So a couple of weeks ago I installed the dynojet kit, using the recommended notch on the needle, and the 128 main jet.

After a couple of weeks of riding it, I've noticed the following:

Initial takeoff is limited/not improved.. it's only once I get to about 15kph that it starts to pull.

When I decelerate, there is a faint popping.

When I'm cruising at a steady pace of 50kph, the engine feels like its ... inconsistant? like its dragging occasionally?

Are these all related? Is my bike about to explode?

 

Sounds lean. I would first try dropping the clip position down one to raise the needle one position. If that doesn't quite do it, then put it back to where it was before, and then go up to the next size on the main jet.

 

seen. will try that. cheers!

 

A 250cc on a 128 main jet is lean?! Factory jetting must have been just air burning.

Initial takeoff does not improve and will not improve with the stock carb. Pumper carb will solve that.

Decel popping, stock does it too. Pull the clutch in and let it coast. Or try riching the idle air/fuel screw to around 2~2.5 turns out.

Drag at cruise, could be the needle setting. Try adjusting the needle height before changing the main jet.

 

Yeah try playing with the A/F screw a bit. Mine runs perfect with the snorkel out and a 128 main... needle in the middle, about 2.25 turns out on the screw. With the TwinAir it runs even better, the plug looks pretty good. What's your altitude? I'm damn near sea level. Slight decel popping is normal, mine does it.

 

After you try the other suggestions, if they don't help go up one on the pilot jet. My wifes 09 responded well to a 38p with the kouba screw out 3.5 turns. But kouba recommends 'Do not run with the mixture screw farther then 2.5 turns out as it can and will vibrate out' so I went to a 40 pilot and 1.25 - 1.5 turns out. It helped remove the hesitation in the low to mid range. Backfiring on deceleration is lean - dj says to open mixture screw (as per dj trouble shooting guide suggestion #9)

 

Mines crisp off the bottom. #38 pilot and 1.75 turns out. #138 main though (kehien.)

 

Think this is the best solution.. fairly easy to solve as well!

Same. I look out over the harbour...

Where did you get your pilot from? My mixture screw is already at 2.5 turns out.. wouldn't want to go any more!

Would a new exhaust help the symptoms at all? And is #38 stock?

 

try the pilot jet jets 38 to 40 . should make a difference.

you guys are so lucky you can order stuff/pilot jets ect.

up in the great white north you cant,they dont sell to many

so they stoped bringing stuff in. i had to make my own pilot

jet!. not sure what size it is but it works pretty good now.

when in dought drill it out..

good luck

al.b

 

Kawasaki dealer part numbers:

p/n# 019-511 38 keihin pilot/slow jet
p/n# 019-512 40 keihin pilot/slow jet

35 pilot jet is stock

al.b Sudco dot com sells carb parts & jets/needles too