I have a mercruiser 4.3 LH, Thunderbolt V, Weber carb, Alpha 1.<br /><br />Out on the boat the other day, I looked at he tach while cruising, and saw that it was reading 6000 rpm !!! I don't believe it...the rev limiter shouldn't let this happen and the engine didn't sound any different. Back in neutral, the indicated rpms were also higher, even though it didn't seen to be idling faster.<br /><br />This must be a false indication. Could the guage, itself, be bad? I have a volt meter, but not a tach. Does anybody know the correct relationship between the signal to the guage and the guage readout? ( for example: 6 volts = 3000rpm) What else could be the problem? Again, I'm pretty sure it is not running as fast as indicated. Thanks.
