Who knows alot about modding the new 08/09 Ninja250's? - Kawasaki Ninja 250R Forum
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post #1 of 16 (permalink) Old 08-08-2009, 06:20 AM Thread Starter
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Who knows alot about modding the new 08/09 Ninja250's?

This is going to be a project bike of mine... I'd love to get at least 60+HP out of this thing or more if I can. Obviously a full exhaust system is going on, getting rejetted, then engine work, then either a turbo or super.. but I'd love some ideas or someone who knows what they're doing to talk me through this. If you know someone who can help me go crazy modifyng a 2008 all-black ninja250, please let me know, b/c I'm gonna do it with good or bad help, but I'd really rather not blow myself up Thanks guys! If youcould recommend another 250 board or forum to go to that might have answers also that'd be great too, thanks again! Also, if you know anyone who knows about electronics, especially eletric motors, please let me know there too... I might have another idea to go along with this one!

Last edited by littlefurious; 08-08-2009 at 06:39 AM.
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post #2 of 16 (permalink) Old 08-10-2009, 01:49 AM
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For that much power gain, I don't think it's possible without major internal works. With that, then you have the reliability issue unless you're strictly using for racing. Either way, I'm not qualified to help. I know the basics.
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post #3 of 16 (permalink) Old 08-10-2009, 09:55 PM
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Get yourself some blue fairings.

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post #4 of 16 (permalink) Old 08-11-2009, 07:51 AM
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(I understand that you are working on a project bike, and it may be a matter of sh(well you know the rest of this word) and giggles, but I have noticed a lot of people wanting to upgrade the 250 (on this forum and others). So I figured that I would finally spread my share of knowledge on this matter. It really won't answer your question totally, but it is a rant, none the less.)

All I have done is a K&N filter (PN# KA-2508). Two brothers does make an exhaust system which will bring you up to about 31HP. Im sure after the K&N Filter and a carb jet kit, you will be pushing 35HP (Disclaimer: I am not a pro, I could be wrong). You could then add a wet shot of NOS and that may get you close to your target.
Is it worth it? You will have spent over a grand on these upgrades.
Instead of modding the bike, I think I am going to get a Ninja ZX6. I love my 250R, as it is my first bike, but I realize that it IS my first bike. It has done its job very well (helping me learn how to ride while avoiding death.)

My plan of action (within the next year).
1. Sell the 250R to a good home - either craigslist or ebay (trading in=bending over)
2. Go to the kawi dealer and sign the papers on a ZX6 (same color as my 250, super atomic bright green)

I understand that modding an existing bike instead of purchasing a bigger bike may be a matter of money, but there are plenty of fairly new, nice bikes on craigslist. Modding the 250 for only performance is a false economy. Not only are you going to trash the resale value of the bike, but it is going to wear out the engine much faster, cause rideability issues, wear out rear tires faster,... well the bottom line is: It is not cost effective to upgrade the 250 vs. buying a bigger bike.

Last edited by Kenny; 08-11-2009 at 08:01 AM.
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post #5 of 16 (permalink) Old 08-11-2009, 05:32 PM Thread Starter
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I've already had 2 ninja250r's... my first bikes. I just got a great deal on an 07 650R as a nice riding bike under 3000 miles and under 4g's. I'm getting a black 08 250r and modding the hell out it... b/c i've always wanted to, I want to learn to mod, it's the ultimate sleeper, it fits me better than any other bike I've ever sat on, and I love it. I've personally seen a turbo ninja250 08 pushing 80HP with no problems and without nitrous. I have free access to tools, a shop, dyno time, fabrication equipment, mechanics( got friends at the army motor pool)... it won't really cost much other than making the turbo, and even that's not bad b/c it'll be homemade. Couple grand and I'll be able to dust a CBR600RR and laugh when his jaw drops. Please help instead of bashing or simply suggesting it's a bad idea. I'm going to do it, if you have knowledge you may as well help as hinder.
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post #6 of 16 (permalink) Old 08-11-2009, 08:08 PM
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oook... il bite
First off, there is no replacement for displacement. Ideally, the engine should be bored or stroked. I have looked and can not find a bore or stroke kit for the ninja 250.

Second, we need to change the "computer" of the engine... the camshafts. I have looked, and cannot find any cams. Perhaps a custom(read: not cheap) grind? An upgraded cam will be a BIG factor in more power. You can do what all of the lawnmower racers(yes, racing lawnmowers is a big event in Virginia) do around here, make your own cam!
These fellers will weld filler to the top of the cam lobes, then file them smooth, to add more lift. It is very effective in Briggs and Stratton engines, but will it hold up to the 13,000 redline of the ninja?

