A friend of mine bought a PCM# RK107025A  conversion kit from Nautique Parts. He asked if I could install it for him . It seemed pretty straight forward so I said yes . I thought the kit was made for this conversion but it is more like a bunch of cobbled up parts that are close but not quite a perfect fit to his engine. The directions are a joke hand written and very generic. He also supplied me with a copy of a wiring diagram for this kit off the forum . Using both and the knowledge I have from 40 years of working on 351 PCM engines I got it done . The boat runs great but I have a couple quirks . First the volt gauge reads low around 12 volts but 14.2 at the battery. Second the tach reads low about 4-500 RPMS it increases with the throttle but is off. The owner thought he has a ground issue in the dash that causes the volts to read low but the tach was reading fine before the conversion . Has anyone installed this kit and had similar issues? Any ideas where to start the gray wire is securely attached to the - side of the coil  ,

I suggest while running, first check all hots from the buss and keyswitch out to harness to iginition and choke, against battery ground and find where the drop is, and address.

Mike,

An 8 cylinder engine with the tach set on 4 cylinders will read double the actual RPM.