HELP Power jerking after Drivetrain replacement (GEN2)

[Karinshi]

I'll summarize my case in case anyone has experienced something similar.

My Varg EX wouldn't charge past 78%, and Stark decided to have the motor replaced through my nearest dealer. The dealer replaced the complete drivetrain and the bike charged to 100% without any issues. It seemed to be fixed, but when we went to test it, it started jerking, the power cuts out, as if the throttle were misconfigured and couldn't communicate properly with the bike or the VCU.

The bike starts, and everything seems fine, but it accelerates and brakes on its own constantly; it's like it has square wheels. You know the feeling I mean, right?

Does anyone know what it could be, besides a faulty motor, faulty VCU, or battery? I already know those. But everything else was fine except the motor; other components shouldn't be failing now.

My dealer doesn't know what it could be; it's probably a software issue, not a mechanical/hardware problem.

As I write this, he just sent me a message saying he's been asking Stark and that more parts need to be replaced, but he won't tell me which ones. He said at least three weeks without the bike.

On top of that, I don't know how this dealer got the official certification because he's literally the guy who runs a motocross track where he rents ICE, Surron, and Stark bikes. He doesn't speak the local language, and his customer service is terrible. He doesn't explain things. When I went to drop off the bike, he left it parked in the sun in a place where tons of people, vans, and trucks passed by, and it could easily be stolen. I asked if we could keep it in the workshop or somewhere safer, and he said rudely, "If it gets stolen, I'll buy you another one." "Do you want me to sign a paper or something?"

Anyway...

 

[Bodo]

When you accelerate, you draw more amps. What seems initially fine on lower power draw will stutter if a high power connection is mechanically loose.

 

[Chaconne]

I'll summarize my case in case anyone has experienced something similar.

My Varg EX wouldn't charge past 78%, and Stark decided to have the motor replaced through my nearest dealer. The dealer replaced the complete drivetrain and the bike charged to 100% without any issues. It seemed to be fixed, but when we went to test it, it started jerking, the power cuts out, as if the throttle were misconfigured and couldn't communicate properly with the bike or the VCU.

The bike starts, and everything seems fine, but it accelerates and brakes on its own constantly; it's like it has square wheels. You know the feeling I mean, right?

Does anyone know what it could be, besides a faulty motor, faulty VCU, or battery? I already know those. But everything else was fine except the motor; other components shouldn't be failing now.

My dealer doesn't know what it could be; it's probably a software issue, not a mechanical/hardware problem.

As I write this, he just sent me a message saying he's been asking Stark and that more parts need to be replaced, but he won't tell me which ones. He said at least three weeks without the bike.

On top of that, I don't know how this dealer got the official certification because he's literally the guy who runs a motocross track where he rents ICE, Surron, and Stark bikes. He doesn't speak the local language, and his customer service is terrible. He doesn't explain things. When I went to drop off the bike, he left it parked in the sun in a place where tons of people, vans, and trucks passed by, and it could easily be stolen. I asked if we could keep it in the workshop or somewhere safer, and he said rudely, "If it gets stolen, I'll buy you another one." "Do you want me to sign a paper or something?"

Anyway...

It is probably a stupid question but did you do a firmware update after the install?

 

[Lost]

Why the motor needed changing for a battery that couldn't charge to 100% is confusing to begin with, why that worked... more so.

Most obvious would be the motor is duff, as that's the only thing changed.

But I'd go through the wiring first to see everything he's done is correct and secure.

Have you tried setting regen to 0%? Any change?

Stark really needs to set up a proper master tech program to stop these sorts of problems coming out of the dealers. The amount of "I took my bike to a dealer with XYZ and X months later it's still not fixed" posts I've seen isn't ideal, especially as Stark wants you to send it to the dealer ever 40 hours...

 

[Chaconne]

Why the motor needed changing for a battery that couldn't charge to 100% is confusing to begin with, why that worked... more so.

Most obvious would be the motor is duff, as that's the only thing changed.

