I've been following this issue and based on internet reports it looks like it occurs early on - 200-300 miles or so. The problem is tied to injectors, and affects 800cc ZR's and Riots, and 400cc Blasts. I haven't heard of any reports from Norseman or mountain sled owners. So, that alone would tell me that the issue is limited. It also seems like a lot of people reporting higher miles and no problems at all. So, I think it's safe to say that it's only a batch of injectors affected. I have not heard any acknowledgement from Cat on this and nobody knows exactly how wide spread it is. It's probably not as wide spread as we think, but I'm hoping to see more information from Cat by early summer so that a recall can be completed before new 2022 sleds start being delivered.
There's also a persistent complaint about fuel mapping. Some think this is tied to the problem, but I don't - I think they are two separate issues. The mapping issue seems to affect a much higher number of sleds (potentially, all 400/800 engines), with some riders more observant than others about whether their sled exhibits the behavior. I say this, because at first I didn't think I had it and now I do.
Some of the riders affected by the injector issue report a stutter in the 6000rpm range just prior to meltdown. Most of the people reporting a mapping issue say their "stutter" is in the 4800-5200 rpm range. I don't think they're the same. Most of the injector failures occur without any warning at all.
I've been watching my EGT and it looks like temps rise significantly between 5000-6000 rpm. I'm seeing 700-900 below 6000 rpm and 1100-1150 above that. So, I wonder if the "bad" injectors show themselves right at that speed.
The importance of getting communication from Cat on this is going to increase over the next few months. Sooner is absolutely better than later.