Need Help with 4.3lx Rpm readings too high

[alex3012red]

rebuilt engine, put back on the boat and sounds perfect, But took it out on the water and the rpms seem to read a lot higher than they really are, and when it reads 5000 rpm, it start to cut off, and the engine is not close to 5k its more like 3k rpm.I could only cruise 4800 rpm(It's more like 3K) I don't know if i got a wire in the wrong place. I don't have a wiring diagram. By the way the it's a 1992 4.3 LX thunderbolt ingnition. anybody could send me one it would be appreciated.I was also thinking the thunderbolt box could be messed up but how would I know.

 

[180shabah]

Re: Need Help with 4.3lx Rpm readings too high

Start with the tach - there is a selector on the back of it. Cycle it a couple times, then set it for your 6cyl.