But I'd go through the wiring first to see everything he's done is correct and secure.

Have you tried setting regen to 0%? Any change?

Stark really needs to set up a proper master tech program to stop these sorts of problems coming out of the dealers. The amount of "I took my bike to a dealer with XYZ and X months later it's still not fixed" posts I've seen isn't ideal, especially as Stark wants you to send it to the dealer ever 40 hours...

It sounds like a safety circuit. These are often typically controlled in software and prevent over driving or use in an unsafe manner.

Alternatively, I wonder if some circuit was left jumpered from the factory that forces it to some safe mode?

 

[Karinshi]

It is probably a stupid question but did you do a firmware update after the install?

yes, the bike requested automatically, seems that the bike detected the new drivetrain unit and request that... Although it was updated to the same version, there wasn't actually a new update

 

[Karinshi]

Why the motor needed changing for a battery that couldn't charge to 100% is confusing to begin with, why that worked... more so.

Most obvious would be the motor is duff, as that's the only thing changed.

But I'd go through the wiring first to see everything he's done is correct and secure.

Have you tried setting regen to 0%? Any change?

Stark really needs to set up a proper master tech program to stop these sorts of problems coming out of the dealers. The amount of "I took my bike to a dealer with XYZ and X months later it's still not fixed" posts I've seen isn't ideal, especially as Stark wants you to send it to the dealer ever 40 hours...

I followed several Stark recommendations. At first, they told me the battery cells were unbalanced. Then they told me to do slow charges at 0.3kW from 20% to 100%. That didn't fix it. We had a video call, and they remotely accessed the motorcycle. Nothing worked. The motorcycle would stop charging and shut off when it reached 78%. They told me it was the inverter, which is part of the same unit as the motor and can't be replaced separately. And now, after the dealer replaced it, we're running into this problem. The thing is, don't expect my dealer to be super professional. He's a former professional motocross rider who now runs a Surron and Stark rental company at a track. He treats you terribly and is annoyed because I didn't buy the motorcycle from him but through the Stark website. He has a mechanic who does the repairs, and they have no idea what they're doing. I don't know how Stark made them an official dealer. It's the first Varg they've repaired. I was the first on my island (Tenerife) to own one. There are only four on the whole island: mine, my best friend's, and two he rents out at the racetrack. They're inexperienced.

And no, i didnt try 0% regen, i dont know if he did, i didnt thought of telling him that on site. He was complaining that he doesn't have a number to call Stark to resolve problems on the fly; he has to wait for mail, and that's very time-consuming. Master tech program for dealers is very necessary. Thank you

Edit: When i was on the dealer i was looking for the wiring, and seems pretty good, the wiring is so simple that i think its difficult to messed up, i dont think is a wiring problem

 

[Karinshi]

It sounds like a safety circuit. These are often typically controlled in software and prevent over driving or use in an unsafe manner.

Alternatively, I wonder if some circuit was left jumpered from the factory that forces it to some safe mode?

i dont know man... i got the bike in april, 3.000km no problem on the drivetrain, only that the battery couldn't charge above 78% but stark saids the battery is good and healthy, it was the inverter that caused the problem, but now with the new drivetrain/inverter it cuts off power and power stutters... seems like a VCU problem to me, thanks for the help and opinions... nothing we can really do here, just wait for the dealer who is talking to stark and wait if they see the real problem

THIS FORUM IS AWESOME, THANK YOU EVERYBODY FOR THE IMPLICATION TO HELP OTHERS, IF YOU GUYS NEED SOMETHING YOU CAN COUNT ON ME

LOVE

 

[Karinshi]

UPDATE:

Stark just send me this email, i didnt reach them, they told me this automatically wich is nice, its in spanish, i will upload the screenshot and translate it.

Hi Carmelo,

Today we had a call with the dealer to connect to your motorcycle and were able to diagnose a problem that had previously escaped us. It appears to be the cause of the issues you've been having with the bike.
We're preparing a parts order to send to the dealer as soon as possible, which will resolve the problem, and you'll be able to pick up your motorcycle then.

