Hello guys, i've taken the plunge and signed up after browsing the forum for a while.
I bought my 2009 EFI KLX 250 in May last year, it is my first bike and it's pretty much standard up to now but i am now looking to modify to get more power and torque top end and in the lowers gears. I am only using this bike for on road use so i needed to buy some lowering links as i am lacking in height (5'6") and i have recently purchased some road tyres.
What modifications would you suggest? The 'cheaper' the better obviously.
I plan on keeping this bike for a few years so i am willing to buy some expensive mods such as exhaust in the future.

I must add i am pretty alien to this kinda stuff so i might need pretty basic instructions haha.

Thanks so much for reading.
Ant.

 

Hi Ant,

Welcome to the forum

I'm guessing you got EFi & not a carb, as your from the UK.

The 3 must do mods:
1) I'm thinking a FMF Q4 exhaust is probably the best power/sound to low(ish) noise ratio for keeping the Wigan boys in blue happy.

2) You don't have a carb to rejet but you can fool the ECU into running the EFi at it's max richness with a simple 02 sensor eliminator. This is a absolute must or your standard ECU setting will damage your engine by running to lean after modding.
Oxygen O2 Sensor Eliminator Kawasaki KLX250S KLX 250 s SF EFI | eBay I found one of many sellers of this device
A bonus of this device is, you won't have to fit/weld a 02 bung on your new Q4 exhaust.....because you have already eliminated it!!

3) Buy a kdx snorkel or just take off the snorkel all together but don't do this until the bike is running richer with the 02 sensor eliminator.

This is the basic uncorking of the EFi KLX....enjoy

When this becomes boring & you need another little boost. Print out the marcelino cam mod & take it to a good mechanic & it will be a very noticable boost in power. Do your first shim clearances at the same to save time & money!
https://www.kawasakiforums.com/forum...rcelino-35904/

 

I've been looking for one of these eliminators a for a while and I'm glad you posted that link.

I too have the EFI version of this bike and added the fmf powercore 4 slip on without the O2 sensor installed which I'm worried it will cause problems in the long run as you mentioned. Think I might get one of these ordered. Thanks..

 

Hi Ant

You don't live to far away from me welcome to the forum.
I had a similar issue when I first bought mine, far too tall.

Managed to lower the back suspension so it fits me fine now.

First performance mod I made was adding the fmf powercore 4 exhaust
This did make a noticeable difference.

I too use this bike for road use so looking for more visual mods myself rather than performance personally.

 

Hi Joel, thanks for the quick reply and all the advice. i am thinking of removing the snorkel firstly so i will order the sersor eliminator soon. Are there any negatives to removing the snorkel completely?
Also, like i said in the OP i'm not quite clued up on whats what on bikes and thats why i have come here, to learn. I don't know where the oxygen sensor wire starts, could one of you post a picture or describe where i start so i can follow the wire to the connector?

Many thanks, Ant

 

Hello mate, yeah i plan on getting the fmf powercore 4 at some point.

I just want to get the bike really fun and poppy to ride as it is just for the weekend really. So i want to get the maximum power/speed i can get out of it over time.

 

The 02 sensor is under your seat & swapping it out is going to take 30 seconds including the time to take the seat off! Like the clutch-by-pass mod, very easy.

Download the pdf manual for the EFi bike from this link:
http://dl.dropbox.com/u/7994391/klx250.pdf
Page 154 shows the 02 sensor & location.

Happy reading

ps. Just a thought as your putting on road wheels but the klx is a great nimble & capable off road bike but is very lacking as a street bike in the power department. As a road supermotard it is NOT a Husky or a KTM etc etc. I only pimped my klx out because there is no cheap/affordable secondhand market for mid+ sized motards in Thailand. Do the cheap mods above, if you even start thinking about bigbore kits or power commanders......STOP......sell it and get a 400+cc real Motard.....I would if I still lived in the UK.

 

If mine was strictly for the weekend id definitely go for the powercore 4 its quite loud but sounds amazing, i use my for the daily commute as well as a ride out so had to get a quiet insert for it, i posted a thread about it not long ago so you should be able to find it. there's a video there too that may help you.

The exhaust did add power/better performance.

that pipe was quite hard to get hold of actually i couldn't find one online from the uk, i had to order mine through rocket centre here in blackburn if you have heard of the place. Quite a decent shop as well

hope this helps

 

Thanks for the advice. I don't plan on spending mega bucks but i just want my bike to be as fun as possible within a reasonable budget. I will download the PDF tomorrow, cheers.

 

I do go to work (6miles) on it when the weather is nice but i have a car so tend to go in that. I plan on getting the exhaust when i have done all the other little bits suggested maybe even next year as i bet this nice weather won't last much longer haha. Once again, thanks for the reply.

Edit: i just saw your video on rivington pike, i have been there quite a few times and it is only about 20minute ride from me. That is a nice road and there is a few more decent roads around there. Have you ever been to the barn on a Sunday?