Questions about Tach and Trim on a 21' Regal

[captmorgan23]

I have a 1999 REGAL 2100 LSR and am still learning about the boat. It has the Mercruiser 5.0 liter v8 EFI and when I am cruising at around 50 miles an hour I trim it up and the boat starts to move faster. My RPM's are right about 5000 maybe a little higher. The Tach has red marks starting at about 4200, and the boat hits this at about 45. It doesn't seem to be rapped out and has more to give, and I am not even at WOT. Where should these run? I don't want to blow my engine, but it doesn't seem like the motor is being overworked. Is the tach wrong? My prop has a 20 pitch..... but like I said I am still learning and would love some input on the optimal cruising speed and where I should be as far as trim and top speed as well as what my tach should read.

Thanks everybody in advance

 

[captmorgan23]

Re: Questions about Tach and Trim on a 21' Regal

I just noticed I posted this wrong........so I apologize and hope the appropriate authorities will move this to the proper topic.

MP

 

[Chris1956]

Re: Questions about Tach and Trim on a 21' Regal

5K RPM is a bit high for a V8. You probably want to increase to a 22" pitch prop. You probably want WOT RPM to be in the 4600RPM range.

Is your speed accurate? it sounds a bit higher than I would expect in that setup.