My brother just bought a cheap 86 yamaha ytf200. he got it cheap because it would only go into gear some times.

Anyway he also said he broke the shifter segmet for the shifter. we replaced that today . the bike will not move at all if a person is sitting on it, but if you put the rear end up on a axle stand she will turn the wheels in all gears.

could it be the clutch? I may have over tightened the clutch springs

 

nice avitar! and welcome to the forum! might be a tight clutch, not releasing itself enough when backpressure from the wheels is applied.

 

Thanks about the avitar

yea i wasnt sure how much to tighten the springs. i think that them may be almost bottemed out . no fully tho

 

I got one of these quads check the four bolts that connect the drive shaft if there a little loose the quad will goin and out of gear like you said with weight added or removed or the quad being turned left to right or vice versa