[mcromo44]

I looked in every folder of the dropbox and can't find it, is it in there?

What exactly are you looking for?

 

[mcromo44]

I looked in every folder of the dropbox and can't find it, is it in there?

It's still there exactly where I put it and here is the path:
WT_Shared/919/Power Commander Files/1 McRom44 Compilation/919 specific Cold Start Issue

 

[Islandboy]

I was going to jump in and say the cold start update was in the drop box but I see your in good hands(mcromo) so I'll just bugger off!
Good luck ditch.

 

[Ditch]

Got it, thought the power commander file would be just maps

Thanks guys

 

[Darth_Firebolt]

I just put a power commander on my bike and did this diode mod. It's 85F outside now, so we'll see how it does in 6 months or so.

 

[robtharalson]

This is a revision of my analysis of the failure. It seemed wrong that regardless of the magnitude of the back EMF it would not be sufficient to make the relay drop out in and of itself. There had to be another factor, so I hooked up my oscilloscope and watched the various circuits in action and it became obvious that the side stand switch was the culprit. it turns out side stand switch is not actually a mechanical switch, instead there is a circuit that uses a magnetic sensor, called a hall effect transistor, to control the ground to the engine stop relay. When the back EMF is generated it temporarily cuts off the signal to the relay, dropping it out.

It's a fine point, but I am finally sure of the exact cause.

Rob

 

[mcromo44]

This is a revision of my analysis of the failure. It seemed wrong that regardless of the magnitude of the back EMF it would not be sufficient to make the relay drop out in and of itself. There had to be another factor, so I hooked up my oscilloscope and watched the various circuits in action and it became obvious that the side stand switch was the culprit. it turns out side stand switch is not actually a mechanical switch, instead there is a circuit that uses a magnetic sensor, called a hall effect transistor, to control the ground to the engine stop relay. When the back EMF is generated it temporarily cuts off the signal to the relay, dropping it out.

It's a fine point, but I am finally sure of the exact cause.

Rob

Rob,
Are you essentially saying that the diode mod is not even part of the solution and that it's purely defective side stand position triggering that is at play?
If so, why only in cold weather?
(I'm thinking 32 F wouldn't be a factor for the magnetism, and I don't know anywhere near enough to even ponder the Hall effect aspect)

 

[robtharalson]

Rob,
Are you essentially saying that the diode mod is not even part of the solution and that it's purely defective side stand position triggering that is at play?
If so, why only in cold weather?
(I'm thinking 32 F wouldn't be a factor for the magnetism, and I don't know anywhere near enough to even ponder the Hall effect aspect)

Actually, I miswrote: it's the bank angle sensor.
The diode is actually the solution. The root cause is Hall effect sensors are sensitive to voltage fluctuations and the back EMF from the starter relay is causing the circuit to drop out. Since it is not possible to break into the sensor the shunting diode is the best cure.

As I said it's a fine point, but I could not leave the cure alone until the etiology of the malfunction made itself apparent.

Rob

 

[mcromo44]

Actually, I miswrote: it's the bank angle sensor.
The diode is actually the solution. The root cause is Hall effect sensors are sensitive to voltage fluctuations and the back EMF from the starter relay is causing the circuit to drop out. Since it is not possible to break into the sensor the shunting diode is the best cure.

As I said it's a fine point, but I could not leave the cure alone until the etiology of the malfunction made itself apparent.

Rob

Rob, thanks but the above raises more questions.
I get it that the diode remains the solution, in terms of the 919.
What's throwing me off is the reference to the bank angle sensor.
Is it possible that the reference the bank angle sensor was in terms being the culprit of TSmith's 2007 Tuono stalling issue?
And that you checked the BAS on your 919 by the scope and found something?
Thanks, gotta be sure, aye!
Your oscilloscope work sounds like the present, and my assumpt

 

[robtharalson]

Rob, thanks but the above raises more questions.
I get it that the diode remains the solution, in terms of the 919.
What's throwing me off is the reference to the bank angle sensor.
Is it possible that the reference the bank angle sensor was in terms being the culprit of TSmith's 2007 Tuono stalling issue?
And that you checked the BAS on your 919 by the scope and found something?
Thanks, gotta be sure, aye!
Your oscilloscope work sounds like the present, and my assumpt

In Todd's case it was the bank angle sensor which was mounted incorrectly, not it's circuitry. This is a perfect example of having and using the right equipment: where the DVOM did not indicate a problem in the power line to the stop relay the 'scope did, though it was so fast it was difficult to see. It's brevity notwithstanding it is enough to disrupt the PCIII. Hopefully Dynojet went to input capacitors with Mil Spec ratings.

Rob

 

[mcromo44]

Rob,
I think I have it now.
The DVOM does not reveal all, and the O'scope does.
The 919 Bank Angle Sensor is involved with the cold start issue, not the side stand, and the diode is the solution.
IF I have it right, then I remain baffled as how low ambient temperature is involved with the Bank Angle Sensor's having an effect when it's cold outside.
Look forward to you advice.

 

[Islandboy]

Just curious. Could the bank angle sensor be disconnected? And if so would it be dangerous to do so.
For what it's worth the diode fix has worked a treat for my bike.
Thanks again Rob.

 

[robtharalson]

Rob,
I think I have it now.
The DVOM does not reveal all, and the O'scope does.
The 919 Bank Angle Sensor is involved with the cold start issue, not the side stand, and the diode is the solution.
IF I have it right, then I remain baffled as how low ambient temperature is involved with the Bank Angle Sensor's having an effect when it's cold outside.
Look forward to you advice.

The temperature range of most semiconductors is considerably wider than wet electrolytic capacitors, particularly in the lower temp range. The problem is on Dynojet's end of the deal, and when informed of the fix I'm quite sure their EE's buckled down to cure it, invariably costing a bundle to spec out revised circuit boards and BOM's. As to the progressive nature of the onset, I can only guess.

Just curious. Could the bank angle sensor be disconnected? And if so would it be dangerous to do so.
For what it's worth the diode fix has worked a treat for my bike.
Thanks again Rob.

You're welcome. Yes, the BAS can be bypassed, but unlike carbs which on it's side the fuel runs away from the jets and the motor dies, with fuel injection if there is a tipover with greater than half a tank of fuel the motor will happily run until the complete lack of oil pressure destroys all the main and rod bearings. That is one of the lessons I learned without sacrificing my own machinery.

Rob

 

[TheRig]

Edit

Spoke too soon this mod didn’t work

 

[TheRig]

…