2021 Mountain cat 165 800 - BOG at WOT

[bcpowder]

I’m on my 3rd Ctec2 800. Had the 18, 19, and now the 21. All have been awesome.

I run bone stock with a speedwerx muffler as the only modification. I’ve had the same Can on the last 2 sleds without issues.

My 21 has been having real bog issues at WOT. Sounds a lot like when all your air intakes get plugged and it won’t rev up. Only thing is it happens often when the air vents are completely clean. It also will happen mid climb with the skis in the air fully pinned. Off the throttle and back on usually clears it. so it doesn’t appear to be an exhaust clogging issue. Clutches seem to be running smooth as well.

I assumed it was just a break in rich fuel issue, however I’m now at 12 hours and it’s still happening. I also checked the power valve cables and are both bang on 36.5mm

has anyone else experienced this or found a solution?

 

[kiliki]

un plug the throttle safety switch for a ride, the plug is on the coolant bottle side and I think on the 2020 it was black a yellow wires. you can peek at it wires at the throttle block to make sure.

 

[bcpowder]

I’ll give that a try. I should also mention it runs fine 95% of the time. But that 5% really gets you in bind when not expecting it.

 

[kgra]

I don’t remember how to set the gauge up but you can set it to see temps in numeric instead of just a bar. Monitor egt for a wierd reading compared to when it is good. Temp sensors can cause these issues and fail new or old. My first guess would have been the power valve adjustment but you tried that.

 

[Old & slow]

I’m on my 3rd Ctec2 800. Had the 18, 19, and now the 21. All have been awesome.

I run bone stock with a speedwerx muffler as the only modification. I’ve had the same Can on the last 2 sleds without issues.

My 21 has been having real bog issues at WOT. Sounds a lot like when all your air intakes get plugged and it won’t rev up. Only thing is it happens often when the air vents are completely clean. It also will happen mid climb with the skis in the air fully pinned. Off the throttle and back on usually clears it. so it doesn’t appear to be an exhaust clogging issue. Clutches seem to be running smooth as well.

I assumed it was just a break in rich fuel issue, however I’m now at 12 hours and it’s still happening. I also checked the power valve cables and are both bang on 36.5mm

has anyone else experienced this or found a solution?

I saw that on a 18 and it turned out to be the intake was ingesting snow.

 

[bgraff1]

wont be the TSS, that would cause the sled to cut completly out like you hit the kill switch, not make it bog

 

[bcpowder]

I don’t remember how to set the gauge up but you can set it to see temps in numeric instead of just a bar. Monitor egt for a wierd reading compared to when it is good. Temp sensors can cause these issues and fail new or old. My first guess would have been the power valve adjustment but you tried that.

Hmm, good comment I will try that next. It’s definitely not ingesting snow. Confirmed air box is sealed and intake is dry when I take the hood off. I’ve blown out all the connectors, reinstalled stock muffler, added water evaporator to the tank, unplugged the tss and the kill switch. The clutches seem to be moving freely. Primary spring looks fine and the spark is strong. Haven’t checked the fuel filters yet maybe I’ll pull that out today and have a look.

 

[IowaM1000]

Don’t know if you’ve tried this but I’ve been chasing top end issues on 2020. Ran great other then on top like your describing but mine was doing it the majority of the time. Ended up needing to add primary weight because the engine was trying to over rev but the computer detuned it before it had a chance to actually over rev. Which made it sound like a bog at WOT. Mine has a 900 in it but I’m sure it would do the same thing stock. Good luck!

 

[deanross]

I’m not any help, but did Arctic Cat finally address the air intake gap? Seems like everyone was having to silicone around the air intake the past few years.

 

[uofm]

I have a new Mountain Max doing the same thing. It feels like the clutch did not back shift all the way like it is in high gear. Let off the throttle and nail it again and 99% of the time it comes out of it. It can be very annoying at particular times. Dealer said the computer showed no sign of bogging.

 

[boondocker97]

Have you guys checked the helix and rollers in the secondary? Chewy22 on here had a OEM helix binding on the rollers like the slot wasn't machined wide enough. If running the stock helix is it trying to pull too steep of an angle for the elevation and snow conditions?

 

[Chewy22]

Boondocker97 is right. Pull the secondary apart and make sure the rollers aren’t binding. I know a couple others that had the same issue with the stock helix.

What your are describing is exactly how mine acted.

 

[Frostbite]

My 2020 hardcore did the same thing. It pulls hard but in the deep when I pin the throttle it bogs. It could be I need to add more weight to the primary or the secondary issue described above. I have MDS weights with 74 grams each and my issue was just over 6,000 feet.