what rpm, i dont know, dont have a tach. it happens in second gear. i only have a 2 speed torque drive transmission. but i did remove the driveshaft and added grease to the joints, and turned it back around. also my timing was off by a bit. i did get it to 6* and tweeked the carb. also, i did check all the the nuts and bolts on the front end, i mean everything. and last i did switch the front tires. now i will see what she does when i take it to work. it is my daily driver, i just need her running safely. o yeah, i also checked the rear end tires and all, it seems good and tight, except the bushings. starting to crack. but the vibration is in the front, so i will look into that later. im just hope its a tire, and thats it. thanks again. let you know whats the deal.