Kawasaki Forums - klx250sf re-jetting questions

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- - klx250sf re-jetting questions (https://www.kawasakiforums.com/forum/klx-250s-71/klx250sf-re-jetting-questions-37656/)

Quote:

Originally Posted by alexb123 (Post 469385)

Im new to this whole bike modding thing and i have a few questions. I just purchased a Big gun evo slip on for my klx250sf. now i know that my carb is going to need some attention. Is it really necessary to buy a 60 dollar dyno jet kit, or should i just buy a new main jet? Also, if only the main jet needs replaced, what size should i get and where is the best place to purchase them?

You can just buy new main jets. But one of the biggest values of the DJ kit is the needle which is much better than stock. At least it was for my bike.

Quote:

Originally Posted by eyyopomps (Post 469421)

theres definitely more top end, but I almost want to say I had a decrease on bottom end..

Ok thanks.

I got a big increase with just the pipe , when I jetted it ran a little better but no performance increase.

if i do go with just main jets....what size should i get and were is the best website to get them from?

Quote:

Originally Posted by Brieninsac (Post 469386)

I don't know about the Evo slip-on, but with my FMF they said you don't need to rejet if that's your only mod. So if that's all your doing I'd try it first and then decide if you need to rejet.

I'll let others advise you on a new kit or not. I will say the kits also include the needle, spring and spacers.

I paid under $50 for my DynoJet kit. I would highly recommend buying the kit, over buying individual parts.

For a few extra bucks, you’re also getting SUPPORT! I figure I got the parts FREE, as I have emailed DynoJet twice to get specific (high altitude) jetting instructions from them. Their engineers saved me countless hours of fiddling with my own guestimated setups, and countless trips to the dealer to buy "experimental" parts!!!

FWIW, I jetted mine before getting a pipe. I noticed a HUGE difference from re-jetting, and adding a KDX200 snorkel. Sad to say; I noticed VERY LITTLE difference when I added my slip-on pipe. The BIG GAIN was in jetting it. (If my new exhaust didn’t sound so cool, I’d seriously regret dropping $300 on it.)

Quote:

Originally Posted by alexb123 (Post 469622)

if i do go with just main jets....what size should i get and were is the best website to get them from?

You need to change the needle too. The main only affects 3/4 to WOT. The needle controls @1/8 to 3/4 throttle.

thanks for the input guys. After that i'll probably just get the dynojet kit.

I just did the dyno jet kit to my bike, I did a full fmf q4 exhaust before the jet kit but it didn't seem to do a lot. I ended up buying the jet kit with the uni 2 stage filter. Its best to just get the jet kit because it will let you decide between the stage 1 and stage 2 and the different jets depend on how many mods you want to do. the kit also comes with the adjustable needle with the new spring and I had to run the clip on the needle 1 notch lower than it said on the instructions. Overall, it woke up the bike pretty good haha

My bike keeps evolving. I've done most of the same you all have done and it improved about the same as everyone has described. Then I remembered a klx'r that removed the backfire screen in the air box. The improvement amazed me. I guess we'll keep talking and learning from each other. Thanks for all your post's. Onward.