What is the difference in Elevation going to make a difference?

[needforspeed]

I live in NJ and my elevation where I ride is 158 ft above sea level. Now I vacation at a spot called Deep Creek Maryland which is up in the mountains about 10 miles from West Virginia. The elevation there is 2400. Is that a big enough difference to worry about my jetting? If I were to bring my Doos on Vacation with me? The boat seems to run fine and the truck but they are big 4 stroke engines. I am just thinking out loud here.......:willy_nilly:

 

[Dr Honda]

nope... normally you won't see a problem until you get over 3500'. And even then... you may not have a real issue until you get above 6000'.

When are you going? The wife has been wanting to go to deep creek.

 

[ski-d00]

As a general rule, for every 1000 feet in elevation climb, you will need to lean your jets by 1%. So, your 2000 feet change should have a 2% leaner jet but Mikuni jets aren't that close to each other, they're about 4% between them so your current jet is the best jet. If you were to go higher, say 4000 feet, you should jet down 1 size.

Temperature differences will also require jet changes, but with SeaDoos we all seem to ride between 70 and 100F which is minor when compared to snowmobiles where one day you can ride at -30F and the next could be 40F.

It's also interesting that you will lose hp with elevation climb and temp increases that can be substantial.

 

[Bills86e]

Low octane fuel will work much better for you in high elevation than super.

 

[Dr Honda]

It's also interesting that you will lose hp with elevation climb and temp increases that can be substantial.

That's known as "Pressure Density" and "Altitude Density."

Back in my younger days... a buddy and I took a Cessna 182 up to Big Bear Mt. (Runway was around 8400') When we decided to leave... (85 degree afternoon) we didn't have enough power to actually get off the runway !!!! We had to wait until the temps dropped into the 70's to leave. (about 9 pm that night)

FYI.... 1000' elevation = 3 degree temp. SO... by waiting, it was like dropping the runway elevation by 3000' ~ 4000'.

 

[needforspeed]

nope... normally you won't see a problem until you get over 3500'. And even then... you may not have a real issue until you get above 6000'.

When are you going? The wife has been wanting to go to deep creek.

the week of July 23rd....we will be there from sat to sat

 

[needforspeed]

Low octane fuel will work much better for you in high elevation than super.

well that is a plus because that is all they sell on the lake.....lol

 

[Rotor13B]

nope... normally you won't see a problem until you get over 3500'. And even then... you may not have a real issue until you get above 6000'.

When are you going? The wife has been wanting to go to deep creek.

This makes sense, I plugged in my compression numbers for both my ski's in an equation that was suppose to calculate compression loss every thousand ft. I'm close to 6000' and 150psi motor at this elevation would show about 135psi or so. This seems to corulate with my compression tester. Is this right or am I missing something?