I made the adjustments per the repair manual (jack mower up, loosen lever bolts, etc) and monitored tire pressure, but I have to keep correcting the levers while in motion to keep it from veering off and when I do that, it messes up the stripes. I know ZTRs are not that good on grades but it's horrible on even the slightest grade and it's really getting on my nerves!! Would like to be able to go in a straight line with the two levers in the same position but the mower will slightly turn wherever the lower part of the grade is as if the one wheel is almost in neutral. Is there any way I can fix this? Thanks.