I bought a used engine for my wives 99 zx-9r and I can't say for sure what year the engine is but the parts dealer said it would fit 98-01. Everything fits except the cam boss sensor. On the 99 the cylinder head is drilled out for the sensor location, on the engine that I'm trying to install the hole is filled from the factory. Can the 99 model run without the cam sensor installed. The igniter for the 99 and the 00 model are the same the only difference that I can find is that Kawasaki elminated the cam boss sensor. If there is anyone out there that has every run into this I would greatly appreciate your input.