Nitro 150 xr6 23 tempest rpms high

[bassman_n]

I have a 18'2 " nitro with a 7" setback, 150 xr6 with a 23 tempest. I am running the tempest 23 at 5800-5850 rpms at 58 mph with 2 guys and a tournament load. Mercury calls for Max RPM of 5000-5600 RPM. The motor is running above the pad with the cavitation plate about 2-3" above the surface of the water at WOT. I have had the motor as high as two holes higher on the jack plate but it scared me. The boat ran great (cornering suffered) but the cavitation plate was 5" above the surface at WOT and even with the top three holes epoxied closed I worried about the water pressure even though the gauge seemed fine. Max rpm was the same as it is now 5800-5850. The motor is not moving again (the X factor will not change). I have trim extenders on order due to the negative trim angle built in to the setback. Boat test.com said they ran the boat at 61mph with a 25 Tempest. I am looking for a better prop. Tempest 24-25, Turbo Lightning?

Tempest 23
5800-5850 rpm
58mph(GPS) 2 guys tournament load
Full trim, rooster tail about the hight of the motor hood(no higher) prop shaft level with waters surface.

 

[Senderofan]

Re: Nitro 150 xr6 23 tempest rpms high

I can't give you any direct advice on a prop. I do, however, have the same motor on my boat. I did a querry on the site "Scream and Fly"...a site for mercury motor tuning and performance tweaks. The guys there were unanimous in recommending running at the top of the rpm range...and / or up to about 5800 rpm. It seems the 2.5 liter V6 likes to rev...I have to agree since I dropped to a 19 pitch prop and max out @ 5600-5700 rpm.... it seems to be an altogether different driving experience. But I'm pushing a big aluminum fish and ski.

If the experts can't help you here...maybe post your question on scream and fly: http://forums.screamandfly.com/modules/Jig/index.php I'm not promoting another site....but they could tell you what rpm would be best to run with your set up and motor.

Good Luck,

Wayne

 

[LubeDude]

Re: Nitro 150 xr6 23 tempest rpms high

Don't claim to be an expert, but I have set up a bunch or Bass boats over the years. With the boat and power mentioned, I think that you are about where you should be. That engine likes the high end of the RPM range! Your holeshot will suffer if you go up in pitch!

 

[bassman_n]

Re: Nitro 150 xr6 23 tempest rpms high

My buddy runs a Tempest 23 at 5500 rpms at 60mph, I'm running 59mph at 58-5900rpms. I'm looking to beat him. I don't care much for hole shot I run deep lakes with a long way to go.

 

[bassman_n]

Re: Nitro 150 xr6 23 tempest rpms high

It appears that the new power head is now up to 6100 rpms.