High Altitude Jet Kit or different Prop

[Okratpack]

Hey guys, I purchased a 1994 Stratos 285 Pro XL DC (19ft) with a 1994 Johnson 150 Fast Strike on it (J150GLERA). The boat came from sea level and now I fish at around 4000 foot. It ran 58 at sea level and only runs 38 now. Tach does not work. Takes about 8 seconds to come out of the hole. Runs smooth but slow once it is plained out. Current Prop is a Renegade 13.5 x 25 4 blade stainless. Dealer here says go with 21 pitch. Others say to put a high altitude jet kit in the motor. I can't seem to find a kit like that. Does anyone know where I can purchase one and does anyone have an opinion on whether I should re-jet or re-prop? What prop? Thank you in advance for the help!

[ChampioNman]

Sure doesn't help to try and give advice on your set up if your tach isn't working. Are you running a weed ring currently? If so you may want to pull it off and see if you have any performance increase. A 21 may be the ticket I'd try the prop first before messing with orifices.

[Okratpack]

Thanks ChampioNMan! No weed ring. I think I will try the prop first - if I can find one. Looks like everyone sells 14 x 21P and not 13.5 x 21P.

[usblitzz]

I run at 4-5K in elevation you will want 22P or less for sure.

Where are you located?

[Okratpack]

Located in Montana. I fish anywhere from 3500 to 4000 ft.

[ChuckS]

I run at 4-5K in elevation you will want 22P or less for sure.

Where are you located?

This. I was stationed at Ft Irwin 1994-1997. Had a Nitro 190TF with a 175 Evinrude Intruder that would spin a 26 inch Raker at close to 6k RPMs.

First free weekend I pulled it up toBig Bear Lake. Elevation 6 thousand and change above sea level. And couldn’t figure out why it wouldn’t get in plane. Local Evinrude guy was very polite and didn’t make me feel like a total idiot while he explained why and sold me a 22 Inch Raker at a premium.

Almost went through the same thing with my truck. Moved to Ft Leavenworth, KS in 1997. Towing through Colorado and the old Chevy 5.7 litre TBI is crapping out. Come around a curve on I-70 and see the sign for Vale Colorado, elevation 8k feet. Motor wasn’t crapping out. Just starved for oxygen.


I think modern automobile motors automatically adjust. Not sure about boat motors.

[joebone1]

we lose 20% or more on our snowmobiles when we go to wyoming between 8-10k feet. EFI adjusts but without the air density, you lose. We also have to change our clutching for the altitude and power loss.