Hello I just bought a 2001 Wellcraft Excalibur 23 with a Volvo 7.4GI, SX drive 1.43 ratio, it has a 19 pitch 3 blade prop on it. Took it out and this is what I saw, at WOT tach showed 3300 rpm trimmed out, but my GPS speed was 53.4 mph. One time after restarting the engine, I noticed the tach reading differently, I had been cruising at 2200 rpm Speed about 29-30 mph, now the tach showed 2800 rpm with same speed, so I go to WOT tach shows 4300 rpm, speed 53 mph.
I am guessing this is a tach issue but before I buy a new tach, is there a trouble shooting guide to use?
Thanks
I am guessing this is a tach issue but before I buy a new tach, is there a trouble shooting guide to use?
Thanks