Intermittent no start - LED doing weird stuff (found problem)

My EX has been down for going on 5 weeks now. I rode it on a Friday, had no problems. Charged it the next day and went to go load it to go riding again and the bike would not turn on. I could hear the contacts close and the water pump would turn on, but the LED was off. The dash would come on and it would show neutral, but it wouldn't change gears. If I held the power button to turn it off, the contacts would open, the water pump would turn off, and the LED would flash red once very briefly. Holding the power button to reset the computer wouldn't do anything.

Did the rounds with Stark, without connecting to the bike, they determined it was the VCU. Once I got the VCU, before tearing the bike down, I turned it on and then it was working, annoyingly. At first I was thinking perhaps there was a reset and whatever software glitch it had was fixed - wouldn't be the first time. But I tried turning it on later and it was back to the same thing. So I replaced the VCU and it worked at first, but I came back 5 minutes later and it was doing the same thing.

We then did a zoom meeting - the technician said they didn't see anything wrong in the data. While I was talking to him, I found if I wiggled the VCU (it was still unbolted and just dangling on the harness) the LED would flicker on and off - indicating a harness issue. They shipped me a main harness (but they were out of them in the USA warehouse, so had to get it from Spain).

Today I got the harness and installed it. But still had the same problem. I was able to pinpoint exactly where the problem is - it is the connector that goes to the phone holder, right where it connects at the steering stem, if I put side pressure on the harness just above the connector, the LED flickers.

They are sending out a phone holder and I'm sure that will fix it. But now that I'm looking at it, it isn't surprising that that is where it would fail. The harness flexes right there when you turn the handle bars and that is where all the stress is. I think I'm going to add a short brace to the new harness when I get it, so that the flex isn't happening at the connector. But for others, if you start having weird intermittent problem, try wiggling that harness just above the connector. I'm kind of surprised Stark didn't immediately go there. But thankfully the main harness isn't terribly hard to replace. But losing 6 weeks of riding sucks!

Ya that sounds like a defect that should be a first check not a 6 weeks later customer discovery. I am glad Stark sends out parts (and often times expensive parts) but that has to erode margins and ultimately hurts the business. Spending a little more on QC upfront might catch some of these things before the customer loses 6 weeks of riding.

Chaconne said:

Ya that sounds like a defect that should be a first check not a 6 weeks later customer discovery. I am glad Stark sends out parts (and often times expensive parts) but that has to erode margins and ultimately hurts the business. Spending a little more on QC upfront might catch some of these things before the customer loses 6 weeks of riding.

Click to expand...

Yah, my last problem was the bike wouldn't charge. They sent me a new charger, but by the time it got here, the bike decided to start charging again. I think that one was just a software glitch - never had another problem with it. But it can't be cheap shipping all that stuff back and forth