I tend to ride using a lot of thumb, I will preface this with that statement. Off the line, I tend to mash the throttle for a bit and ease off as I achieve the speed I am looking for. In trail conditions, I ride with a lot of thumb, decelerate or brake even, then more thumb. I do not often hold a nice, steady RPM. So the issue seems to be showing at a couple of points in the ride. When letting off the thumb after accelerating, the RPMs sometimes drop fast, not wind down as usual – like there is no power there. Back on the throttle sometimes it just dogs. The pitch of the engine gets all blappy sounding and no power. RPM’s generally stay at whatever they were as long as I have the thumb down. Another point in the ride is in normal acceleration, as it winds up the RPMs it will "cut out" and get that blappy sound, no power. Sometimes I can feather it and get them to come back and then accelerate, however most times I just have to let off, and then baby the machine back up to speed (if on long stretch of trail/road). Last evidence, I have a very steep incline and when I attempt to go up it in high, I get the "cut out" loss of power within a few feet. Then I switch to low and it walks right up the steep section. However I think it did make the noise and cut out one time when I did it, as I was holding a pretty steady RPM up the slope and the back wheels started to spin so it took longer to get up the slope, more steady RPM seems to be associated with this issue. Figuring at this point that the issue does not show in low because the machine is more direct drive and does not hold the RPM or slow advance of RPM. I can’t really study that one too much because the slipping wheels on this incline makes for messy drawers – if the machine lost power and momentum on this incline it would be an insurance claim (and maybe a helicopter ride) instead of a posting on our site here.
So my operating theory is carb issues. Something in the bowl that gets sucked up in there after high fuel demand, but intermittently. Thought it could be electrical, the way it is slightly intermittent, but I just (for some reason) don’t think it is. There is also the thought that a clutch might be going but when this happens I do not see or smell any burning clutch or belt.
It seems that I can get it to happen pretty often, but when I try to capture it on video it does not do it or the buffeting of the wind masks the engine noise – I will post a vid soon.
