I have to admit, I was going to take it off the bike and either toss it in the corner for a year or sell it .. it was just too jumpy and surged and bogged too much at the 1/4 throttle range, too rich in midrange, and too rich at top end.. I missed the smooth accelerating street-friendly cvk

After several days and having the carb on and off 12 or more times, I have it.. It accellerates very smoothly off the 0-1/4 throttle.. snaps your head back 1/4 to 3/4 throttle, and preserves all of your top end... the bike has serious attitude, is ridable on the street, and almost uncontrollable on dirt.. I would say this carb added as much a perceivable difference in power and torque as when I went from 250 to a 351.

At Sea Level, 55 degrees F - my final settings:
MAIN JET 127.5
NEEDLE JET 585-P-6
JET NEEDLE 9EBY01-51 (position 4) - 4th from the top
PILOT JET 22.5
PILOT AIR JET 1.0
MIXTURE SCREW 2 TURNS OUT
PUMPER NOZZLE SPLASHING OFF NEEDLE
PUMPER STARTS AT 1/8 THROTTLE AND STOPS AT 3/4

I had to richen the pilot/idle band, lean out the midrange and WOT
17.5 pilot jet was not rich enough to take the lean hesetation out of the 1/4 throttle band, so the 0.7 (smaller) pilot air jet did the trick, as well as raising the needle two notches

I highly recommend this carb!

Lets just see how she runs when the weather changes to 80-90 deg F this summer.. might get too rich

 

Pilot jet 15
NO idea how many turns right now. Idles stable hot or cold.
Pilot Air Jet 1.0 (stock)
Needle Jet P6
Needle Stock in stock position
Acc pump comes in about 1/8 throttle and out at 3/4. Sprays on needle.
Main Jet 125

Just the elbow of the KLX snorkel (rest of snorkel surgically removed)
Screen removed from Airbox
Stock air filter
Exhaust mod by me.

351 cyl.

Getting 60+ mpg and amazed.

Flat spot when cold just off Idle, goes away when warmed up.
Waiting for warmer weather to see how it runs then.

 

I keep going back & forth on wanting a pumper and not. One one hand they seem to be a PITA to dial in correctly. On the other, once they are I hear they're the bee's knees.

But then my CV works like a charm and I have no complaints.

And I really need to stiffen up my suspension, so I'd probably be better spending cash on that then the pumper.. AHH

I really need to try someone's 351 with the pumper to see the difference. Soooo... Who wants to lend me their bike!? haha

 

How sensitive are pumpers to changes in altitude? I live at 1600' but ride up as far as 8500'. I don't get any complaints from my CV at all, its just as lifeless at sea level as it is in the mountains. I'll have to do some searching.

 

Hey I can say they arent too sensitive to ambient temperature change.. 34 degrees out tonight.. didnt run too lean..

 

I want to know the difference in snorkel, air filter, exhaust, and altitude between TIGER and Dave.

 

My jetting is richer than both David and Tiger and I am running on a stock bore. Mine is perfect and pulls hard everywhere..... I have tried leaner jetting but the performance is no where near as good. Not sure why mine needs to be richer.

I run mine with no lid, backfire screen removed, After market filter, FMF P-Bomb header + FMF Q2 exhaust.

I also found when I had the CVK carb I had to run everything one step richer than Dynojet recommended???? It’s the Australian model so I don’t know if that has anything to do with it.

 

yea I richened up the bottom end and added more air tonight.. reposted the final settings.. I cant stop tinkering I love this

 

I think that is most of it. Mine ran great with no lid and a 135 main. With lid and snorkel mod, I ended up with a 125 main.

No doubt it ran better with no lid but I can't stand the noise. My son keeps telling me to put on a little K&N and ditch the airbox. Shock is in the way.

I don't have a clue about changes in altitude, Its flat here.

No doubt the pumper is harder to dial in, but once its there, just enjoy.

Don't forget I ride an SF on the street all the time. Most of my time is spent at indicated 62 mph. Just under 1/4 throttle. Twist the grip and the bike takes right off! That is with a 15/39 gearing.

I rode to work this morning, it was 32*f when I left. Snowing when I got there 20 miles later. Went in for breakfast, came out bike started with no choke and a really small turn of the throttle.

I have also noticed the vacuum sucks the slide when throttle is closed and I am decellerating. I have to be careful to turn the throttle so I don't get a lurch when the vacuum breaks. This is only coming off a fully closed throttle.

Tiger, I guess you did fatten it up on the low end. What are you getting for mileage?

David

 

Hotter ignition, you are at 35 deg total, we are at 25 deg total