Hey, i just bought a 07 redcat MPX-150 with the GY6 engine, i had to buy a new gearbox for it off the bat, and just put the new one on last night, now there are 2 problems i'm having that i'm not sure about so if anyone could help me on this i would be grateful. 1. it's idling high and i think it may be because of the choke because i gotta mess with the choke a little till i get it to go down (its a cable choke) is there anyway to adjust it maybe? or is it with the carb? and 2. when i start it and put the gear in drive from neutral it kicks in really hard and jumps forward, now like i said this gearbox is brand new, does it need more fluid maybe? when i look in the little window on the front you can tell there is some fluid in there but the window is clear so i'm guessing the fluid level is below that window, i'm new to these Chinese atvs so i don't know much at this point about it. thanks for any help anyone can give me

 

It sounds like you need to back off the idle screw on the throttle. It is a small philips head screw where the throttle cable hooks to the carb. On my gy6 engines I have to adjust this based on how the engine is acting. You may need to tighten it down a bit to hold the idle while the engine warms up, and back it down once the engine is warm. Your hard shift is a side effect of the high idle rpm. Look up any video on you tube regarding a gy6 cvt belt. You will see that the assembly is always in motion. And the vehicle will stay in nuetral until the rear pulley spins at a high enough rpm to engage the centrifigal clutch and put power through to the final drive. If your engine idle speed is too fast, the clutch never fully dis-engages, so you are never truly in nuetral. With this being the case, when you shift, you are throwing the gear box into gear and will recieve a hard shift and or gear grinding. Once you have the idle set correctly

 

Once you have the idle set correctly, you should be able to shift smoothly into drive or reverse. On my 150, when I shift, I have to wiggle the quad a small amount to move the gear box a little to allow the gears to mesh properly, before applying throttle. If I forget the little wiggle to mesh the gears, I will either hear the gears grind and hard shift, or the shifter will pop back to nuetral.