I don't see this anywhere on the internet, so I thought I'd do a quick write up.
After receiving my Stark I was having issues with it hard cutting after riding hard and applying full throttle. It was quite dangerous on jumps on a moto track. After I updated the software, I started getting a "water pump error" when I went from standby to ride mode. My debug tips:
1. You should hear a water pump "whirring" noise when you turn the bike on. You should also hear a faint sound of water running, because the water pump is running coolant through the hoses/radiator.
2. If you don't hear those sounds, the water pump isn't running. Check the water pump electrical connector:
If you hear the pump running, but you are still getting the "water pump error" or having hard cuts after hard riding, you will need to bleed the coolant system. It's at 15:47 in the Stark "Remove and Install the Power Train Unit - Stark VARG"
Water Pump Error:
Funny that this was the main problem on the first run of Altas
Shocking.
What's next.
What's next ? Hhhmmm who knows. Could be lots of things, maybe you should start a poll lol. I'm going to go with a circuit board problem. I'll say a bad circuit board giving false error codes causing owners to replace good parts and still have the same problem.
Joking aside cutting out is no joke on a motocross bike.
The Stark wouldn't be the first bike to have cutting out issues...
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Would all of those examples be brand new bikes, just delivered , like the Stark ?
Or older bikes , with some wear & tear.
Also, am I right in understanding this is a system shut down happening ?
I would have thought cutting out or stalling would have been almost impossible in a properly functioning electric bike
Didn't a connector issue cause problems with a few STAR Yamaha bikes?
Electric bikes may want to limit power to say 20 hp if there's an error like that detected for safety and warning.
The OP has stated an electrical connector wasn't fully seated, which is caused by an assemble error at the factory.
Stark is a new company, quality control issues will occur.
Stark has some extremely detailed instruction videos.
Sarcasm? I’m not an electric bike fan because I like the noise smell of gas bike but this is crazy if not being sarcastic.
One thing is that Japanese electronics quality has always been better than the euro stuff, with that I mean connectors , harnesses, control units. I already have the experience with KTM and euro cars. So if I ever get e bike it will be made in Japan , less chance to get clapped out because of bike problem !
I work with ECU's, digital dashes, electronic throttle bodies etc, everyday for over 15 years, I respectfully disagree, at least as far as modern German, Austrian, Polish, British components go they are perfectly good. When we get into French, I may change my tune 😂 Even German designed but South American produced Bosch / TE stuff is perfectly good.
The best connectors out there generally American, British or any given country's mil spec stuff.
The Japanese are perfectly good too, I'm certainly not saying they are bad because I agree with you they definitely aren't.
LOL have you ever owned a Ford or a Harley Davidson?
Aren't they the same thing?
Yep that must be a skilled labor job.
It is kinda interesting how much of a big deal connector mates and de-mates are in the space industry. I always wondered if other industries made such a big deal about it , sounds like maybe not.
Had/have the same problem. Stark promptly sent a new pump. While in transit I decided to take this one off so I could just put the new one in as it arrives and save some time. I took the cap off (the bolted one where all the hoses go in) to separate the pump in 2 parts. After inspecting with my finger I found that an aluminium fin/part was present which probably prevented the pump from spinning. The metal part which looks like it came off from the radiator is like 4cm (1.5 inch) to maybe 2mm wide.
I cleaned everything, put the pump back (made sure it spins with a 12V separate source), made sure it spins when the bike is on (it does) and filled with coolant back again. I can hear some pump noises when turning on the bike and vibrations on the whole system but I do not seem to hear liquid passing through the system (it has a distinct noise like a silent waterfall if you will).
After a few seconds, the error reappears on the display so yeah, not sure if the new pump will do anything. I fear that parts of the radiator fell into the system and is blocking much more than what I found.
ya'hear'dat
it's solved
Yes I have owned a HD....
I had two issues in 11 years with it. Brake light switch and a tranny shaft bearing went bad. Damn good/reliable bike.
Pit Row
I have a water pump error as well. Checked the connector per Stark tech I talked to yesterday morning. Still the same error, the connector is sending 12v, and the motor is reading 8k ohms (for whatever that is worth).
Still waiting for Stark to reply and send the new pump. I think I'll take apart my water pump in the meantime to see if I have any blockage as well.
Did you bleed the coolant system? I was still getting the error after I connected the water pump. After I bled the coolant the error went away and hasn’t happened again (almost 50 hours on bike now)
I did not bleed the system, but I can't hear the water pump and the Stark tech said he was reading an intermittent signal. I assume he was looking at the Amp draw, so the pump probably isn't even spinning.
When I first rode the bike in my backyard, I could hear the water pump running, so it was working initially.
Alright, I disassembled the water pump, powered it on and re-assembled. Error is gone, but the pump sounds unusually loud and changes noise when I tilt the bike on its side. I bleed for air multiple times.
I thought I heard a small *tink* noise when I disassembled the water pump. Maybe a metal spacer fell out? I only saw a clip on metal washer when I opened it up further. Not sure if anyone can tell me if the clip is the only loose part inside. See picture of clip below.
I don't have a root cause for the pump failure, so maybe the excess noise is just a bad bearing that caused the pump to seize in the first place?
I can see the same clips on my pumps. I have 2 of them now but that error won't go away no matter what. Maybe it needs a remote reset from stark?
Thank you for confirming!
My error persisted until I primed the pump. Not sure if there's a separate flow meter or if there's just a range of amps the VCU detects for proper operation.
Right back at you. You need to keep loosening the pump cap and tightening it again until all the air escapes out of the loop. You will hear the pump getting on higher load when that happens. Keep bleeding and let it run, also keep topping up the coolant.
I figured out the root cause of my water pump error. It was dirt in the coolant getting into the rotor and scrapping/stopping the pump. Unfortunately, I figured this out after replacing the water pump and scraping the new one up as well!
I just finished sanding the rotor and inner motor body for the original pump and bled the system. When the bike was new, I swear I didn't even hear the water pump except for a slight water bubbling sound. Now it definitely sounds like a motor running and I can hear it across a quite room. How loud are other Stark water pumps?
I found out the loud noise was due to the small air gap remaining in the radiator. Filling up the radiator until the very top of the threads and then screwing in the plug removed air from the system and the water pump is running quiet as new.
So heads up, if anyone damages the electric water pump due to debris (mine stopped running), you can sand the rotor and inner hub, flush the coolant several times, and the water pump will work like new.
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