the single mirror and the way it's mounted. Plus, I don't want to retrain myself to use turn signals on the wrong side, and I'm sure my wife will never ride this thing if the controls are not what she is used to. So I want to modify it to use regular motorbike hand controls, which means cutting off the cast right side control pod and finding a way to mount clip-on type handlebar tubes to the headset and fit ordinary hand controls. That'll fix all of my control issues at once.

And it has some bodywork issues, but the main thing is I need to find some matching paint. I can probably hammer and dolly the front fender into shape enough, but it needs paint on that part as well as the cowls.

Once this is all sorted out, I will deal with the normal stuff... headlight bulb, needs new tires, etc. But right now I just want it to be usable. It's a really cool bike and I hope to make it work long term.

There's someone local who has what looks like a potential parts bike donor 2014 Stella Automatic that I might be able to pick up for just a bit more than the cost of the pulley I need. So there's a chance I can rob the parts from a parts bike and be back in business in no time.

The biggest problem with this whole thing is that parts are just so hard to find for this thing. I hate to see a 90% functional, good scooter get trashed just over a $40 part. Plus, I like it, and I am not known for giving up.
Tue Nov 16, 2021 11:00 am

Member
Due Stellae Automatica
Joined: 25 Oct 2021
Posts: 35
Location: Austin TX
 
Member
Due Stellae Automatica
Joined: 25 Oct 2021
Posts: 35
Location: Austin TX
Tue Nov 16, 2021 11:00 am linkquote
Took the tail light lens off, pulled the reflector so I could inspect the wiring, and the brake light started working. Tail light doesn't work. Oddly enough, -0.5VDC on the plugs. Awesome!

Also the turn signals quit working. It seems every time I take the headset cover off and put it back, it pinches some wires and electric stuff goes all wonky. This is a horrible design! I need to get in there with a roll of heat shrink, zip ties and adhesive tie-downs to rework this, but it's not worth it until I redo the controls. I'll make it limp for now. This thing sure does have classic Italian reliability!

I'm negotiating hard on a parts bike, <1700 miles on it, likely good variator, but hasn't been run for 3 years so I'm not hopeful the engine is going to run. Missing the cowls, carburetor, battery, other stuff. I'm likely to go check it out and if it has good compression, the electric starter engages and turns the motor over, then I'll probably make a deal and bring it home. We'll see. I wouldn't mind having an entire spare motor here, especially a low-miles engine, so I can take my time and rebuild it and then just swap it.
Wed Nov 17, 2021 6:56 am

Member
Due Stellae Automatica
Joined: 25 Oct 2021
Posts: 35
Location: Austin TX
 
Member
Due Stellae Automatica
Joined: 25 Oct 2021
Posts: 35
Location: Austin TX
Wed Nov 17, 2021 6:56 am linkquote
Today I went out to try to do something about the starter ring pulley.

Turns out the pulley is only worn on around 30% of the perimeter, and the teeth are beveled on the back side, so I decided to just align it so it would line up the good teeth most of the time and leave it.

Put it all together, and it electric-starts about 75% of the time, the first time. When it doesn't, it just spins the starter, I am guessing because the bendix is aligned with the worn portion of the starter ring gear. I can put the kickstarter out and kick it once or twice to realign the engine and then it fires right up. So I think I have it in shape to ride.
Wed Nov 17, 2021 7:01 am

Ossessionato
VSX, Stella 177, Stella 150, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 3476
Location: Staten Island, NY
 
Ossessionato
VSX, Stella 177, Stella 150, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 3476
Location: Staten Island, NY
Wed Nov 17, 2021 7:04 am

Ossessionato
VSX, Stella 177, Stella 150, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 3476
Location: Staten Island, NY
 
Ossessionato
VSX, Stella 177, Stella 150, VNX1T, V9B1T
Joined: 20 Jul 2018
Posts: 3476
Location: Staten Island, NY
Wed Nov 17, 2021 7:13 am

Member
Due Stellae Automatica
Joined: 25 Oct 2021
Posts: 35
Location: Austin TX
 
Member
Due Stellae Automatica
Joined: 25 Oct 2021
Posts: 35
Location: Austin TX
Wed Nov 17, 2021 7:13 am linkquote
Thanks! In my research, I've seen these. The JCOSTA part available both at Tasso and SIP does not include the outer pulley face, according to SIP. So it's not a "complete" variator, despite what the description says.

