hello you fine people any suggestions for a upgrade pipe that has a lambda sensor or how to get around that, ? 2012 bike just starting to tinker and change stuff now. andy

 

No advice on Exhaust. But did you do the clutch switch mod yet? How to soup up KLX250 EFI the easy way - Bike Chat Forums

 

Welcome to KF.

+1 on clutch mod.

You can buy any exhaust with or without an 02 bung for your EFi bike & this is how.

Put any exhaust you want on your bike by plugging in a 02 sensor eliminator (lambda) by-pass unit. It will also trick your ECU into running at it's max richness, which is a nice bonus! The lambda sensor on the klx is only there to keep the bike running lean enough to pass emission tests!! Don't be scared to chuck it in the bin.

Oxygen o2 sensor eliminator Kawasaki KLX250S KLX 250 S/SF EFi | eBay

I personally use an FMF Q4 & i'm very happy with the sound & unrestricted power.

Beware the TwoBrothers exhaust looks great but is ridiculously LOUD.

 

thanks for advice, ive done the clutch switch thing now start looking at pipes. thanks for all the help andy

 

Welcome Andy!
I think Joel covered everything in his post
I went for the powercore 4 its was loud but i had to tone it down with a quiet insert, looks and sounds great.
Although after 12 months ive still never got round to doing the clutch mod. any improvement?

 

You didnt do clutch mod yet??!?! Its a huge improvement. Way bigger than exhaust.

 

Serious????

I'm going to have to do some reading...

 

Stock KLX250 EFI is restricted in 4th, 5th and 6th gear. It will not pull over 7500 rpm. Clutch mod gets around this restriction and allow the bike to rev freely.

 

Sorry for posting to such an old thread, but I have a 2018 KLX250 US EFI. Are you saying all you have to do to mount the FMF Q4 is to use the 02 sensor elimator. Do you need to mod the airbox as well? Do you have to update the maps?

Thanks,

 

Bolt on the new exhaust and fit the o2 eliminator that's all that is required, no need to remap unless your installing a big bore kit.

Airbox snorkel and lid can be removed for better air intake, but that's optional.