I have a 2.6KB on 18lbs. 8rib set up. 15%OD balancer, 3inch blower pulley, Thumper RRR HD tensioner, Meziere ELE water pump with idler pulley for the KB, still have AC and PS. My problem is this..... The power from the engine is pulling up on the tensioner of course and when I let off to shift it allows the tensioner to slap the tensioner idler into the AC pulley therefore sending the belt to hell and back! LOL It actually left a groove in the 76mm idler pulley. I traded out for a 70mm idler pulley but it fucked up another belt but didnt seem to hit as hard on the idler pulley. I feel as if a smaller idler like the 63mm that comes for the GT500 would solve it. Has anyone else had this problem? Any suggestion? It only does this in 1 and 2nd gear. I assume 3rd and 4th rev slower and it has time to catch up. I noticed the factory tensioner has a stop on the down stroke but the Thump piece does not. Anyway thanks for any help as I searched but found no one with this issue.


