'23 Khaos Matryx Slash Boost, since day 1 I've been experiencing this annoying issue I refer to as cruise control... Seems like whenever I back off the throttle the sled keeps wanting to go. This is similar to the issues I've experienced on the AXYS, but that was due to the throttle block freezing up. I ruled that out on the Boost when it kept happening on the trail right after unloading from the truck. The throttle cable doesn't seem to be binding or getting caught anywhere, this seems more like an ECU issue. Anyone else dealt with this? What's the fix?
Cruise Control on Boost
- Thread starter snowracer21
- Start date
I would be surprized if the throttle body boot was cracked since day 1 but they are known to crack and leak and idle high due to being lean. Make sure you are not experiencing a lean condition like this.
It’s a very common issue. Some people say it goes away if you add the belt deflection bolt in the secondary, some say it’s the ecu. Polaris knows about it and won’t do anything about it because they “consider it normal operating condition? Could get sketchy in the trees.
I wonder if the blow off valve is not opening when it should?
Vehicle is not equipped with a BOV.
It does seem like certain boost sleds experience this where the rpm will hang for a second before coming back down all the way to idle resulting in a run on type scenario when letting off. Could be throttle blades/spring unable to completely close right away when boost is applied and it takes a second for the spool down to allow it to happen.
Also could for sure be clutching not backshifting fast at all resulting it to hang in gear for a moment.
I personally have not experience it in over 1k miles on my boost. But also running non stock clutch calibration.
Just got back from a trip and buddies new 23 Boost did the same thing (300 miles on it). Took it for a rip and had a few seconds of go after the throttle was off. Looked for the cable adjustment under the hood and noticed the cable was ziptied tight and had a kink in it. Figured the cable was slow in retracting through that spot. Lots of codes on his 7S dash with only 6 days on the sled.
How does it dump excess pressure after throttle is chopped?
Bleeds back through the compressor wheel.
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Happens on my 9R as well. Hate it in low snow
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Sent from my iPhone using Tapatalk
Thata that fancy shuttering noise. That's the compressor surging as air goes the wrong way. Also why the intake vents shake when you chop the throttle under load.
Otherwise comments about throttle cable drag is worth noting. I had a cable replaced on my 22 as it was kinked and weird where attached to airbox. Never caused any issues besides heavy flipper pull but could easily caused a delayed throttle release.
Bikeman Tuning fixes this! if it the tuning part of the issue otherwise sometimes snow can get wedged in throttle also.
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Both my turbo and 9R did this occasionally until I installed the adjustment screw back into the secondary and tighten it up just enough to keep the secondary from causing the belt to be fiddle string tight when clutches returned to idle. Had no more problems with the run on condition again. There are more reports on this in snow west forms
I feel the need to chime in. And not saying this is the issue with your sleds running on. But, i have an old 850, the only sled i have owned with the throttle cable zip tied to the air box. Throttle stuck once two years ago and once last year, until multiple times this year finally causing me to replace the front bumper and a lower A-arm. I finally cut the zip tie and found the black outer coating deteriorated and pieces of it getting into the cable between the spiral metal casing. This was not visible through inspection without cutting the zip tie. I just thought it was a frozen throttle the first couple times.
CUT THE ZIP TIE HOLDING YOUR THROTTLE CABLE TO THE AIR BOX
CUT THE ZIP TIE HOLDING YOUR THROTTLE CABLE TO THE AIR BOX
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Mine stopped doing this as soon as I did the fuel sensor wiring fix.
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Can you please explain more?
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Sure. There's a known issue on the Boost with the connectors on the wiring to the fuel sensor. The connectors "break" but appear healthy and cause issues with high idle, erratic rpm, hanging idle, low fuel pressure code, fouled plugs. Mine suddenly developed all of these symptoms at the 5 hour mark, including "cruise control" where after chopping the throttle the rpm would hang up and the sled would continue on it's own (without any ice or snow in the throttle block). Made me terrified to load it onto my sled deck when it happened after getting off the mountain. Wife and I were on a trip at the time. The local dealer knew the fix and set me up that same day. Everything was good after that. A lot of dealers are providing the fix now. Hopefully it becomes a recall.
This guy has a decent video showing how he fixed it.
