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Discussion Starter · #1 ·
I was wondering if anyone on here pieced together your own jet kit? I'd like to get one but don't wanna pay $70+ for it if anyone can recommend the jet sizes I might try that would be great, I've a a set a Yoshimura slip Ons and might do pod filters as well thanx

Droid Bionic
 

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Mostly to make the carb work easier

How much carb work do you plan on doing? In 4 years I have not had my carbs out once. I know once I pull them out, take off the airbox, change the jets and install pods I may have to take them out a number of times to tune them. For what? To get the same result that I would get if, I left the airbox, carbs and stock jets in, shimmed the needles and installed a full exhaust instead?

You have slip ons, right? Why not shim the needles? Why make maintenance harder by putting on pods? I get that putting on pods and installing bigger jets may get you more HP, but realize that HP comes at the top of the rev range. Who rides around @ 11-12k all day or daily commuting?

If you look at most dyno sheets for Ninja 250s you'll notice that the difference, where that a stock bike and a jetted, full exhaust bike make the same HP, is only about 200-500 rpms up til about 11k rpm.

Racers of the Ninja 250 (especially the new gens) can make close to 30 HP with just a full exhaust on a stock bike. About the same that those who remove the airbox and install pods get. I very seriously doubt they pull the carbs on a regular basis to tune them simply because they've gotten about 99% of the max the carb will put out.

Where do you want the most benefit of HP on your bike? Cruising rpms or WOT?

These were just a few questions and some info for your benefit. Good luck in in jetting quest.

Some good info to read.

How Constant Velocity Carburetors Work
http://www.motorcycleproject.com/motorcycle/text/how_cv_carbs_work_v3.swf

Motorcycle Carburetor Theory 101
https://docs.google.com/file/d/0B8nSiz90rrfUSHVGV1JkRUR3eDg/edit?pli=1

Pipe Jetting (A Must Read)
http://www.motorcycleproject.com/motorcycle/text/cows-jetting.html

Carburetor Jet Tech
http://www.motorcycleproject.com/motorcycle/text/jet_tech_v3.swf
 

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Some small things that you can do to help enhance what you already have.

Iridium Spark Plugs-uses less energy, better spark (better spark = better combustion= improved engine performance
K&N Air Filter KA-2586-(drop in)
Synthetic oil
87 Octane ethanol free gas- (if you can get it)
More shims- Depending on the size (thickness of your shims) you may what to add one more. (For example 1 Factory Pro washer is about 0.54mm thick. I have two washers that mic @ 1.53 mm.so you can either move the needle up 1 mm with 2 Factory Pro washers or 1.5 mm with another brand 3 mm washer. 1 washer really doesn't do much.)

 

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Discussion Starter · #8 ·
I've been using synthetic oil, and I do have a new UNI air filter but I'm pretty sure it's a factory replacement bc its the same foam filter. Also shimmed using 2 4mm washers per needle. I'm probably due for new spark plugs ill look into them and the K& N filter as well

Droid Bionic
 
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