Elevation

herb

New member
Joined
Dec 2, 2004
Messages
47
Age
51
Location
Saskatchewan
Can someone tell me what carb and clutching changes need to be made for 6000-8000ft. It has low elevation setting now. gearing will be 20/38.
 

what sled, what track, is it stock? What temps? Also, if you can, gear it down more, alot more. ===SRXSRULE===
 
2002 viper extended to 144 /2 inch totally stock. not sure of temp but time will be end of feb so i am assuming not to cold.the stock gearing is 22/38 ,how much can i go just changing the top gear?
 
So you have 8 tooth drivers in it then? If it does, then I would run yamahas set-up for a stock Mt Viper. ===SRXSRULE===
 
I run 20/38 (1.90) with a 1.5" 136" in the mountains, works good with the type/style of riding I do. With a 1.5" track, there is a fair amount of track spin in the mountains , so I can get away with taller gearing. With 8 tooth drivers this would work out to be 2.14. Which should work OK with a 144" 2" track, depending on the type of riding you want to do. If you want to do a lot of high marking then you could probably gear down a tooth more. If you gear down more, I would go with a 39 tooth bottom gear, instead of a 19 tooth top gear. You start to loose efficiency if you go to small on the top.
This is what I ran in mine when it was stock, at those elevations. MJ 147.5 (146.3 for temps above 10*) needles at #2 position, (1/2 position leaner then the chart) stock pilot jets, fuel screws at 2 1/8
For clutching 3.6 grams in the heel, .8 grams in the toe, with a green secondary spring at 70*-80* should get you close. If it's over-reving on the top end, 2.7 grams in the heel with 2.4 in the tip works real well. Straighten's the shift out with the 8EK weights.
If your going to be spending much time at the higher elevations, pulling a couple of layers out of the head gasket will help throttle response. Then run good premium fuel.
 
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