Bike dying after it warms up

[sooprvylyn]

Hoping someone might have the answer for me. I have a k1100rs that I have converted over to motogadget m-unit blue. Everything works fine for the first hour+ of any ride I do, and then I start to get some power stutters, and eventually the bike dies. If I turn off the power switch and turn it back on, the bike starts right up and runs for a bit more before dying again. The lights on the bike all still work when it dies, so it's not something with the m-unit. All the wires to the m-unit are properly connected and the lights work as they should. I'm not getting any faults in the m-unit when this happens, so it seems to be something related to ignition system, the ecu, something else on the bike. It might be something related to the outside temp as the issue only started to happen as the temps outside have climbed.  Any ideas?

[Laitch]

Do all the instrument cluster functions shut down as you're coasting to a stop?

[sooprvylyn]

The lunchbox has been deleted. There is a motogadget motoscope mini on it now. I will say that the brake light, headlight and turn signals stay on, but those all run thru the m-unit.

[frankenduck]

Ignition amp:

https://www.motobrick.com/index.php?topic=3061.0

[sooprvylyn]

Ignition amp:

https://www.motobrick.com/index.php?topic=3061.0

I had wondered if this might be it. I did mount my ignition amp to a new alloy subframe without the goop. I have a tube of it I ordered and was planning to put it on once I work up the energy to do what's needed to access it(it requires removing most of my electrons because of where I relocated it). 

You think thats the likely culprit?

[Laitch]

Ignition amp:
https://www.motobrick.com/index.php?topic=3061.0

You think thats the likely culprit?

[frankenduck]

I had wondered if this might be it. I did mount my ignition amp to a new alloy subframe without the goop. I have a tube of it I ordered and was planning to put it on once I work up the energy to do what's needed to access it(it requires removing most of my electrons because of where I relocated it). 

You think thats the likely culprit?

First thing I looked for after reading your post was to see if your K1100 was a 93.

[sooprvylyn]

Haha, I hope so.  Doesn't seem that my symptoms match the description in thay link that closely. I get a couple shudders after like an hour or more, then it shuts off. If I turn the bike off then on, it starts right up and runs for a bit before dying again.  Does that sound right for this being rhe issue?

[sooprvylyn]

First thing I looked for after reading your post was to see if your K1100 was a 93.

So it's a common thing on the 93? 

[frankenduck]

So it's a common thing on the 93?

Yes, also on the earlier K100RS4V and K1 which also have the ignition amp.  94+ K1100s have a different Motronic and ignition system without an ignition amp.

[sooprvylyn]

Ah, ok. Well thank you for helping out. I had run into this a few months ago and thought "but my bike works fine and I didn't use heatsink grease"....before the temps really heated up. I didn't know about it when I was building, but purchased some grease when I read that in anticipation of potential problems. Looks like I'll be needing it. Will update after I have a chance to do the application whether the problem is resolved or continues.

[Laitch]

In the attached illustration, note the surface area of the bracket onto which the heat sink assembly is attached. That bracket is where heat goes to die. It's likely yours should be attached to a surface with similar capacity to dissipate heat. Please update us with the field trials.

[sooprvylyn]

Thanks laitch. Luckily I did mount my unit to a large sheet of bare aluminum that also holds my ecu and m unit. There should be zero problem getting the paste to do what it's supposed to do

Excuse the spaghetti below....it actually a lot better than it looks.

[frankenduck]

That's nothing. I could out-spaghetti you any day.

[frankenduck]

That's right under the tank where it gets pretty hot - that aluminum sheet might even warm up the ignition amp.

[sooprvylyn]

Possible I guess. I get a shitload of airflow under the tank after deleting the airbox tho...and the amp is more under the seat than the tank.  Still possible tho I guess.

[frankenduck]

I was looking at it "backwards" and had the orientation wrong. My bad.

[sooprvylyn]

All good, a little hard to see the orientation in the photo.  Thays a rear fender you see on the far left.

[sooprvylyn]

Resurrecting this thread:

Ok, so I put thermal paste on my IC amp and I am still having problems.

Symptoms:

I can ride for an hour or more without problems.  When I start it back up after a break to continue riding, it will go for a bit and then it will suddenly lose power. It wont start again until I turn the bike off and then back on again. Once I start it again it will run for a few more minutes before dying again. I can get it started right away every time as long as I turn the bike off first and back on.

Ideas?

