Help! Motor seems to be getting choked out

[tapex_07]

Ok so I'm here in Cooke City and the snow is practically epic!! Here is my problem, on the trail, shallow off trail, or nose out of the snow the motor runs mint. 9200 rpm in town and down to 8600 at ride elevation. Once I get into the deep (3'+, over windshield) it seems like the motor gets choked out like and drops to 5-6k rpm and runs like poop!!!! Only thing done to the sled engine wise is; tunnel dump, cr10ek plugs, and stock CO's. It's the same as last year and it ran perfect out here.

Any suggestions or help would be great!! Thanks

 

[sonds]

Sounds like your ingesting snow, have you taken a good look around the air box? Are you getting snow in other areas around the engine compartment? Did you screen the inlets on the hood and cowling?

 

[tapex_07]

It sounds like ingestion to me too. But I just can't believe it being 100% stock up there. Are many ppl having problems with this?? The open vents next to the headlight are open and uncovered. If I close them off, will it choke off the air supply?
Oh ya I forgot, NO codes thrown either.

 

[HYFLYR]

Yes, you can block those vents and wont hurt anything. Dropping to 5-6k is awfully low, does it sound like a bog through the motor as if running fat or just cant pull rpm through clutching? Have you checked to see where the belt is riding in the clutches by chance? Is it possible you exhaust is plugging and causing it to stumble. I have see this on some setups but not all under tunnels. Good luck hope you get it going.

 

[Nikolai]

If nothing else has changed I'd say it's the exhaust. Can you post a pic of your under tunnel setup?

 

[tapex_07]

I think ill try to block the vents off first. I checked the plugs right after it does it, if anything they look lean. I thought the exhaust was getting plugged too, but it still does it even going down hill with the tunnel area looking clean..
My tunnel dump takes a 180 and faces forward with the direction of the track. Thanks fellas!

 

[mtdream]

is it doing it more to one side or the other? is it when your just riding flat and pow is coming in? or is it while turning?

was your tunnel dump installed last time too?

 

[tapex_07]

MT- it did it in any position. Left, right, uphill, downhill, slow plowing. Yes tunnel dump was on last trip out, but never in this much deep POW just amazing snow! I'm heading home now, I'll update what I find when tear it apart this week.
Thanks

 

[HYFLYR]

Lean would give you lots of popping and farting so unless it was doing that it would leave me to believe it was a rich condition. Curious to know so please let us know when you figure it out.

 

[mtdream]

it also could be an O2 sensor reading to much air...but, most logical is something with the tunnel dump design...

I know of lots of them, and most have been just fine...if the exhaust is near the front, it clearly can get plugged up...most have it a ways back...

 

[Jabber]

It is most likely your exhaust. I had exactly the same problem with an RX1 when in DEEP powder. The problem was the glass pack exhaust pipe had collapsed on the inside. It only left an opening of about 1 inch. I replaced the glass pack and no problem since.