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fatass needs corndogs
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Discussion Starter · #1 ·
Bike is light and comfy, cheap...etc. what mods are there to improve performance short of trading up to a 600?
Not opposed to ideas like nitrous or turbo but I dont know what this block can handle. Im changing exhaust and plan on running pods to make it breathe...past that im open to suggestions...or motor swap ideas if yhis frame can handle it
 

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Elbow Grease is Cheap
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lɐʇuǝɯᴉɹǝdx&#4
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Problem with small displacement is that any mods are gonna cost about the same but provide proportionally less return. Small displacement is so cheap you can often pick up a bigger engine (or bigger bike) for less than the cost of effective mods.

Still, if I was set to try such a thing, I might start with this; a fuel injection system made for that bike. http://www.ecotrons.com/Kawasaki_Ninja_250cc_EFI_kit.html

Will make the bike run nicely (no warm up or other carb related issues) and let you jigger things for more power right off the bat (via custom mappings that ignore concerns like economy and pollution), as well solving any fuel / air mix issues that come up with less restrictive pipes / intakes. Pretty much ANY effective power boosting mod is going to require changes to fuel delivery, so it greatly simplifies those concerns if you do decide to go for other mods.

But its $600, which seems like a hell of a lot of money just to get set up for further modifications (and make some monor gains right off the bat)....
 

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fatass needs corndogs
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Discussion Starter · #4 ·
This is what I thought but wanted to ask before I threw the thought away...so now motor swaps to 600 class . Will it work or should I just be content with the wimp?
 

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It's not made to become a power house bike it's made to learn on and sell or keep it to commute but besides that you're not going to make it faster. They can become fun track bikes because they are light weight nibble and that stuff. Some people love them others don't. It's all about what you use it for. I say slap a big sprocket on it and practice stunting on it so when you do get a bigger bike everything will be easier.
 

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fatass needs corndogs
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Discussion Starter · #6 ·
It's not made to become a power house bike it's made to learn on and sell or keep it to commute but besides that you're not going to make it faster. They can become fun track bikes because they are light weight nibble and that stuff. Some people love them others don't. It's all about what you use it for. I say slap a big sprocket on it and practice stunting on it so when you do get a bigger bike everything will be easier.
The problem is that I dont want a lot more, just a little more power. Dont care about speed but dont want to lose any either. With a load its so sluggish im nervous on interstate getting up to speed when im WOT. And im tired of downshifting on long hills. Just really need a bit more torque but not willing to regear to get it.
 

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Why don't you want to regear it? That's by far the cheapest and easiest way to increase performance. -1/+2 on most bikes is about a 10% change, or just -1 is a 5-6% change.

Even a -1 gives a noticeable boost in overall torque without really affecting engine RPM that much. So say 50mph was 5000rpm before, with -1 it will be 52-5300. Whatever your redline top gear speed was before, subtract 5%. So if it was 100, now it's 95. Big deal. You'll also reach 95 a lot faster than you did before which is what matters.
 

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Yea but on the 250 he has it will drop the top speed to 75-80mph which if you're using it on major highways where the speed limit is 70mph its not so cool. Not to mention running it at WOT on the interstate for any period of time is not healthy for those engines
 

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lɐʇuǝɯᴉɹǝdx&#4
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The problem is that I dont want a lot more, just a little more power. Dont care about speed but dont want to lose any either. With a load its so sluggish im nervous on interstate getting up to speed when im WOT. And im tired of downshifting on long hills. Just really need a bit more torque but not willing to regear to get it.
I remember feeling the same way about my gs450, and then even sometimes about my kz650. I suspect that "just a little more power" is never actually enough to make that feeling go away for the kind of person who even bothers looking at a forum like this.
 

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fatass needs corndogs
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Discussion Starter · #10 ·
Yes seb and YZF. Need to be able to run 75 safely for me and the bike. It can now its just those onramps that bother me...if cagers dont see riders they damn sure dont see merging riders and I need the pull to avoid these situations even if they are rare. Changing sprockets will not do it because it drops top speed from 85-90 too low into the 70s. Just need a few more horsepower to get to speed quicker. Not looking for higher top speed or a wheelie beast, just a safe ridable machine
 

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lɐʇuǝɯᴉɹǝdx&#4
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For freeway roll on speed (example - going from 40mph to 70mph) wind resistance is a huge factor. If you can improve the aerodynamics, you'll get up to speed quicker, and have higher top speed.

Honestly can't say for sure how, but its probably easier and cheaper than improving power.
 

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fatass needs corndogs
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Discussion Starter · #12 ·
For freeway roll on speed (example - going from 40mph to 70mph) wind resistance is a huge factor. If you can improve the aerodynamics, you'll get up to speed quicker, and have higher top speed.

Honestly can't say for sure how, but its probably easier and cheaper than improving power.
Well aero simply cant happen. This bike is a purpose build so its got stuff bolted on adding both weight snd aero drag. Gotta be power. 36 hp and 18lbs torque has got to increase. No way stock is as good as it gets. I may dabble with compression increase via shaved head and thin copper gasket. Will be looking at spray also both in nitrous as well as fuel spray to make sure its vaporizing in combustion chamber.
 

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fatass needs corndogs
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Discussion Starter · #13 ·
What about ram air? Cheap and easy enough...im going to change intake anyways because my airbox lid falls off due to previous owners use of dremel tool/angry beaver to apparently change filter.
 

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Elbow Grease is Cheap
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unless you can design a very effective ram air, it won't be effective until 80+ MPH. even if you increase HP by 10%...thats still only 4 HP

honestly, you're chasing a fantasy. There really isn't anything you can do to that engine to "noticeably" increase the horsepower. I say noticeably as some mods may increase throttle response....which your butt dyno will tell you that you've increased HP.

this is a 08-10 250 Ninja system and they got a whopping 6 HP for $550 bucks plus the cost of rejetting and tuning. that's over $100 for each HP
http://www.surfsidemoto.com/store/product/RTZ4330005.html

If you're looking for more HP, save your money and buy a larger displacement bike.
 

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Watch the world burn
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Sell it and buy a bigger bike. You're using the wrong tool for the job.
 

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Anything you can do to lighten it? I took a bunch of extra crap off of mine and it helped a little. :CK187:
Correct me if I'm wrong but couldn't you do a throttle mod? That would at least make it get up to top speed quicker. Right?
 

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Make sure all the mechanical maintenance has been done (valves,ignition, etc). sync the carbs, degree the cams, throw in some jets, drop the heavy exhaust for lighter.
 

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things to remove for weight....

center stand
rear pegs
rear handle
cut down rear fender to bare minimum
whole tail light/plate assembly

mods...
2-1 exhaust....lighter metals a plus.
Shorty muffler...start with something light either way.
bar end mirrors or lighter mirrors
if you keep bodywork maybe replace with something more aerodynamic (if old ex250)
Digital gauge. stock ex250 gauges are bulky as shit.
cnc fuel tank cap
led tail light
around 4lbs of bracketing i think i removed from mine...
took off about a lb of metal moving the lower subframe rail in and up
coolant reservior...get something small

I think thats about the bare minimum for the ex250.

If you need the go when you're on the highway perhaps consider adjusting your powerband to be more high end...pod filters and jet to suit etc.
 
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