My gen2 started dying when coasting with the clutch pulled...

[Magerly666]

Here is a video of the issue:

What you don't see is when it manifests itself over the course of the ride. The 1st instance was about 4 mins in, then it didn't happen again until about 15mins...after I had been in traffic and lots of pulls on the clutch. Then it did it two times in 30 seconds and then did fine on the way home.

Thanks MaxMidnight, I will read up on that!

 

[Magerly666]

After putting it in diagnostic mode, it showed a Fault Code of 12... Crankshaft Position Sensor. I can't be sure that code wasn't already there, since it keeps them in memory until they are deleted.

I will delete it from the memory and try and get the issue to happen again, then check if the fault code is there again.

 

[02GF74]

Now that sounds promising, as the symptoms you describe tie in with an electrical component failing.

 

[MaxMidnight]

After putting it in diagnostic mode, it showed a Fault Code of 12... Crankshaft Position Sensor. I can't be sure that code wasn't already there, since it keeps them in memory until they are deleted.

I will delete it from the memory and try and get the issue to happen again, then check if the fault code is there again.

That's a good point and deleting it is a good idea.

 

[Magerly666]

Got it to die multiple times, but unfortunately it did not have a fault code stored in memory when I returned home.

I got it to die once by pulling the clutch, then popping the clutch, then pulling it again and let it engine brake...it always seems like if the rpms drop to around 500, then it will die...they are normally around 1000 when I pull in the clutch to coast and it is running fine.

Could it be something in the ECU that sees the rpms too low and shuts it off?

 

[OKCVmax]

My bike has been doing the exact same thing. This is the first time I've heard anyone else have the same issue. I'll have to check my fault codes and see what mine says.

 

[02GF74]

Could it be something in the ECU that sees the rpms too low and shuts it off?

I cannot think of any reason why ECU would want to shut down engine at very low RPM; surely when trying to start the engine, RPM are less than 500 before it fires?

The issue is the engine dying when I am coasting with the clutch pulled in.
Unless I kept the rpms up, it would just die again when I pulled the clutch in.

Let's go back to this.
Let's say you are riding with revs around 2,000. You pull clutch in but don't touch the brake - what happens?

Engine should keep on running but drop down to idle revs, typically around 1,000. If revs keep dropping until engine stalls, then there is a problem, I don't know the cause but would suspect a sensor.

Are you not able to take it to a Yamaha dealer for investigation? - the only alternative would be to start replacing sensors one at a time until the problem goes away such as crank and cam sensor or hope someone else has had the exact problem and resolved it.

 

[digin150]

Not sure what year you’re vmax is , some of the early production 2009 had a similar problem there was a recall on part of the wiring harness ,throttle position sensor? Took mine in for the recall even though mine didn’t have any problems

 

[Lunatic]

Clutch in has a throttle map separate from the gears

 

[Magerly666]

It is a 2011.

Let's say you are riding with revs around 2,000. You pull clutch in but don't touch the brake - what happens?

When I pull in the clutch, normally, the rpms drop to 1000-ish. When I noticed it is about to die (like in the video), the rpms drop to 500-ish. That seems to be a reoccurring theme... It is like something has caused the idle rpms to drop to 500-ish.

I can sometimes induce the issue by pulling clutch, popping it, then let it engine brake a couple seconds, then pulling the clutch again...but not everytime.

It is weird, because it is a random issue that just happens periodically. One day it happened 5 mins into my ride and died like 3x..then didn't do it again for the rest of the ride. Next ride didn't do it at all, but then the next it did it 3 separate times in 15mins... very random this is!

Engine should keep on running but drop down to idle revs, typically around 1,000. If revs keep dropping until engine stalls, then there is a problem, I don't know the cause but would suspect a sensor.

It drops down to 500 idle rpms,, instead of 1000...then quickly drops to 0. If that makes sense.

I appreciate all the replies...it helps to get different perspectives.

 

[MileHayabusa]

Have you tested your TPS? It sounds suspiciously like it might be going bad... I would guess the factory service manual would have the proper readings for what a good one should test out at.

 

[Magerly666]

Have you tested your TPS? It sounds suspiciously like it might be going bad... I would guess the factory service manual would have the proper readings for what a good one should test out at.

The TPS sensor is one of the modules you can test in the ECU diagnostic mode. Here is what it says should be the readings:

D:13 Throttle position sensor Meter
signal 2 Display
• Fully closed position | 15–16 | Check with throttle valves fully closed.
• Fully opened position | 97–102 | Check with throttle valves fully open.

The meter display (the DIAG mode display) should read 15 - 16, but mine reads 14. I am not sure what to make of that.

==================================================================================
On the ride into work this morning, it died about 10 minutes into the ride. This time it died when I pulled the clutch in...didn't drop to 500 rpms then die...it straight up dropped from whatever rpms I was at to dead! It did this about 3 times in a row. So I decided to do something I hadn't done while moving, I turned the key off and on and then popped the clutch to get it started. It stopped dying and the rpms were dropping back to 1000 like normal when the clutch was pulled. Previously, I only turned the key off and on when I was completely stopped.

This is pointing me into thinking there is something ECU related, otherwise why would powering off and back on solve the issue?

 

[Lunatic]

What flash do you have?

 

[OKCVmax]

Not to hijack - but - just tried starting my bike, and it won't won't a thing. Click but no crank. Odometer is replaced by a big #12. Kinda thinking we both might have crank position sensor problems.

 

[MaxMidnight]

Not to hijack - but - just tried starting my bike, and it won't won't a thing. Click but no crank. Odometer is replaced by a big #12. Kinda thinking we both might have crank position sensor problems.

That's telling you the ECU isn't getting a signal; check the basics first i.e. connections or pinched/ broken wires.
The sensor resistance should read 192–288 Ω at 20 °C (68 °F)

 

[OKCVmax]

That's telling you the ECU isn't getting a signal; check the basics first i.e. connections or pinched/ broken wires.
The sensor resistance should read 192–288 Ω at 20 °C (68 °F)

I dont have any pinched wires, I do have a reflash, PCV, and quickshifter. I'll do another check. I've had it 'click' with no crank before, but it did that even bone stock. I figured it was a sensor for one of the safeties, or the starter. I've never seen the 12 code replace my odometer before.
I did check fault codes as well, it had a few... 12 was also one of them. I reset it and ill see what happens, I haven't been able to ride it lately but in the past 3 rides I've had it died on me everytime, more than once.

 

[Lunatic]

Brushes are probably shot in the starter.

 

[MaxMidnight]

Brushes are probably shot in the starter.

If that was the case why is the ECU indicating there is no signal from the crank positions sensor?
Unless this bike has had a lot of starts I doubt that the starter bushes would be the problem.

 

[Eric Levitz]

Has this issue been resolved, I am still having an almost identical issue as described, although not very often...
Pull in the clutch while costing and it dies ...

 

[jlewis02]

My 2015 with k&n filter,guru voodoo exhaust map,voodoo exhaust,PCV with auto tune does the same thing I noticed it at the drag strip when I was cooling the clutch that it just dies no warning at all when I pull the clutch in. It does this in every gear.