I'm thinking it could still potentially be the IC amp as the mounting location is under the seat in close proximity to all the res of my electronics, and airflow might not be the greatest, and I'm sure there is a little heat from the fan blowing up there. Is this the likely problem? I rode it in this location for about 6 mpnths before the problems started, but they definitely started during the summer and it gets fairly hot here in austin. It's not a particularly hot day today, but I did have it parked in the sun for about 30 minutes before resuming my ride and getting the problems

Any other possible issues I should look into?

[Laitch]

Faulty Hall sensors or Hall sensor connectors could be possibilities.

[sooprvylyn]

Thanks Laitch,
After research on hall effects problems I strongly think this is a likely culprit. From what I've read they tend to go bad around 70-80k Mike's, right where my bikes engine is. Also the symptoms I read are pretty much in line with what I'm experiencing. I'm gonna get a new one and replace it and see if that sorts me out. I think the ICU is probably OK because I did feel it after the bike died to see how warm it was and it didn't feel particularly warm, and neither did the metal plate on the opposite side of where it was mounted.

[Laitch]

After research on hall effects problems I strongly think this is a likely culprit. From what I've read they tend to go bad around 70-80k . . .

Some might, but most work tens of thousands longer than that in bikes ridden and not neglected. There's a test that you can try; you probably read about it during your research. Give it a try.

[sooprvylyn]

Yessir

[Kaos]

This could have more reasons than the above mentioned problems/solutions. ESP. when using a motogadget.

Which wiring diagram was the foundation for your m-unit?
Do the following wires share the same relay(s) or the same powersource: ecu, ignitioncoil wires,  fan, fuelpump or a combination of these

the several other possible options to the above are:
option 1, you either have separated power cables running from the battery 1 for the m unit with fuse and and other(s) to relays.
If this is the case its most likely overdrawing your battery when your fan starts, or even worse when your fan is locked up.  then it draws way to much voltage and your bike will shut down.
This can also happen with other relay connected components. (sounds most logic when it happens after about a hour and starting afterwards)

option 2, no fuse (40 amp) and are overdrawing the battery to run insufficient voltage to the ecu.
This can also happen with Insufficient resistance (thickness) for the powercable. For example Noco powersport batteries or other lifePo4 batteries have overdraw protection which will result in exactly your symptoms.

Option 3 A wiring issue (most likely the alternator blue wire) <- if this were the case you'd have to charge your battery btw.
this needs to be connected to a 12volt (or less with resistors) outlet to charge your battery properly. Your m-unit would still give out power to the attached leds cause they draw very low voltage.

Option 4 Your grounding cables might have an issue or insufficient grounding or thickness for whatever happens after a hour, with yet again the possibillity of your fan starting.

Therse a pretty easy way to test overdrawing and insufficient anything, just have a spare fuse ready because you may blow your fuse when its wiring or drawing power related.
Set your bike in neutral. Set your blinkers to position lights at a higher percentage open the throttle and start your bike with throttle opened, not fully, 1/3 half maybe.
If your leds start to flash or when you blow the fuse you have to change the wiring routing.
After this you could additionally test it with your bike in neutral and fully opening the throttle with a quick wrist flick, if lights starts flashing it probably of the 4 options with 3 being the least likely.

[sooprvylyn]

I have actually tracked it down to Aux 1 output on the m.unit.  THe previous issue has actually been resolved, but the new issue has IDENTICAL symptoms.  I can ride just fine til the bike warms up, and the day warms up, then the bike dies....turn the bike off and on again and starts right up.  Then dies again shortly after.  The m.unit Blue sends a message to my app that says AUX 1 overamperage...and of course this trips the fuse, which tells my ecu the kick stand is down, and the bike dies.

Aux 1 is feeding my fan relay, my fuel relay and, and my ECU(kick stand POS I think).  I am about 90% sure its something fan related.

I've been a little lazy lately with the bench testing as I am also adding in a catch can, and working on a fuel cooler, and replacing my too small puke can, but i have the entire guts off the bike and can connect the m.unit and relays to a battery and try grounding the fan relay switch(after connecting a light to the output) to see if the aux 1 over-amperage warning gets triggered.

This is 100% a new problem after I cleaned up my wires.  I probably connected something in the fan relay wrong.  I didn't have the overamperage warnings until I redid the wiring at the same time I thermal pasted my ignition unit.  I have date stamps on the warnings and every single one since I rewired has the overamperage warning...and no warning prior to this