Seadoo 787 (800) and 947 (951) engines, utilize a counterbalance shaft to reduce the vibration and harmonics for smooth operation and engine longevity. When performing an engine overhaul, it is important that this component is also serviced! The shaft has several bearings and a few seals that should be replaced to ensure you have a reliable powertrain.

The shaft is geared at a 1:1 ratio with the crank so if the engine has higher hours, it is good practice to proactively replace them even if they seem smooth. Another failure mode is water finding its way into the counterbalance shaft area through the oiling holes in the lower crankcase from the engine ingesting water due to a failed cooling line, hull failure, flipping the ski, or simply rolling it the wrong direction. This water will cause rusting and lack of lubrication which will lead to a catastrophic failure and even a rupture of the crankcase.

In order for us to rebuild your counterbalance shaft, please fill out our Work Order Form and follow the directions provided.