Did some work with this and tried the variable pot with the 50k 1/4 watt resistor and 50k trim pot. But its a pain to keep opening for a adjustment, so with a tach a 87K resistor was 6960rpm, 80K resistor limits to 7200 rpm, a 75.4 K ohm limits at 7440 rpm. Your not going to find the exact size resistor at your local radio shack but what they do have is a assortment pack and you can combine two resistors in series to get your total resistance. Measure with a ohm meter as the color code can be off. A 100K ohm resistor at 5% tolerance can be plus or minus 5K ohms. TIP: when your digging the silicone out under the board be careful for two reasons, 1, the factory mixed in silica with the RTV (potting compound) these are white small rock like chunks and requires finesse to remove. 2, when your removing the 100K resistor on the left side connection there is also a capacitor leg right next to where your digging out the 100K. If you cut that don't freak it just needs to be soldered back to the new resistor and the board. You can also install a three position switch where one side is 100K (stock) and the other side 75K (Mod) (just in case you let a rookie drive your ski). With this mod and a full ported (cylinders and cases), Factory B pipe, ADA head (200 psi), Solas jet with 85mm exit nozzle, and dual 38's. It does not hit the limit in the water. It is set at 7440 rpm. It will hit it out of the water, jumping or such.
