Yamaha GP1800 as it comes out of the box clocks 68-68.5mph at 7400rpm according to R&Ds testing data. The American company has been consistently working on developing a kit for close course use according to the new Stock Class rules of IJSBA. The kit includes the following: Intake grate aquavein, ride plate, pump seal kit, Pro series filter kit, reprogrammed ECU, Pro Pitch impeller at custom spec, Pro series Axis adjustable sponsons, According to the extensively testing schedule of Bill Chapin the R&D Pro Stock tuned GP1800 clocks 84-85mph top speed consistently at 8600rpm. The R&D Pro Stock kit for the GP1800 will be also available from Kommander Industries for the customers that willing to buy a Pro Stock tuned-up ready to go ski.
