A few visual items to check:
Below the operators seat, make certain both of the By-Pass(Tow) levers(A) & (B) are "fully" in the rearward position.
Drawing below:
Check that both bypass levers on each transmission is in the "return" position. (drawing below)
Inspect the return spring on each lever.
Remove any debris that may be hindering their operation.
Check the condition of both transmission sheaves. remove any debris.
Drawing below:
Check condition of drive belt(1) and sheave(6).
Check that belt tension lever is operating properly.
Check condition of return spring.
Below the operators seat, make certain both of the By-Pass(Tow) levers(A) & (B) are "fully" in the rearward position.
Drawing below:
Check that both bypass levers on each transmission is in the "return" position. (drawing below)
Inspect the return spring on each lever.
Remove any debris that may be hindering their operation.
Check the condition of both transmission sheaves. remove any debris.
Drawing below:
Check condition of drive belt(1) and sheave(6).
Check that belt tension lever is operating properly.
Check condition of return spring.