Heyy guys after a long time! Last friday I took my bike for an emission test as I need to get it done ever year to renew my registration.. My KLX passed the test and I got the result.. They only check the Emission at Idle (1250 RPM) and at 2500 RPM.. The Result showed that at Idle theres a fuel wastage of 25.44% Per Litre and at 2500 RPM theres a wastage of 24.21%. What do you guys think I should do? Just forget it or?

My Jetting is:
38 Pilot/Needle on 3rd position/About 2.5 Turns on fuel screw

What do you guys think i should play around with?

Thanks alot!
Jamie

 

Do you have other mods to the bike?...pipe, airbox, etc? My '06 KLX250S with 300 cylinder, full Muzzy exhaust, and opened airbox only requires a 35 pilot jet. There are so many variables to consider such as altutude and such.

 

If the bike runs fine just leave it be. That readout is probably only relevant to their test criteria. Unless you're an engineer and know ALL the parameters of that test: Forgetaboutit!

 

sounds like there coping kkkalifornia and want you to run leaner and leaner till you burn up you motor. if you passed, just leave it.

 

25% above who's baseline? an automobile can get by with a little lean surge and an occasional lean misfire in one of the cylinders. Due to it's mass you are so disconnected you don't even notice it. Bike's you'll feel it so like to be a little richer than what today's standards are for emissions. That said, my bike also dials in better with the stock 35 PJ, and the mix only at ~1.5. YMMV

 

If it waste fuel at that low of RPM's, just turn back the idle fuel mixture screw. Should lean it up some.

If you pass the E/M test and you really don't care idle waste fuel, then let it be.

 

I don't know. I think it's fine to pursue exacting fuel mixture. It definitely may not be worth losing sleep over, but it's nice to have a carb running at the edge of perfection when possible. It also helps to increase overall fuel mileage and carbon buildup to some degree. That said, I'm not totally up on the emission testing results and what it means in the real world of carb jetting. My understanding is that it takes an oxygen sensor in the head pipe to really dial in a carb or a fuel injection system to perfection. Tailpipe readouts like you get in an emission test may not be the best way to analyze your optimum fuel mixture.

 

What was the barometric pressure that day? what time was it?
what was the air temperature? what was the engine temperature?
But most of all,,,, how does the bike run?
emission A/F ratios are much leaner than peak HP or torque ratios.
Personally, i would jet it to make the most HP/Torque, not to please the State emission regulators. You have a 250cc engine that needs all the help it can get.
25% rich mixture on your bike equates to a 2.5% rich mixture on a 2.5L car engine.
see this thread if you really are interested.
http://www.bristoldyno.com/tech/airfuel.htm

 

Did they give you a print out showing CO , HC, and NOx+HC ? You could have numbers that were fine for a year 2000 standard, but today your "wasting fuel".

 

Fuggedaboutit