hello guys hope you can help me out here as i am stumped!!! i have an 04 kfx700 bike is great so i thought i wouls add a few things to the mill , as follows new yoshimura dual exhaust complete kit . erlandson performance kawasaki cluthch kit, dyno jet stage 1 carb kit , here is the problem the stock jets are 138 front , 140 rear (thats what jets say on them ) i put the dj124in the front and the 128 in the rear with the new needles bike has awsom low end but soon as you crack wide open the bik just pops and falls flat on its face like it wasent getting enough gas and the dynojet kit jets were visablely smaller than the stock ones buy far, so i took them out left the dynajet needles in and put stock jets in it and i runs great !!! but i figured with the mods i did i would need bigger jets over stock not 14 sizes smaller in front and rear stock front is 138, dynojet front is 124 , stock rear is 140,dynojet is 128 that is the bigges they gave me can you guys explain this to me??? or give me som things to try th jets in the kit were 116,118,120,122,124,126,128,130,134,138 any suggestions?????

 

why did you put smaller jets??? you got an exhaust so make them bigger than stock not smaller. bigger = more fuel.

 

Welcome to ATV Connection. First off, the Dyno Jet kit classifies their sizes differently than stock. A 124 dj equals a 138k, and the 128 dj equals a 142. If I were you, I would put the 134 and 138 in and see how she runs. The 134 equals 148k and 138 equals 152k. My bet is you will be a touch on the rich side, so you may want to cut a 2" hole in the front of the air box and run a snorkle for increased air flow. You also want to back out the mixture screws 2 1/4 to 2 1/2 turns. Use the search and type in your problem, as this topic has been posted a number of times.

You also have a PM.

 

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Jetting is a pain!! with my setup I'm running 138F/142R Keihin Jets and went back down to the #40 Pilot jet. Though my bike seamed more torquier with the bigger jets, my plugs were completely black and my bike puffed black smoke at idle with the mixture screws turned all the way in. You could smell the rich mixture and could not stay in the garage more than a minute without getting light headed.

I'm still testing and tuning. Be sure all your vaccum lines are properly connected and your carbs are not leaking air on manifolds.

Sounds like you need more air. Do a Plug check/throttle chop. IF plugs are black you need to lean your machine . Was told by local mechanic that Raising your needles from the 5th to the 4th, 3rd, 2nd, 1st clip/notch can lean your machine 1 jet size for fine tuning. If you're not in the ballpark and plugs still black Put the 138 in the rear and go with the next size down on the main jet in front and test and tune again. I just wish there was an easier way to get to the top carb screws without taking the filter housing off.

Replace you carb bowl screws with metric allen heads (.04 x 12) from your local hardware store. If you remove your fuel petcock and coil bolts you can get to all bowl screws from right side of ATV.

 

thanks for the qwick response guys !!!!!!!! you guys are awsome its great to see people who are willing to spend alittle time to help a guy out i will try the jetting process tomorrow and see how it goes and buy the way, the ram air scoops on the nose i see on some of the kfx700s are they functional and do they work good or do they give too much air or are they for looks only???? one last qwestion i have stock air box still, what should i do besides k&n air filter and drill hole in it ??? if so where

 

Check out 700v.com.