Can anyone help me with jetting. I am at about 1200ft above sea level. Thanks

 

Quote:
Originally Posted by Stunt****
G'day,

Aplogies in advance if I'm hijacking this thread...I'm new at forums and fairly new to bikes in general.

I bought an 09 KLX250s a few weeks back and loving it.

The problem: Kawasaki fitted a Two Bros M7 exhaust on the first service and derestricted the carby and air box (filled slider, removed snorkel, rejetted). Was producing heaps more power as you would expect but not running the best. Occasionally died when opening throttle from low revs, fuel economy went from 160km/tank to 120km/tank and was not outputting as much power when hot (this last one might be normal?). Also the exhaust became stinky and whenever I walked indoors after a ride I smelled like fuel.

I did some research online and found that in the older model (06-08) the standard jet size to use with a perf pipe was #128, N1TC needle on second clip and 2.5 turns out on the mixt screw. So I asked the shop what they had put in and apparently they used a #138 with needle on first clip because they didn't have a #128 available.

OK so I took the bike back to them, explained that I suspected it was running rich and asked them to try the above recommended setup.

"Expert" *&%^%^% mechanic them looked at the plug, determined it was too lean and thereby fitted a larger jet! So now it's got a #140 and it's running even worse!!!!! So much black powder coming put the exhaust that after 100km of riding I can't even see my rear indicator anymore, it's so covered in soot! Performance wise there has been a noticable loss in power at low revs, it's running rough (occasionally missing and jerky) in mid range rpm and doesn't pull through the high rpm's as fast as it used to. It's also a bit harder to start. Don't get me wrong, it's not running like a complete pig, but it's not right all the same.

So what should I do now? There's a dyno down the road at West Coast DertWerx...should I fork out the cash and let them work their magic or take it back to Kawasaki AGAIN and beg them to put a smaller jet in it this time?

Note: I have heard that different carby manufacturers jet sizes aren't the same. ie a 128 dyno jet isn't the same as another manufacturers size 128. This has only confused me more...

So...anyone with an 09 KLX250 who has had similiar experience, or anyone who's knows more than the "expert" at Kawasaki, PLEASE HELP!

How are ya mate.
I'm in Doubleview and have an 07 with the Two Brothers M7 with close to perfect jetting. #138 Main is the way to go (stock is #132.) Bike pulls really hard on WOT from about 4500. #40 Pilot is good for the midrange and use the stock N1RX needle (Aus model only) as is with the stock air filter. If you have a Twin Air or the like, use the brass washer (the one that comes with the N1TC KLX300 needle) to raise the stock N1RX needle about 1.5mm.
Fuel screw 1.75-2.25 turns out from lightly seated.
Let me know how you go. (All the jets I used are OE Kehein.)

 

Hi GG, use the search option and look for something called mods, jets and clicks (or something like that), you have a bunch of different set-ups there. Good place to start!