#138 Keihin jet. :D
#138 Keihin jet. :D
I've been running this jet since my first mods on my KLX250H7 and have wrestled with the idea that is too large due mainly to the overwhelming number of posts on this forum from guys/gals that they are running a #128 main, a #132 main and saying the bike performs great. The thing is, my bike runs great too especially on WOT from 5K onwards. 
. Having just picked up this months issue of Trailzone, (AUS and NZ trail bike mag') I now feel somewhat vindicated about my choice of carb' jetting as their current testbike (KLX250S) has been jetted with a #138 main too. "Essential mods" are the words they use for the rejetting. They also advocate raising the stock needle with the appropriate shim and replacing the carb' slide (AUS owners only as Kawa' tend too drill holes in the AUS spec slide to meet noise regs'). They also removed the snorkle.
Some food for thought.
. Having just picked up this months issue of Trailzone, (AUS and NZ trail bike mag') I now feel somewhat vindicated about my choice of carb' jetting as their current testbike (KLX250S) has been jetted with a #138 main too. "Essential mods" are the words they use for the rejetting. They also advocate raising the stock needle with the appropriate shim and replacing the carb' slide (AUS owners only as Kawa' tend too drill holes in the AUS spec slide to meet noise regs'). They also removed the snorkle. Some food for thought.
Senior Member
Joined: Oct 2006
Posts: 3,106
From: Misawa Japan
1st Gear Member
I agree. This bike likes fuel and lots of it...as long as you don't restrict the air flow 
We even had a guy on this forum who was running a #140 with BG race core and no air box lid. He said he had no issues with it and loved the top-end pull.
We even had a guy on this forum who was running a #140 with BG race core and no air box lid. He said he had no issues with it and loved the top-end pull.
No airbox lid is the way to go down here. Where's the water. LOL
I may change down the #40 pilot to a #38 pilot (KLR650.)
She's a tad rich on 1/4 throttle.
I may change down the #40 pilot to a #38 pilot (KLR650.)
She's a tad rich on 1/4 throttle.
Senior Member
1st Gear Member
Joined: Aug 2008
Posts: 960
Well, thing is hes probably not that far off. I'm new to this bike and forum, but from what I can tell its like this.... he's in Perth, which is the west coast of OZ, so hes either at or near sea level, so he needs a larger jet for that. Plus I know he has a pipe, and no airbox lid. So if our U.S. issue bike comes with a #118 stock and run lean, with all of that he has to be on the nose right, and if hes a little rich thats ok, better than a little lean.
Jetting is like life, its better to be a little rich.
________
The Cigar Boss
Jetting is like life, its better to be a little rich.
________
The Cigar Boss
Last edited by JasonFMX; Mar 29, 2011 at 06:59 AM.
Senior Member
1st Gear Member
Joined: Apr 2007
Posts: 600
Not bad at all, that works out to 93 miles at reserve which is about the same as my bike with a #122 main jet, but I'm at 4,500ft elevation.
Senior Member
1st Gear Member
Joined: Jul 2008
Posts: 852
From: Austin, TX
That is what I get now, at stock. 400 feet asl.
I weight 200lbs naked and wear a helmet, crappy walmart hiking boots, tourmaster intake 2 jacket, socks, baby powder, boxer shorts, plain hanes t-shirt, and heavy canvas cargo pants. Just so you know.
I weight 200lbs naked and wear a helmet, crappy walmart hiking boots, tourmaster intake 2 jacket, socks, baby powder, boxer shorts, plain hanes t-shirt, and heavy canvas cargo pants. Just so you know.