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CVK40 Jetting

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Hey all,

Just installed a CVK40 last weekend, and wanted to post my results.

Bike: DRZ400SM
3x3
Yoshi RS3
K&N Air filter

Carb: CVK40 from a 2014 KLR650

Needle: came from 2144 DynoJet kit, installed in clip #4 position.

Jets: 40 pilot, 148 MJ

Drilled out vacuum slide to maximum clearance.

Elevation: 500 ft

Air screw: Screwed it in all the way, then backed it out by 1.5x turns.

Used the flexible idle adjuster from the BSR36

Runs pretty well, have had no issues with it so far. I'll get my wideband onto it to measure the AFR, but my guess is that it's on the richer side. My old BSR was tuned to an AFR of around 14.4-14.5, and I would get snap crackle pop from the exhaust fairly easily. With the CVK40, I barely have any pops at all.

Installation was easier than I expected. I pivoted the subframe to do it. Carb on the engine boot, installed the cables, wriggled it onto the engine. Longer screws were needed for the clamps. Installed the airbox boot, then pivoted the subframe back to get the airbox back onto the boot.

However, I forgot to modify the cable bracket for the pull cable, so wide open on the handlebar comes up short of about 7 degrees from fully opening the butterfly valve on the carb. I am still running the return cable.
 

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Ditch the return cable (don't need it).  You should be able to get WOT.   While the tank is off, take up cable slack at the carb.  Take up the rest of the slack from the cable adjuster near the twist grip.  Leave a bit of free play.  Motion Pro R1 or R6 replacement throttle tube will help too.

Welcome to the CVK clan.

 

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3 hours ago, 38super said:

Ditch the return cable (don't need it).  You should be able to get WOT.   While the tank is off, take up cable slack at the carb.  Take up the rest of the slack from the cable adjuster near the twist grip.  Leave a bit of free play.  Motion Pro R1 or R6 replacement throttle tube will help too.

Welcome to the CVK clan.

 

Sounds good. I actually have a Zeta Quick turn throttle sitting on my desk right now, just waiting for my grips to come in.

Unrelated: forgot to post up that I am currently getting about 50 mpg (refilled 1.35 gallons at 67 miles indicated on stock odometer. 

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3 hours ago, LuckyLucky said:

Sounds good. I actually have a Zeta Quick turn throttle sitting on my desk right now, just waiting for my grips to come in.

Unrelated: forgot to post up that I am currently getting about 50 mpg (refilled 1.35 gallons at 67 miles indicated on stock odometer. 

Might just go down in the mpg's once that 7 degree issue is fixed.....hahahahaha, you're going to love it once that quick turn is installed.......and yeah, welcome to the CVK club bro!!

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