I just dropped about 900 bucks on up grades for my 06 KLX250s. I bought GP1-dual sport tires. I ride on the road 90% of the time. The 4x's that I had it offroad! Man what a hand full! I went out with some Beefed up racing quads. They make it look so easy. I was on the edge of being out of control! But, practice makes perfect. Now back to the upgrades. I got the ProTaper Contour handlebars as mine were bent from it falling straight over in an asphalt parking lot. And after that I have dropped it 12x's in the woods.

Ok here is the million dollar question. I'm at 750 ASL and the highest point in Indiana is 1250 ft ASL. I just bought a KLX300/250 94-07 slip-on Q4. When going to mount it I noticed that is was short and wouldn't work with my stock header. So, I found Four Stoke Works mention on here and bought a KLX300 header. It is on the way, along with the T handle Kouba screw. I also have the KLX300 dyno jet kit. I know the direction say start at a 128 main from the 3 notch from the top..... but I have also heard from OZ to start at a 132. I was open for suggestion because I really don't want to do it more than 2X's. I was thinking about going up to a #38 pilot. For low end power. Any help would be great.

 

Dont increase the pilot jet, i did, then went back to stock. I have the 128 jet in mine, but mine are kawasaki jets not DJ jets... a 128 kawi jet is different than a 128 DJ jet. I know there was a chart somewhere that shows what equals what... Mine runs great with the 128 jet. Cant help ya with the DJ jets though... do some research.

 

Not a bad idea to research something on here before you buy it.

https://www.kawasakiforums.com/forum...ad.php?t=27511

I would start with a 132 main.

 

I haven't really read much on the Kaw jets weather they were big or what. I have been definitely looking. Thanks for the advice on the stock pilot! Think I will start at the 132 main. I hope it works. Not fun taking it all down again. But, it will be good practice! Thanks for the input guys!

 

Jetting recommendations are tough due to all the variables involved. I had all the exhaust, airbox, and jetting mods done to my '06, and it ran perfectly. I recently installed a 300 kit and expected to need increased jetting in the form of a pilot jet, main jet, and maybe a needle position. It turned out that I didn't. The bike had a full Muzzy exhaust, opened airbox including screen removal, Twin Air filter, 300 DJ kit with slide drilled, 128 DJ main jet, 35 pilot, and DJ needle with clip in 3rd groove. My jetting was perfect in 250cc mode, and it ended up being perfect for the 300 kit. Surprised me for sure. The bike will pull redline in all 6 gears with 14/47 gearing, has noticeably more power, and still gets great fuel mileage. I think many are tempted to go too rich on their jetting when doing mods. Obviously you don't want to "hole" a piston screaming down the highway at 7-8 thousand rpm with too lean jetting, but running a nice, clean fuel mixture makes the bike run better overall IMO.

 

Very good info on the FSW header! Will keep my eyes open for the the oil line issue.

 

What is your elevation? How can u tell if it is too lean? You are right on the first you want to do is slap in the bigger jet. I guess I will have to leave it torn apart and ride it so I can get back in there. I won't think that the mpg would be very different between 128 and 132 jet.

 

I'm at about 1700-1800. I also did about 2 weeks at Moab last month with a couple of runs that went across 10,000 feet in the La Sals, and it carbureted very decently there. The guy I bought the bike from had a 132 DJ main in there with all the mods except the 300 kit. It had a very slight rich mid-throttle burble but would pull through it to WOT just fine. It was noticeably "sooty" at the end of the Muzzy muffler. I dropped the main to 128, and it ran more cleanly and smoothly.

As to detecting too lean a jet setup, you usually tell this by throttle response, plug reading, and by listening carefully for detonation or pinging.

 

FWIW I'm installing the same pipe, with the megabomb header. I'm also installing the NITC needle which I plan on starting at 3rd clip. I've cut my snorkle down, but am not removing it, or cutting my screen. Because of the last 2 points, I'm starting my jetting at a 130 as I'm at about 750 ABS and other guys with the same set up but cut out air boxes with out tops are running a 132. I figure I should be able to run a little less rich than they do as a result of not removing the lid and snorkle and screen completely. But as I'm waiting for the header gasket.. all this is theory till I ride. I'm also going to order the kouba screw asap. I'm hoping if it's too lean I can just bump the needle up a notch and or open my idle screw a tad. I'm with TNC on not overdoing it, right fuel/air is better than most fuel/air.

 

I'm cutting out the screen, no lid, and K&N filter. I might just run it lean with a 128 KLX300 needle 3 from the top. What is the worst that can happen? Hole in the piston? Then I have to get the big bore kit. Nah, just kidding! It silly to just tear up a motor like that. I want 12k to 14k before I attempt that! The base line is supposed to be 128 3rd notch from the top. I guess thats where I should start.