[twerth]

I need a little help with an intermittent problem with my 2005 999. A few times over the last several months, I'll be riding down the highway (75-80 mph) and my bike will completely shut off. After coasting ~100 yards, it fires back up and runs normally again. No error codes on the dash or with GuzziDiag, and aside from this issue, it runs beautifully.

At first I suspected the crank position sensor, so I replaced it. As usual, it ran fine for a month or two, but then did it again yesterday. With no codes, I'm at a loss where to start. Any ideas would be appreciated.

 

[FourRings]

Check the fuel pump relay behind the battery box. Also, check the continuity of the wires leading to the fuel pump.

Fuel Flange Wires | ca-cycleworks.com

 

[twerth]

You might be onto something. I was thinking electrical because of how abruptly it dies, but a total lack of fuel pressure might do the same thing. I'll check it out. Thanks.

 

[jahjah]

When you say the bike totally shuts off, are you really saying that the engine stops running? Other electrical appears as normal so you are decelerating in gear and the dash appears as though the engine is making power? After you coast, are you recycling the ignition key? Are you starting by starter or coasting compression?

 

[twerth]

When you say the bike totally shuts off, are you really saying that the engine stops running? Other electrical appears as normal so you are decelerating in gear and the dash appears as though the engine is making power? After you coast, are you recycling the ignition key? Are you starting by starter or coasting compression?

Yes to your first two questions, although I can't say for certain the dash appears normal. When this happens, I'm consumed with finding a way off the highway and looking out for cars trying to clobber me. 100 yards at highway speed only takes a few seconds, so I haven't had a chance to cycle the key. The bike restarts by coasting compression. Thanks.

 

[jahjah]

It sounds like FourRings may be on the right track. It would be interesting to note if you get a yellow check engine light but I understand that is no time to scan the dash. Since you replaced the crank pos sensor, and one overheating coil wouldn't stop you, short of the ECU rebooting on it's own, fuel pressure may be your answer. The Fuel Pump relay is a cheap item but not sure that is a common failure mode, as you describe it. Also, does not sound like a filter issue. A faulty fuel pressure regulator that is on the edge of providing enough pressure may cause some sputtering before stopping. The problem I have is that you describe a multi incident event that is identical. If the fuel pump wiring is the problem, they chance it would restart exactly at the same time seems remote to me.
So, what would tickle the ECU to reboot? Possible a poor power connection or ground or it is failing as a component. Possible a problem communicating with the dash? Don't know. A sensor issue, I would not think would reboot the ECU.
If you have a helmet cam, you might look long enough at the dash next time it happens to record the status.
Sorry, no solid solution.

Are there any wires coming from the fuel pressure regulator on your 2005 999 bike?

 

[twerth]

A lot of good stuff here jahjah! I'll try to answer your questions more or less in order. First off though, if the ECU is suspect there's one thing I should mention. The PO had installed a Power Commander. It's always run great, so I haven't monkeyed with it. Maybe this or one of it's connections is the problem?

I should also note that the duration of the outage isn't exact. Roughly 100 yards (3-4 seconds), but one time I was able to get out of the lane of traffic (still moving ~50 mph) before it refired, and the last time seemed relatively short. So duration isn't exactly the same each time, but never long enough to bring me to a stop. Still seems to rule out fuel pump wiring in my mind.

I replaced the fuel filter when I got the bike about seven months ago. The tank was pretty clean, and I'm careful with what I put in it. I don't think the filter is the problem.

I've had quite a bit of the accessories and wiring apart during the course of cleaning and detailing the bike since I've had it. The PO was not very meticulous about maintenance. I've done belts and valves and a dozen other minor items to get it back up to snuff. Maybe i didn't get one of the connections tight? That would seem to fall into the same category as pump wiring though.

Aside from checking all the wiring harness connections, I'm thinking I might just replace the fuel pump relay and see what happens. It may be a couple of months before I know, but worth a shot.

Finally, I don't have a helmet cam, but if it happens again, I'll make an effort to check the dash and see what it's doing. I think if it was something weird I'd have noticed, but when you're in panic mode...

Thanks again for your help. Greatly appreciated.

 

[davy.j]

I had that short duration sudden cutout on my 853, cured it by reducing the cps air gap.

So long as there is running clearance in it cold it's ok as it increases with heat and that was what caused my issue.
Brad Black on here gave me the tip to reduce the gap.

 

[xracer]

I'd be removing the power commander FIRST.

 

[twerth]

I had that short duration sudden cutout on my 853, cured it by reducing the cps air gap.

So long as there is running clearance in it cold it's ok as it increases with heat and that was what caused my issue.
Brad Black on here gave me the tip to reduce the gap.

That would be easy and cheap to try. I might start there. Thanks.

 

[xracer]

not so easy on a 999, water pump gets in the way. and you have to have shims on hand. easier to unplug the powercommander and go for a ride. symtoms don't sound like to much gap.

 

[twerth]

not so easy on a 999, water pump gets in the way. and you have to have shims on hand. easier to unplug the powercommander and go for a ride. symtoms don't sound like to much gap.

Removing the CPS is a bear due to the water pump as you noted, but shims aren't so bad. They can be R&Red without removing the CPS. Just need to undo the bolt. I just had it all apart a month ago, so I'm pretty certain about that.

Unplugging the PC might be a good idea. My bike has a full Zard exhaust installed, so I suspect the PC was added to account for that. May end up needing to remap the ECU, but worth a try. If I remember correctly, I'll need to get inside the airbox to unplug it. A bit of a PIA, but doable.

 

[xracer]

Unplugs from the outside. Takes a few seconds.

 

[davy.j]

not so easy on a 999, water pump gets in the way. and you have to have shims on hand. easier to unplug the powercommander and go for a ride. symptoms don't sound like to much gap.

Sounds just like it to me Rob, mine was in spec, lower number and motor would just cut dead like it hit the limiter, hard stop and then unlikely as it might sound, re-fire several seconds later as the motor cooled just a tiny fraction to reduce the gap to a working level.
Tried two different pickups, same result.
Called Brad and he told me to try reducing the gap to just a few thou which I did and the problem went away and never returned.
(Thanks again Brad, you saved me lots of $ and time chasing that one)
I'd still check the PC like you suggest but easy enough to shim the pickup down first and not mess with the map.
Sims are easy enough to make, each page from a pocket notebook is 2.5 thou and A4 80gsm is 4.5 thou.

As far as faulty relays go I have had that issue too but always got backfires as it died first.

 

[xracer]

Morning Davy. From what I interpreted from his post his problem wasn't symptomatic of the cps air gap.
I had two powercommanders fail and show similar symptoms to what he has. I didn't suggest he monkey with the map.

 

[twerth]

I unplugged the Power Commander last night and went for a ride. Honestly, I can't tell a difference with or without it. I'll ride it a bit more and check the plugs and fuel mileage, but I think I'll end up removing the PC all together.

I'll ride it for a while and see if the problem reoccurs. It may take a while, but I'll keep you posted either way. I really appreciate the help!!