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opc · August 9th, 2011, 11:16 AM

Hi Guys,

I just finished my weekend project of installing a K&N R-0990 air filter and removing the Kleen Air system. The previous owner of the bike had already installed a full Yoshimura exhaust and re-jetted the bike to work with the stock airbox and snorkle.

Everything went really well overall, and the entire process was far less daunting than I had anticipated. In fact, I had the airbox out and the carbs fully re-jetted in just a few hours!

Here are my current settings which I started with based on someone with the exact same setup as me on the jetting database:

YEAR: 2009

INTAKE MODIFICATIONS: Airbox Removed, K&N R-0990, Kleen Air removed.

EXHAUST MODIFICATIONS: Yoshimura Stainless Full Exhaust

JET KIT OR STOCK?: Jet Kit

BRAND OF JET KIT?: Factory Pro Stage 3 Jet Kit

MAIN JET: 110 (FP)

PILOT JET: 40 (FP)

NEEDLE AND CLIP POSITION: 4th clip from top

MIXTURE SCREW SETTINGS: 2 turns out for both

ELEVATION: 230 feet above sea level

I took the time to re-sync the carbs once I was all done, and I adjusted the idle to be about 1500RPM.

So the result? Well, it pulls very well from about 6000 to 13000 (noticeably better than it did with just the exhaust and the stock airbox), it's about the same from 4500 to 6000, but the bottom end below about 4500 is now significantly worse than it was before. To get the bike moving quickly off the line I really need to get the engine revs above 4500 and then slip the clutch, where before this wasn't a problem

I'm hoping someone here can give me a good place to start in terms of improving the bottom end response and power. If I put the bike in sixth gear and slow down to get the revs down to around 3000, I can pull the throttle wide open and the bike hardly responds at all. It just makes a funny gasping asthmatic sorta noise until it gets over about 4500, then the power starts to build and things go back to normal. Is that to be expected with the modifications I've done, or should I be looking to improve things?

Any help would really be appreciated! What's the best place to start?

Cheers,
Owen

August 9th, 2011, 11:16 AM	#162
opc ninjette.org member Name: Owen Location: Canada Join Date: Mar 2011 Motorcycle(s): 2009 Kawasaki Ninja 250R Posts: 121	Hi Guys, I just finished my weekend project of installing a K&N R-0990 air filter and removing the Kleen Air system. The previous owner of the bike had already installed a full Yoshimura exhaust and re-jetted the bike to work with the stock airbox and snorkle. Everything went really well overall, and the entire process was far less daunting than I had anticipated. In fact, I had the airbox out and the carbs fully re-jetted in just a few hours! Here are my current settings which I started with based on someone with the exact same setup as me on the jetting database: YEAR: 2009 INTAKE MODIFICATIONS: Airbox Removed, K&N R-0990, Kleen Air removed. EXHAUST MODIFICATIONS: Yoshimura Stainless Full Exhaust JET KIT OR STOCK?: Jet Kit BRAND OF JET KIT?: Factory Pro Stage 3 Jet Kit MAIN JET: 110 (FP) PILOT JET: 40 (FP) NEEDLE AND CLIP POSITION: 4th clip from top MIXTURE SCREW SETTINGS: 2 turns out for both ELEVATION: 230 feet above sea level I took the time to re-sync the carbs once I was all done, and I adjusted the idle to be about 1500RPM. So the result? Well, it pulls very well from about 6000 to 13000 (noticeably better than it did with just the exhaust and the stock airbox), it's about the same from 4500 to 6000, but the bottom end below about 4500 is now significantly worse than it was before. To get the bike moving quickly off the line I really need to get the engine revs above 4500 and then slip the clutch, where before this wasn't a problem I'm hoping someone here can give me a good place to start in terms of improving the bottom end response and power. If I put the bike in sixth gear and slow down to get the revs down to around 3000, I can pull the throttle wide open and the bike hardly responds at all. It just makes a funny gasping asthmatic sorta noise until it gets over about 4500, then the power starts to build and things go back to normal. Is that to be expected with the modifications I've done, or should I be looking to improve things? Any help would really be appreciated! What's the best place to start? Cheers, Owen