Viper with CPR pipes, head mod, atacc, etc.....

..SNAKEBIT..

..SNAKEBIT..

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Viper with CPR pipes, head mod, atacc, etc.....

I ride flat land like Iowa and also go out west with it was wondering where any of you were at with the carbs
holtman Atacc installed like rev*baron's in tech
jets 165 165 170
pilots 47.5 47.5 50
needles 3.5 3.5 4
seems real blubbery till @ 6500-7000 then it takes off and runs some times it will only pull 8500-8700 rpm thinking its shifting out to fast and wont back shift BUT I think I need to fine tune the carbs closer first so the power is right
8dn-10 weights
50-40 with green spring @ 70'
this was on my first ride saturday Dec 10th
need to check plugs and wash monday at shop, but was sitting at home wondering what other people ran, and where I should start? mains, pilots, needles, or clutching????
thanks for any input Marty

ps have checked wash and exhaust side of pistons are clean at the exhaust port @ 1/2" in from edge and @ 1/3 around edge (like a big smile)
 
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run 47.5 pilots across the board, All needles at 3.5, jets 165,165,167.5.
start with your atacc on the rich side and adjust from there. Wrap the secondary spring more to get the rpm's up, then check jetting, When you lug CPR pipes you get that wash. Exhaust isn't fully pushing the charge back into the cylinder. Maybe take some weight off the primary if you still can't get the rpm's.
 
Seems pretty close

Sounds close to me. What about the fuel screws? Why dont you check wash and consider adjusting the fuel screws? If you have them at 2 1/2 to 2 1/4 try taking them in 1/4? Just a thought.

Madmatt
 
is 3.5 position 4th groove one washer top & one on bottom?
or 3.5 position 3rd groove both washers on bottom?
sorry pilots are 47.5 47.5 50
 
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Mine ran blubbery on the bottom end too when I had the CPR's on. I had everything to Jeff's specs too. I didn't like them in the trails. If you get the Attac working right, hopefullly that will help. Without any help like that or a Tempaflow, they seem real finicky to temperature changes.
 
why are you going so rich on the mains? i thought when you run the attack on there that you have the jetting set for the coldest rising and lowest elevation you run without?without the attack i ran the 47.5 and the 50 pilots and i ran 160 -160-162.5 mains and it wa s godd at -30 below, also it was rich on the warm days.i put on the attac but never rode it yet, now you have me concerned
 
I thought people said 160 -162 was only good for +10' ??????
that is why I am trying to see what others are running with Atacc'c or Tempflow's
let me know what you think when you ride it
I also read a guy ran 156 jets when he was out west 162 on flat land
 
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i went with jeffs specs, and what he told me was it was good for -20,c but i also have the head mod
 
OOp's sorry I was running 165's across the board, with 3.5, 3.5, 4, on the needles. Thats what looked good piston wash wise, with an atacc. my elevation is around 800'.

sxrsist, what's your elevation? if your around 3000' that might be a good setup for you. I know if I had 160's where I'm at in below zero weather she would be getting close to lunch
 
we are at 1000 feet ballpark also, maybe il try that, what was your setup xxx, thanks, pilots and all
 
I know you are supose to run stagered pilots but I did'nt and it was fine.
ran 47.5 across the board pilots, with needles @ 3.5, 3.5, 4
and 165 jets across the board, atacc screw on the lean side slightly.-25 below farenheit setting. maybe jeff was talking about celsius? I was using megapowers with srx base gasket. that setup will........
 
triple xxx what pilot jets are you running??
holtman Atacc installed
jets 165 165 170
pilots 47.5 47.5 47.5
needles 3.5 3.5 4
pto & ctr 4th groove washer top & bottom / mag 4th groove both on bottom
fuel screws 2 2 2.25
 
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