Mountain Viper Jetting Discussion

stewstang

New member
Joined
Feb 24, 2016
Messages
12
Location
Nebraska
Bought my Viper from a guy with a few odd (to me) settings with what I've read off of this forum.
This will be for a 162 track, 19-40 gearing and slp pipes, 7tooth drivers. Yes i should go off of SLP's instructions but we all know to take them with a grain of salt. Elevation of about 9-11,000 (snowy range wyoming)

Air Screw of 2 turns out
1.5 on the needle (
52.5 on the pilot
145 main

IMO
2.5 turns on the air screw
needle setting of about 3 (2 washers on the BOTTOM of the e-clip)
pilots seem fine maybe lean
main seems fine from last outing from wyoming when doing a plug chop.

She bogs real hard if you stab the throttle and will die if you hold it wot but will take off if you slowly bring throttle in (making me believe the pilot and air screw are set too lean but theres a lack of air that high up)

Any input would be appreciated.
 
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I just leave the sled setup for mountains (according to what jetting the previous owner has wrote down) i dont get enough snow around here to enjoy it down here. So i ride in 9000-11,000 ft only. Otherwise here in nebraska is around 2000ft and i would jet my mains accordingly.
 
Just has the bog on take off (need to try turning the choke on while using the throttle) but otherwise it seems fine-ish. Ive read that vipers need more than just 1.5 on the needle (cruising trail part) otherwise they like to burn up. Ive gotten to take it out there twice now and havent messed with any settings yet.
So the concerns are, are the needles set up too deep? the only actual way to find out would be to trail ride and do a plug chop.
Viper bog has to deal with the fuel screw under the carb and pilots? add fuel to get that to go away.

Just confirming a few things before we head out next week and would rather spend more time on the carbs here than up there.
 
I ride around 5k-6k elevation. I have SLP triples and flo-rites cut into the dash (cold air intake). I'm running 155 mains, a bit too rich still, but safe and doesn't burble/gurgle. I have my needles at 3.0 (stock setting). My pilots are the stock 45's, but I have the fuel screws out 3 turns.

I think your mains should be pretty close.
Your pilots are bigger than I'm having to run, yet you're riding at quite a bit higher elevation. I think they went too big on the pilot jets and then leaned out the needles to try to compensate for it.
I'd try stock 45's for pilots and about 2-1/4 turns out to start on the fuel screws (they're fuel screws not air screws btw).
Then I'd try about a 2.5 setting to start on the needles, but bet you'll end up at about 2.0 maybe.
 


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