There are two different variators for these bikes, one for the '13-14 models and one for the '15+. I know this because I bought one for the '15+ and it does not fit. So I have one of those new sets like on the SIP page sitting in my garage. That pulley has 75 teeth and is 132mm diameter with a 13mm/19-spline axle. I need 69-tooth, 123mm with 14mm/18-spline. The part I need is this one:

https://www.sip-scootershop.com/en/product/v-belt-pulley-lml-front_11304580

It's two months overdue "in arrival" at SIP and Tasso has removed it from their catalog. I don't expect it to actually ever arrive at SIP. I think this part is NLA forever, which is why I need to find a way to make a non-LML part work.

The part I am considering is this one:

https://www.aliexpress.com/item/33058159469.html?spm=a2g0o.productlist.0.0.7ebc2645wJNSFc&algo_pvid=52856307-211d-4d03-b19a-8edadcca1ff6&algo_exp_id=52856307-211d-4d03-b19a-8edadcca1ff6-1&pdp_ext_f=%7B%22sku_id%22%3A%2267484258260%22%7D

It's a pulley for a pre-leader ET4. Anyone here have one of these that they can measure the spline diameter? I'm likely to order one even if the splines are not the right size, but it'd be awesome if it would just fit and work. The starter ring gear is the right size.
Tue Nov 23, 2021 6:56 am

Member
Due Stellae Automatica
Joined: 25 Oct 2021
Posts: 35
Location: Austin TX
 
Member
Due Stellae Automatica
Joined: 25 Oct 2021
Posts: 35
Location: Austin TX
Tue Nov 23, 2021 6:56 am linkquote
This project is about to take an unexpected turn.

Currently the Stella is in usable, but annoying, condition. It will start every time, with varying amounts of effort. It it hasn't been run in a day or two then it takes a lot of cranking and a little bit of throttle to get it started, but it e-starts and runs great. If it is warm, restarts are a cinch but sometimes you have to use the kickstarter to turn the motor a few degrees if the bad part of the starter gear is lined up.

I am very close to declaring this project "complete". That's because this weekend I am going to pick up what is basically a NOS 2014 Stella Auto just like this one but with only 8 original miles on it. It's been sitting for 7+ years, indoors, and is in basically mint, unused condition. It'll take typical long-sitting-bike reconditioning, but the hardest part of the new project will likely be getting it registered.

Once I can get the new one registered and verified working reliably, I'll sell the old one as-is., with full disclosure to the buyer, they need either to be comfortable with kickstarting it part of the time or get a new pulley by hook or crook. I don't need the money from selling it, and I might even give it away, but I don't have room to store a scooter I am not going to ride.

The good news is, I have proof one of these Stellautos can run 10K+ miles. So I should have 10K of usability left. Considering I have two other motorcycles, I figure I can go at least a decade before hitting that 10K mark.
Thu Dec 02, 2021 11:58 am

Member
Due Stellae Automatica
Joined: 25 Oct 2021
Posts: 35
Location: Austin TX
 
Member
Due Stellae Automatica
Joined: 25 Oct 2021
Posts: 35
Location: Austin TX
Thu Dec 02, 2021 11:58 am linkquote
This project is officially "complete". I have a new-to-me, nearly-new 2014 Stella Automatic in hand now and after a bit of bringup work for a bike that's been sitting unused for 7 years, it runs. So I am going to eventually say goodbye to the project Stella.

I really had hoped this underdog would eventually prevail, but nope. I did have to swipe the ECU from the old one since the ECU on the new one was broken (no spark), but Genuine is sending me a new ECU at no charge, so the old one will be back in running, hard-to-start condition so I can move it on to another victim after next week.

So long, old scoot. I didn't even run a whole tank of gas through it.
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