Nytro Low RPM Stumble

[yelliscreamy1979]

Hello all, I'm currently knee deep in the search for a cure to my Nytro woes. My Nytro, Which I have owned since new and now has just under 8000 miles has, in the last couple rides has developed a low rpm miss. The engine stumbles at low rpm (5500) and you can hear the miss in the exhaust. I first noticed it when I was playing some powder and when banked to the right, the engine bogged almost like a two stroke when it fouls a plug. Once I levelled the sled the engine recovered. I also noticed it at slow steady throttle on bumpy trails. My first attempt at solving was taking a look at the the wiring harness rub issues that others have posted. I found a few common rub points but no indication of bar wire. After making the repairs to the harness, I started the sled and the hesitation remains.
Gents, I'm not an electrical savy guy out there so I'm not sure what to test. My understanding is that the sled has a diagnostic mode but not sure how to get it into that mode, or even what to look for once in that mode.
I know I have a weak battery at the moment as well, but I doubt that is contributing.

Some additions to the sled include hand and thumb warmer booster kit as well as Hindles exhaust and air intake modes with PC V fuel controller.

Any help or possible recommendations would be super appreciated to get my this beast back on snow.

One more thing...it still runs strong up top...just seems to stumble down low.

 

[yelliscreamy1979]

Hello all, I'm currently knee deep in the search for a cure to my Nytro woes. My Nytro, Which I have owned since new and now has just under 8000 miles has, in the last couple rides has developed a low rpm miss. The engine stumbles at low rpm (5500) and you can hear the miss in the exhaust. I first noticed it when I was playing some powder and when banked to the right, the engine bogged almost like a two stroke when it fouls a plug. Once I levelled the sled the engine recovered. I also noticed it at slow steady throttle on bumpy trails. My first attempt at solving was taking a look at the the wiring harness rub issues that others have posted. I found a few common rub points but no indication of bar wire. After making the repairs to the harness, I started the sled and the hesitation remains.
Gents, I'm not an electrical savy guy out there so I'm not sure what to test. My understanding is that the sled has a diagnostic mode but not sure how to get it into that mode, or even what to look for once in that mode.
I know I have a weak battery at the moment as well, but I doubt that is contributing.

Some additions to the sled include hand and thumb warmer booster kit as well as Hindles exhaust and air intake modes with PC V fuel controller.

Any help or possible recommendations would be super appreciated to get my this beast back on snow.

One more thing...it still runs strong up top...just seems to stumble down low.

I should also note that I Changed the plugs as well. Old ones looked great. No wetness and all had a light brown tinge.
I also have run a bottle of gas line antifreeze and multiple tanks of fuel since the onset,

 

[shadow44]

The addition of a full exhaust will bring out the "stumble". Some sleds do it more than others, I've never really noticed it enough to let it bother me. I hear it on occasion, more so when I let right off the throttle and get back into it hard. When I'm smoother with the throttle I don't hear it. It's nothing to be concerned about imo.

 

[devilnabludress]

With my Hindle exhaust, the "stumble" sound is more noticeable than stock. They all do it, some more than others, depending on how "burnt out" the stock muffler is, and once the aftermarket is on, way more noticeable. 5 Nytros in our group (Hindle, MBRP, Barker and 2 stockers) and they all do it.

 

[radianguy]

Link to diagnostics mode...

http://www.ty4stroke.com/threads/fault-codes-relay-fuse-location-wire-diagram-diagnostics.83992/