I am a fellow Aussie KLX 250 owner i have the 09 model and followed west oz recommendations. The only difference was i purchased the KLX 300 needle as i could not get my bike to run smoothly with the stock needle with the spacer (with the airbox lid removed) found it pulled much harder with the 300 needle.
I am running a fmf q4 and powerbomb purchase from USA total price all up for header and can approx $640 including freight.
38 pilot and 138 main it does run a little rich put i can live with that.

 

Interesting. So if you get the powerbomb header pipe (I presume you go for the KLX250 one?), do you get the KLX250s FMF Q4, or do you still stick with the KLX300 one?

And is the KLX300 needle the reason you're running a little rich? Or is it the 138 main jet? Oh, and are you running a stock air filter, or something like a twinair?

 

OK, so I was just back at the dealer and had a closer look at the 2010 KLX250S they'd fitted a Leo Vince X3 to. Took some pics too and you can see that the header pipe is a much larger diameter than the Leo Vince Slip-on (well, I would technically say "slip-in", but anyway ). And to back up your assertion that the Aussie header is about 1" longer, take a look at the second pic where the muffler is actually touching the indicator!

 

Yup. The header is too big for the Leo' that is designed for the USA spec KLX250S. You need a muffler designed for a KLX300R OR a full system for either model.

BTW, they can only get away with fitting it all is because the Leo' has a sliding clamp for the muffler. If it was a Muzzy or FMF it wouldn't fit at all.

"Bodge! I'll leak in 500 km."

 

Yeah, it was just nice to be able to confirm it on the latest model KLX rather than taking a blind punt and hoping to get the right slip-on.

I would presume you don't think it's worth going for an aftermarket header pipe given we get the KLX300 header then? (and because you just have a slip-on)

 

Well, I took the leap today. After confirming authoritatively with the dealer that my 2010 model KLX250S has the exact same header as the US 2007 model KLX300R, I went ahead and ordered the FMF Power Core 4 Slip On Exhaust (SKU: 042000) and the Dynojet Stage 2 Jet Kit for Kawasaki KLX300 (SKU: 2206) from JC Motors this evening. I've also ordered the Kouba screw.

So now I just have to wait for them to arrive, then clock up my 1000km's so I can have my first service and do the mods. Really looking forward to the extra power!!!!!!

 

Let the real fun now begin.

 

Woo-hoo!!!!!!!!! My slip-on and dynojet kit arrived today. MUCH quicker than I expected.

I also went out and bought a #38 pilot jet and 13 tooth front sprocket this weekend, to be done at the same time. The kouba screw I ordered is out of stock so they can only ship that to me next week. Annoying as I would have like that put in at the same time. Guess it's not a show stopper though.

I don't think I'll have the patience to wait to find someone to tech me how to rejet, so I am going to get someone else to do it. With luck I can get it sorted before this weekend!!!

 

Just set the fuel screw at 2 turns out from lightly seated. It'll be a good baseline setting for the #38 pilot (until you can fine tune it while the bike is running and warmed up.)

You could always make a 90 degree screwdriver from a cheap driver from Supercheap et al. Vice and hammer will do the trick.

Getting the front sprocket off requires more of a quick snap action on the powerbar and sprocket than constant pressure. Lock up the rear wheel and then give the bar a good quick snap. (Someone sat on the bike with the rear brake applied will be the easiest way to lock the rear. Drop the tyre pressure in the rear to (10 psi) to aid wheel grip to lock the chain .

 

Hey Arctra
Where abouts in Sydney are you and who are you getting to do your work. Also where did you order your jets from.
Cheers