The tachometer on my First 38 has to "warm up" for a few minutes before it reads the correct value - it seems to be max out at 1500 at first. The engine access is pretty bad without removing the cockpit sole, so I haven't even found the sender yet. Can anyone tell me where the sender might be on the "new version" of the 4-108, how it works, why it might be sluggish when cold, or other suggestions? I'm pretty sure the gauge is electrical (not mechanical), although I haven't looked very hard, as the boat is an eight hour drive from home.