93 Ranger 362 spinning tempest plus 26p to fast ?

[BobDeaton]

My Ranger 362 , 150 mercury 2.4 spins a 26p tempest plus over 6000 rpm according to my tach. Boat is going less than 50 (gps)at redline and I have to keep rpms down to avoid going over. This is a new boat to me so still getting used to it.
I am wondering if the tach is correct. Could it be faulty ? I think I will have to go to a higher pitch prop to drop rpm's if the tach is correct. Anybody have experience with a 90's ranger and a merc 150 ? any thoughts are welcome.

[1ranger487vs]

Sir you have a problem. No way a 150 will turn a 26 that fast. Tach is off or a bad prop hub. How is the hole shot.

[BobDeaton]

hole shot is good. Pops right up on plan

[mactlman]

Badly worn out prop?

[1ranger487vs]

Sure it’s a 26. Based on those numbers at 10%. Slip it’s like a 20

[BroWhoop]

Tach

[BobDeaton]

Thanks to all for reply ! so I bought a cheap digital tach that triggers off spark plug wire and it shows I am not even close to redline and boat tach is pegged at max. I thought the boat did not sound maxed out . Next is replacing the old boat tach.

[mactlman]

Sometimes, if you can reach the back of the tack, there’s a Row of dip switches that you can move back-and-forth several times, just gotta put them back where they were originally, and that’ll get rid of the corrosion and resistance and make the tach work correctly again

[1ranger487vs]

Could be something with your rectifier if I remember right

[twitch]

check the switches on the back of the tach first and like stated above make sure you put them back where they were when done,could just be they are dirty and bad connection. In my understanding usually a rectifier will just not make a tach work ,don't think it will make it work wrong but not 100% sure on that you should probably be spinning a 24" prop to get more rpms and speed