Thoughts

[Rocco73]

I'm running a 2001 triton tr-21 with a 2001 Yamaha ox66 3.1L 225. Prop to pad is 3 1/2". Prop is a 23-M. At 5200 ft above sea level. 6" manual high jacker.

With 450lb of people, 3/4 tank of gas, both live wells 1/2 full ( I forgot to shut the vale). I'm getting 57gps at 5800 rpms. I just purchased this boat and only have had it out afew time. I was hoping to hit mid 60s. Any advice. Or thoughts.

[Rip Bass]

That is very slow for that rig but I don't know how much effect a mile of altitude will have either. My opinion is try a Tempest+ 23 and raise the JP as high as you can without losing water pressure. Lots of Tritons run well at 2-2.5" under the pad.

[mdtritn21]

How much set back do you have? Your showing a lot of prop slip but that could be from the load you where carrying. Try borrowing a 24" tempest prop to run since that motor has 1:81 gears and see if it will get out of the hole. You can raise it up 1/4" at a time until it gains rpm's but not speed, loses bow lift or water pressure. That motor only needs 11 lbs WP.

[Rocco73]

How much set back do you have? Your showing a lot of prop slip but that could be from the load you where carrying. Try borrowing a 24" tempest prop to run since that motor has 1:81 gears and see if it will get out of the hole. You can raise it up 1/4" at a time until it gains rpm's but not speed, loses bow lift or water pressure. That motor only needs 11 lbs WP.

6" manual high jacker. And thanks for the advice every one

[mdtritn21]

You really need 8" of set back on a Tr21.

[Rocco73]

You really need 8" of set back on a Tr21.

my 6" high jacker will only get my motor to 2 1/2 below pad. Is this normal?

[mdtritn21]

No you probably need to raise the motor one hole on the plate.

[Rocco73]

Thanks for the help

[Rocco73]

At 2 1/2 below pad and with 60lb more weight in the boat I hit 58.3 at 5800rpm. I do have a 4ft roaster tale now. I guess my next step is to move the motor up on the jack plate to the last set of holes and reset it to 2 1/4.

[grout-scout]

I'd have your motor looked at, it sounds sick.

Unless the altitude has that much affect.

[rat0502]

Are you getting wide open throttle for sure?

[Rocco73]

Yea I've check. And the motor is good all the celinders test out at 127 / 129 the power head is new only 30 or so hours on it. I think that at 5200ft it's what I'm gonna get. I'm gona try a 24 if I can find one around here to try. And get my 23 work.

[grout-scout]

Just seems so odd that I read about all these Tritons with blistering speed and yours sounds like a dog. Have you talked to a shop in the area to see if the altitude could be the problem?

[mdtritn21]

So you added weight raised the motor and gained speed but now you have a tail? You need to have the prop repaired to get rid of some slip. Don't raise it any more before getting the prop repaired because it will just throw a higher tail. grout-scout 5200' elevation cuts his hp down so he's running less than 200 hp now.

[pmgoffjr]

1,000 ft of altitude is about 150 rpms. He's at about all it'll do right now. Tweak your prop, get some plate extensions, and go fishing, you're done.

[grout-scout]

So you added weight raised the motor and gained speed but now you have a tail? You need to have the prop repaired to get rid of some slip. Don't raise it any more before getting the prop repaired because it will just throw a higher tail. grout-scout 5200' elevation cuts his hp down so he's running less than 200 hp now.

Wow, that is amazing. I never would have thought it would have been that much power loss.

[rat0502]

Wow, that is amazing. I never would have thought it would have been that much power loss.

Me either. Amazing what altitude will do.

[mdtritn21]

http://wahiduddin.net/calc/calc_hp_dp.htm Engine tuning calculator

[Invader186S]

I'm also at about 5000 ft. With my setup, I should be in the mid 80s close to sea level but here I'm in the low to mid 70s so I'm down 10-15 mph. Besides being down on horsepower, I have a theory that I loose bow lift due to the less dense air....it's just a theory.

I've improve my speed by using a lot more setback, lots of trim, higher engine height and larger diameter props. A TR-21 with a 225 at 5200 ft, 57 mph is probably not that far off. Consider, using a Tempest or T1 prop, more setback, possibly wedges or trim extenders all may help.

[Babe Winkleworm]

Rocco that's about all you can expect out of your rig here. I can only get 62-63 out of mine around here.
PS nice new rig btw.