Gardingh,
What you described for checking plug is right on. You sound like you know the stuff. You have to remove the front fender and some plastic coverings/air box to get to the carb on your BF650i - the carbs are well hidden and there is no other way. It takes me at least 30 minutes just get to the carbs. While you are experimenting with jetting, do not put back the fender or any other stuff that you don't need to run the quad.

While the fender is removed, you may check/adjust the valve clearances and set them to the looser (higher number) side of the spec so that they will last longer. You don't have to check anything else if you don't have any problems now - if it ain't broken, don't fix it.

 

Hyashi - Thanks for the info, I don't plant on touching it but I will check the plugs just to see where it is at. It runs fine as it is, runs smooth all the way through the throttle range and once it is warm it will idle nice and smooth as well.

rtboy - That doesn't surprise me at all that it got a little slobbery with 8000ft of altitude change. I can't even get that high around here unless it's on a sled. We have some trails that run around 7000ft but if mine is jetted properly here, 8000ft of altitude change will put me at 10000ft. I've been up that high on my sled and you don't last long up there without getting a little tired yourself. The 4x4 isn't a big deal, I got stuck the other day in 2wd in the snow. Fell of the trail and couldn't climb back on. I managed to break a trail back and forth enough to give me a short distance to run so it would shift into 4wd smoothly. I find it will shift equally well in reverse too which I found out after spinning out on a steep hill. I find my machine will switch smoothly within a couple rotations of the tires provided they are both turning equally. I don't know about the 5mph thing but mine will switch almost right away if you hit it at a dead stop. I haven't tried it when stuck and can't move but I have read that it will go but it's not pretty so I chose to avoid doing that. I have a good size winch, ****** block and a tree strap so if need be I'll pull myself out of the hole before I smash up the drive train.