When i bought my fourwheeler it had a coolhead on it. im not sure what the dome sizes are but what sizes would be best for it?

 

I think 22 or 23 are stock sizing. I'm running 21 in mine. Personal preference the smaller the number the more compression.

 

But doesn't sea level and elevation matter too?

 

I don't think elevation will come into play when deciding what dome to get.
You will be required to change jetting with elevation, but your dome size should not come into play. The dome size simply determines how much compression you will have inside your cylinder, and will determine what octane the fuel needs to be to eliminate the possibility of detonation.

 

I beleive with elevation the compression is different. If you have a rocky mountain catalog it tells you the compression you will have with each dome at different elevation levels.

 

Elevation plays a BIG part in compression!
I'm running 180# + at 7,000 feet, sea level would be well over 200!

You need to keep that in mind when changing domes.

 

Hmmm..
I will have to check into this more......

If you have a compression ratio of say, 8:1, you are still going to have the same ratio at any elevation.

I know there will be a larger DIFFERENCE in READINGS on a compression gauge due to the effects between atmospheric pressure (14.7 at sea level, and less at higher altitudes) and the reading on the gauge.

Hey, if I'm wrong, at least I will have learned something! [img]i/expressions/face-icon-small-wink.gif[/img]

I will check check into this a little more.

 

Hey Jennifer, how far is whitesboro from odessa? Do u know where i can find the seal level for my town? What size of dome would u recommend for the machine i have? Would anyone know anything that's good for me to jet on my shee? I think it was jetted once but what would be a good jump on jetting.

 

At sea level a stock Banshee will have about 130 PSI of compression. You will lose 6 PSI per 1000 feet up in altitude you go.

For example, I am at 6300 feet and with stock heads I had about 95 PSI of compression. With coolhead and 19cc domes I am at 128 PSI. If I were at sea level I would be over 160 PSI with the 19 cc domes.

Compression RATIO does not change put measured PSI with a compression tester will change with altitude.

 

Well I'm north of Dallas about an hour or so. Elevation for Odessa is app. 2851 above sea level. You might call a local dealer or Rocky Mountain ATV and they should have the specs as to what altitude would provide which compression results.