Ijust picked up a 1976 tnt 340, the old belt was very thin width wise but at least the machine moved. The new belt makes the machine creep foward and die, i know you can adjust the lenth of the belt by the chaincase and the motor mounts but this did nothing, it seems the secondary is to tight for the new belt, can someone please tell me how to make the adjustments. thanks.. and yes the new belt is the proper #..

Sounds more like the secondary is to loose and dropping to the bottom to fast and making it die, adjust the spring tension.

thanks i will try that, but can the tension be adjusted ?