Wot sputter

[Dooitorbust]

15 Xm 163.. The sled had a hesitation at wot all day today and it pretty well sounds like it's misfiring. Not really a gurgle or bog and not throwing any codes. It was pulling 7900 rpm and the miss comes in about 7600. We pulled the raves and cleaned them but they weren't terrible. Pulled plugs and both were noticeably rich.
I have two suspicions, but I can't put my finger on it.
1. The sled has a brand new MBRP Race can, and I haven't read anything good about them. He had the exact same can last year, but not this particular one. We were thinking of swapping cans as mine is stock and see what happens tomorrow.

2. Possibly a coil but I'm thinking not because both sides are rich.
Does anyone have a testing procedure for coils? Or maybe even a stator? Any other suggestions?
Thanks for any input.

 

[pfi572]

Switch out MBRP first as doesn't cost anything.
Rule that out.

 

[Dooitorbust]

Here's a quick vid of what it's doing. I could see flames shooting out the bottom when it happens. Nothing has changed. Gonna haul my sled off the deck and swap cans next.
https://vimeo.com/195151445

 

[Dooitorbust]

Not the can. Swapped it to a stocker and the same problem exists.
Both coils had 1300 ohms on orange and black.
Running out of ideas.

 

[Dooitorbust]

Maybe the TPS has a flat spot near wide open, causing the rpm to flutter all over the place. Time for a rum..

 

[RGM]

Do you have fresh gas in it?

 

[Dooitorbust]

We ran the same fresh fuel and my T3 haulled azz lol.
I'm guessing it's either TPS or possibly the fuel pressure regulator, but either way it's going in for warranty.
Today he's gonna rent and 850 and we're gonna cut our trip short. Better to have 2 good days than a heli ride out if that thing decides to take a dump.

 

[Teth-Air]

Try unplugging the headlights. If it improves, this can show if there is a low current/voltage problem.

 

[Dooitorbust]

Ok, we'll try that. He's running a mountain addiction hood with headlight delete. The sled has a tiny LED cube light with less draw than stock headlights.

 

[wimpy#1]

15 Xm 163.. The sled had a hesitation at wot all day today and it pretty well sounds like it's misfiring. Not really a gurgle or bog and not throwing any codes. It was pulling 7900 rpm and the miss comes in about 7600. We pulled the raves and cleaned them but they weren't terrible. Pulled plugs and both were noticeably rich.
I have two suspicions, but I can't put my finger on it.
1. The sled has a brand new MBRP Race can, and I haven't read anything good about them. He had the exact same can last year, but not this particular one. We were thinking of swapping cans as mine is stock and see what happens tomorrow.

2. Possibly a coil but I'm thinking not because both sides are rich.
Does anyone have a testing procedure for coils? Or maybe even a stator? Any other suggestions?
Thanks for any input.

Bad reed valves

 

[shaggy338]

Had a 2014 with the same thing dealer spent the season chasing the problem. Turned out to be the fuel pump.

 

[Dooitorbust]

Buddy took it Riverside and they couldn't find anything.
I was thinking reeds as well but it isn't hard starting or bogging on the low end.
Kind of at a loss for now. Sled is officially off warranty so we're pretty well on our own.

 

[Dooitorbust]

Alright, well my buddy took it out for a rip over the Xmas holidays and it turned out to be too light on the primary. Added a couple grams of pin weight to bring it back to clicker 3 and bingo, no more stutter.

 

[SUMMIT TREE]

Yeah, that can do it! Had that issue one time, I forgot I had changed clickers for the trail down, then it was doing the same thing almost like a miss /stutter. I would have thought it would beep at you for hitting over Rev, like it does when I giver too much throttle around home and it bounces off the governor, always goes "beep beep beep!",and displays high Rpm or something like that. But for some reason it doesn't do it when it happens in the mountains, I suspect because it happens slower, compared to when you punch it on hard pack and it hits Rpm almost immediately

 

[Dooitorbust]

Yeah, that can do it! Had that issue one time, I forgot I had changed clickers for the trail down, then it was doing the same thing almost like a miss /stutter. I would have thought it would beep at you for hitting over Rev, like it does when I giver too much throttle around home and it bounces off the governor, always goes "beep beep beep!",and displays high Rpm or something like that. But for some reason it doesn't do it when it happens in the mountains, I suspect because it happens slower, compared to when you punch it on hard pack and it hits Rpm almost immediately

Kicking my azz for not thinking about it on the mountain. My boosted XP would do it on the trail up if I jammed on it before elevation. Won't happen again, let me tell you. At least it was a simple fix.