Tachometer goes up to about 2000RPM and doesn't go any further at full throttle 3.0L

[spunkyman]

So here's the deal. I replaced a broken TACH (Faria) on my friends 2002 Four Winns 170 w/3.0L Merc with a NEW Telefelx TACH. After wiring it up, I started the boat and it ran up to about 800-1000 RPM at idle. This was probably not entirely accurate as the boat was probably revving at 1200. Neither here nor there, when I got out on the water, it wouldn't go much over 2000, maybe 2500 RPM at full throttle. I had set the screw thingy on the back to 4cyl. but perhaps there's a different or better setting that would allow it to get up to 4500-4600 where it should be? I was doing about 40 mph so it should be up around 4500.

Has anyone had this problem or could I just have it switched to something either than where it's suppose to be (on the back)?

many thanks in advance

 

[dingdongs]

Re: Tachometer goes up to about 2000RPM and doesn't go any further at full throttle 3

turn it over and there may be a setting for the amount of cylinders which will change the output.