Third, headwork. I am fairly confident that Kawasaki has produced cylinder heads that have outstanding flow characteristics. Having a bubba hit the ports with a die grinder may not be a good idea. Ensuring that they are polished smooth may be a good idea.
Many people believe that polishing is to benifit air flow. Ths is true to an extent. The main benifit of polishing is to eliminate hot spots in the combustion chamber. A hot spot in the combustion chamber will cause preignition. If you polish all of the nookes and crannies out of the combustion chamber, you eliminate hot spots, reduce sources of preignition, and can safely raise the combustion ratio... which brings me on to my next idea.
Perhaps you can shave the cylinder head to increase the compression ratio. You can't go overboard, but a few percentage points wouldn't hurt.

A fuel system upgrade wouldn't be a bad idea either. Maybe someone makes aftermarket carbs. (there may be some badass dirtbike ones that will work) You may even be able to find some kind of fuel injection rig that will work.

As far as the turbo goes... The smallest turbo I can find is made by garrett. Its bottom displacement requirement is .4L (400CCs for dummies). It may fly on the 250 with many mods, but I would avoid it.

If you are really serious about this, I will ride to Silver Spring MD and drink every beer you have.

Or the best idea available... Put a busa engine in it.
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post #7 of 16 (permalink) Old 08-13-2009, 12:47 AM
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Hey everyone. Damn..I didn't see this post before but guess what....I've thought of turbocharging my 250 too! Lol....
Anyway, I agree with a lot of what some ppl here are saying but hey...experimenting on a engine u can get from ebay wouldn't hurt ur bike, but help it. YES...it is possible to turbocharge that engine but you WON'T boost a lot of psi. I personally wouldn't go more then 5 psi...shit, 3 psi would do the trick too! Getting 15 to 20 horse on our little ninja will make it fly...comon, its a light bike! If you won't get much power...oh well but THE SOUND OF A TURBO ON UR 250 WILL BLOW PPLS MINDS! I'm broke, I can't even afford a exhaust system, but once I get a little cash I will try it...not on my ninjas engine but some other used one.
I hope I don't sound like a idiot, but turbo 250R sounds like sex to me!
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post #8 of 16 (permalink) Old 08-13-2009, 07:08 PM Thread Starter
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Well i've heard of an 80HP turbo ninja250, so I'm aiming for 60-80 myself... maybe 90. I'll have access to all the parts, machines, guys who know what they're doing... I have friends who work in a motor pool and they mod bikes for fun, this won't cost near as much as you think. Main prob. is finding the right turbo... most likely i'll just build my own... bigger, better fit, and better boost. And kenny... I hate to tell you man, but I don't drink beer...you're still welcome to drive here and help, I'll buy ya a case of whatever beer you like
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post #9 of 16 (permalink) Old 08-19-2009, 03:07 AM
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it looks like u hv a big plan on d modding this 250(33bhp to a 85-90bhp).....
...all d best dude & dun 4get2 insert photo(if u dun mind at all)

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post #10 of 16 (permalink) Old 06-19-2010, 04:54 AM
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I a sorry to say you will not get those numbers from the 250 engine. It wont happen for a couple reasons. First the new ninja has small valves and very small exhaust ports 27mm.
You cant open the head enough even with bigger valves it wont flow those numbers.

The second problem is the bottom end wont hold up. The engine will handle 50 hp with care and work. But it is a plane bearing motor . The only way to make a small displacement engine produce power is spin it faster. That means making power at a higher RPM . The bearing size will limit the speed the oil can hold the crank off the bearings.and the valve train will start to go after 15000 RPM.

So turbo Charging is first to come to mind.It has been done a couple times .If you can weld and bend pipe and fabricate yourself. Then there is no problem . There are a lot of little thing to figure out .But that is fun. If not it will cost a lot of money.

Nitrous is cheap But has as many hurtles as the turbo dose . And neither of them will make 60 hp. I wish they could .
25 is stock
30 hp is easy 500 bucks and bolt it on.
35 will require major engine work .
40 with major engine work and head porting.
45 Balanced and blueprinted professionally built race motor.
50 Nitrous bomb that will make a couple passes before something happens.
55 hp turbo /supercharged screamer spare no expense.
60 hp Is an over boos that lasted 10 seconds and cracked the case and tossed a rod.

If you want more power than that. Put a Yamaha RZ 350 two stroke engine in the Ninja frame.It has been done and those engine will make 70 hp and last for a while.
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