150 XR6, will factory jets run worth a darn at 6000 feet elevation?

[Ron V]

Thinking of taking the boat out west but have never run any outboard above about 700 feet, so I don't know what to expect. Motor is a totally stock 150 XR6 (2005 model). I wouldn't care about performance since it would be mainly for sight seeing. Just not sure how rich it would really run. Will it miss, foul plugs constantly, etc? Or just not rev out like it should? It has the 1.87 gears and I know they sold 2:1 high altitude gearcases, so there must be a considerable difference. Thinking of Flaming Gorge Reservoir in Wyoming (~6050 feet) or possibly Lake Powell (3700 feet). The motor turns a good 5800-5900 rpm here, what would I expect out there with the same prop? Thanks.

[SRP71]

Hi, I can give you a little help and tell you my experience with high altitudes.

Where I live the altitude is 4500. I have been to Jackson Lake which is 6750 and I have also been to Powell approx 3700 as well as Lake Mohave 800?

I cant give you jet sizes for your motor as I run a Evinrude 235 But I can tell you how my motor did run at these altitudes.


The chart for my motor at sea level is 65C for mains but I run 67's due to early style heads cut .020 Mids are 31M and Low 36M.

3000 to 6000 ft is:
Mains 60C, mids 33M, low 30M. I run 61Cs for mains and it runs fine for altitudes from 3500 to approx 4900 ft.

6000 ft to 1000 ft is 57 C mains, 35M mids, and 27 M lows.

At Jackson in Wy I did re jet the mains for the above 6000 ft altitude from the jets I run for altitudes > 3000 ft and it was still on rich side. I run a 22 pitch stainless and it was considerably slower out of the hole. Pulling a slalom skiier was really slow but possible. It really load up at idle. Fuel consumption wasnt bad. If you idle a lot like (like getting out of the Marina) you will wish you would have re jetted idles if you dont.


I made a trip to Lake Mohave and re jettend the Mains, and mids and the boat was an absoulte rocket! The boat would lunge out of the hole and would almost pull me over my ski in less than 5 ft if my wife did WOT take offs. I could have easily ran a 24 pitch and had the same RPMS and hole shot that I do at 4500 ft.

The Trip to Lake Powell I ran sea level jets because I thought the lake was < 3000 ft. The idle and mids were set up for the altitude around my area (4500 ft).

I could tell it was too rich by two results (excess fuel usage vs HP and Not reaching top RPM) Found out the hard way that sea level mains was too rich. Baot would still take off but man did it like the fuel. WOT at Powell vs where I usually run WOT for approx same amount of time in gas consumption was considerable.


Flaming George and Lake Powell are both great!! Powell has very nice warm water in summer and fall Flaming george water is a lot colder. Powell is very hot in the summer and you wil go though a lot of ice and water there. Flaming George air temps arent bad.

I really prefer Powell but it is so huge and depending on the time of the year it can be extremely busy. We were there in Oct (Off season) and the Lake was very rough in the main channel and marina. Once you got away from the channel and into a cove it was great. Down side is you do a lot of driving to get back and fourth from the marina. Large waves sometimes 3 to 4 ft. Very scenic and best enjoyed with the use of a house boat and ski or speed boat.


Gas is expensive over 3.50 gal for reg at powell in Oct 2007. Not sure about Flaming george. It would be worth it to re-jet. Other wise you will be amazed how much fuel you burn and the power loss will be noticed as well as poor idle and hole shot.

Flaming Geroge is fun and scenic as well. Planing on a trip there this sept.

I envy you guys who have all of your favorite lakes at the same altitude. I can vary so much its really a pain. Going to try this as an soultion to changing jets all the time. Worked extremely well on my sand rail so I thought its worth a try.. http://www.thunderproducts.com/dial_a_jet.htm


Good luck and have fun which ever lake you choose. Sorry I dont have your motors jet table but I bet someone else on this site does.

Scott