Stella 4t Won't Run

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Joined: Fri Jul 22, 2016 3:10 pm

Stella 4t Won't Run

Postby strangelimey » Fri Jul 22, 2016 3:25 pm

I got a new Stella 150 4t last year and it ran beautifully.
However, it started to have clutch issues. When I eased out the clutch lever, there was no friction point; it would just bite and the bike would jerk into motion. I figured the fact that it has a sidecar might be the cause so I took it to the local scooter shop and they installed a better quality clutch. Riding away from the shop was beautiful as it eased nicely into each gear.

Then it broke down half way home. It just stopped, as if it were out of gas.

So, I took it back to the shop where they insisted it was just a coincidence and the best thing to do was to bypass the silly evap system that Genuine had put on it so it could be sold in California. They did that and I rode off. It broke down on the way from the shop again. I called and they told me that they never wanted to see me again! I'd been polite the whole time so this was a bit of a shock.

Anyway, I took it to another shop and they spent 2 months and $500 trying to figure out why it would start up and run for about 30 seconds and then just die. Each subsequent attempt, it would run for less time before dying.

They gave up and gave me my bike back (but still changed me $500) and I took it home. Then I hired a local mechanic to come to my house once a week and diagnose it with me so I could learn.

We put in a Polini big bore kit, a Polini 22mm carburetor, changed the CDI, the battery, the spark plug and the coil.

Same result. It runs for a few seconds and then dies.

We took the sparkplug out, grounded it, turned the lights out and fired the starter up. We saw that the plug would spark for a few seconds and then just stop.

So, what could cause that? The only thing I can think at this point is that the regulator is shot or that the ignition is cutting out for some reason.

Anyone have any ideas? This was supposed to be a cheap ride for getting around town but I've spent lots of money on it and I still don't have a working vehicle...

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Re: Stella 4t Won't Run

Postby Areomyst » Sun Jul 24, 2016 8:45 am

Hi there, and welcome to Scooter Invasion!

First off, I hate to hear anytime someone gets stuck by a repair shop. That's a really good way for the shop to leave a bitter taste in your mouth not only about them, but about scootering in general. The fact that you were charged that much money for someone to NOT fix your problem is ludicrous. I'm very sorry to hear about that.

If your ignition is cutting out on you, it could be a couple of different things. You could have a bad stator, CDI, coil, or a combination. You could even have a bad wire or connection somewhere. I know on the 2-stroke Stellas, there were sometimes problems with the kill switch wiring where it tunneled through the headset to the kill switch. If there is a wire with the insulator worn off, and that wire gets to arcing to ground, it will kill the ignition.

In my workshop, I use an Ignitionmate diagnostic tester for issues like this - but you don't need super expensive stuff to try to narrow down the problem. Often times, a simple test light will suffice for giving you a good idea on what's going on with the ignition system. I think the first thing I would try, is to locate the kill wire on the CDI, and see how it runs from there. From there, you can perform the same test you did before (grounding the plug) until the spark goes away. Then you can work your way upstream with a test light to find out which components are getting power/ignition signals.
Unfortunately, I'm not sure of all the wiring on that model. If a wiring diagram is not available then tracing the wires/colors is usually not terribly difficult.

Please keep us posted on what you run into! I haven't looked yet, but if I manage to find a service manual for your scoot, I'll let you know!

"The more a man learns, the more he realizes how little he knows."

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Re: Stella 4t Won't Run

Postby strangelimey » Mon Jul 25, 2016 2:34 pm

Thanks, Josh.
I was thinking along the same lines. I'll use my multi-meter and see if I can find what's going on with the wiring.
I have the service manual with a full wiring diagram so it shouldn't be too difficult...

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