Hi I have a yz80 with a problem that iv tyred every thing to fix just dnt seem work right when she starts rev in nutral it revs and sound fine soon as you put it in gear revs drop and it's really sluggish to pull of put on full and just starts to bog for a sec then it comes to life and front ends up can eny o e tell me y it's like that when you pull off if you keep revs up high it's like a rocket but if you dnt it's really sluggish