I understand this situation isn't ideal, and I want you to know that we're looking into compensating you with an extended warranty for the entire period your motorcycle has been out of service.

If you have any questions, please let us know.

Best regards,

Stark Future Team




Seems that some more parts needs to be replaced, i think the VCU but i dont know what could be the other one, i dont think they will replace the battery, altough ill be happy, new battery is always good hahaha

They take care of me very well from the first day, i can't complain on the customer service.

 

[Bodo]

Interesting that they won't reveal what they diagnosed in the second attempt, and that they don't commit to a timeline

 

[Karinshi]

Interesting that they won't reveal what they diagnosed in the second attempt, and that they don't commit to a timeline

do you mean a timeline for the extended warranty? I don't know how they're going to apply the warranty extension. Maybe they'll just add the time the bike will be out of of use for the repair? In this case, 2-3 weeks... I don't know... or they'll probably extend it for another 6 months, since I've had this problem of not being able to use 100% of the range for 6 months now. In the end, I've only had 78% available, which is less than the MX 1.0 with the 6.5kWh battery.

 

[Lost]

Sooo Stark have so far:
Suggested cell imbalance.
Sent a power train - fixing the charging issue but creating a new one.
Sending more parts (unknown currently).

This reminds me of a back yard mechanic who just throws parts at a car until it's fixed.

(Also, Tenerifes local dealer should be avoided at all costs)

When you know the outcome, can you update as these sorts of topics will be useful in 4-5 years when they are out of warranty.

 

[Chaconne]

Good luck sorry you have had so many issues.

Stark went from no dealers to anybody's sister can be a dealer I guess. My dealer is a well known KTM dealer who I had purchased KTMs from in the past. From the sounds of some of the stories I guess I was lucky there.

 

[Karinshi]

Sooo Stark have so far:
Suggested cell imbalance.
Sent a power train - fixing the charging issue but creating a new one.
Sending more parts (unknown currently).

This reminds me of a back yard mechanic who just throws parts at a car until it's fixed.

(Also, Tenerifes local dealer should be avoided at all costs)

When you know the outcome, can you update as these sorts of topics will be useful in 4-5 years when they are out of warranty.

Yes, new drivetrain fix the charging issue, so it seems it wasnt the battery but now create the power cut issue wich can be the new drivetrain aswell... so manyy things to troubleshoot and test... now they are sending unkown parts (i think new VCU and maybe cables, i dont think ill get a new battery) lets see, i will update

also, Tenerife Local dealer should be avoided but we only have this one for all the archipelago which consist in 7 islands... send it to peninsula iberica will be more time without the bike and i dont think Stark will cover the shipping costs...

Anyway, thank you all

 

[Bodo]

Tenerife Local

Nice, you can ride all year - that makes up for it!

 

[Karinshi]

Nice, you can ride all year - that makes up for it!

View attachment 15173

yes man, we have one of the best climates in the world, and millions of tourist visit us each year. But politicians are closing a lot of trails for motor vehicles, we are very limited now... the motocross circuit is very good at least but for enduro we are f****

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this is the circuit where he rent the Vargs for an absurd price i think

He is "Fabian Künnemann" maybe someone knows who he is

Price on selling Vargs are very cheap because in here we got very low taxes

 

[AL_V]

do you mean a timeline for the extended warranty? I don't know how they're going to apply the warranty extension. Maybe they'll just add the time the bike will be out of of use for the repair? In this case, 2-3 weeks... I don't know... or they'll probably extend it for another 6 months, since I've had this problem of not being able to use 100% of the range for 6 months now. In the end, I've only had 78% available, which is less than the MX 1.0 with the 6.5kWh battery.

They will just extend your current warranty by the amount of time you didn't have access to your bike.
Mine was down for about a month for the dealer to replace the battery, son they added a month to my original warranty.