I have a 2021 Blast ZR 4000 with similar problems. Bogs down / sputters at trail speed. At higher speeds 55-60, when it sputters the sleds tries to stall out and drops about 25mph really fast. Have thrown the P1324 code on two trips. Sled is currently at the dealer who is working with Cat but they don't seem to have a solution. The season is too short for problems like this!Owner of a 2021 ZR8000 RR
First Weekend threw Code P1324 (Knock Sensor?) A phone call to the dealer = dealer said bad gas
Second Weekend stumble, bog, hitting rev limiter when I would stab it after cruising with the family for a few miles? very annoying
Third weekend the same as the second- Not loving this sled
Fourth weekend riding with buddies at a much faster pace- Ran hot and constantly was looking at a blinking light looking for deeper snow off of hard packed trails on top of the Stumble, bog or rev limiter? Riding with a 2020 ZR8000 that ran 12-15 degrees cooler all day and he burned less fuel.
Starting to hate this sled
850 Miles so far and going to drop it off at the dealer today-
Anybody else having these issues? I have heard of the bog stumble but it feels more serious to me like the ECU is holding it back at times. Other times it runs great but never for a full ride.
On the bright side, the cooling system on the Blast seems to be very good. No issues