I have a 1993 kawasaki mojave and I have had this problem for a while and now decided to fix it now. When riding in first gear the quad barely moves, but when you open the throttle all the way the power will kick in. I usually have to cruise around in 2nd gear because 1st gear has no power unless you're reving the engine to the max. I think it's a jetting issue but I would like some others opinions before I try anything. I'll put a video link so you can see


https://streamable.com/74m5zg

 

Which gear you are in shouldn't alter how the bike runs regarding carburation. It does sound to have a stutter at low revs, probably indicating a weak mixture on slow running jet, and that is usually dirt in the jet. If, once you have cleaned the jets and passageways in the carb out and got rid of that stutter, you are still finding a difference depending on which gear you are in, this often comes down to a clutch problem.

 

I have cleaned the carb and still have this issue. It's most likely the clutch, I bought it second hand and don't know it the previous owner ever changed it.