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Discussion Starter #1
hello all...
I have a stock 250 ninja for now but im looking into getting K&N filter pods...
and just doing away with the air box(i hear good and bad things about this) but my Question is about proper jet sizing....my stock main jets are #105...and even at stock it seams 2 be running lean......I know I need 2 go up in jet sizes for the K&N's when i install them but how far? Ive looked into jet kits like dynojet,factory pro and even a kit from a company called sudco who sell ony kits to dealers(and i dont own a buisness)....so thats out of the question...the kits are pretty expensive...between $70.00 and $100.,depends on who has what brand and if its in stock.....it seams cheaper if i just buy the factory jets 1 at a time and dyle it in myself...single jets cost about $4.00 a piece..... I plan on keeping my exhaust stock.... so if anybody has any suggestions,please feal free 2 post(even a guesstimation)
P.S. I dont own a dyno nor a 4 gas analizer.......
I do have a vacuume gauge
thanks
 

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Eddie Lawson is God!
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Repeat after me. "Kawasaki engineers are gearheads. They delight in giving their machines the MAXIMUM AMOUNT of power. If they could give me ONE more horsepower with four yen worth of brass THEY WOULD!!!"

About Dynojet kits, In the REAL WORLD where I live and ride, they offer no benefit. The top end surge they sometimes offer is caused by the hole in the midrange they DO offer.
 

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Discussion Starter #3
Repeat after me. "Kawasaki engineers are gearheads. They delight in giving their machines the MAXIMUM AMOUNT of power. If they could give me ONE more horsepower with four yen worth of brass THEY WOULD!!!"

About Dynojet kits, In the REAL WORLD where I live and ride, they offer no benefit. The top end surge they sometimes offer is caused by the hole in the midrange they DO offer.
In the "Real World" as you put it,If Dynojet has no benefit.. then how do they turn a profit to stay in buisness?? wherever you live and ride ..or so on...

about maximum amount of power....does your local kawasaki shop carry different sized replacement jets...if so "what for??" I mean if it already came with its maximum amount of power...right????
and i wonder what all these different sized jets do besides just take up space...
 

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Discussion Starter #4
come to think about it how does all the other aftermarket companys stay in buisness....must be all that fancy hipe about their maximum performance that those gearheads at kawasaki missed...
thanks for yor yens worth though....
 

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You could spend upwards of 600-800 dollars on after market exhausts, a jet kit, pod filters, and a couple dyno runs to tune everything perfectly and all you'll see is 2-3hp difference on a 250.

Unfortunately ELR is right. Most amateur jet/intake jobs generally don't get the bike running any better than stock, but you only figure this out after you've sunk in lots of $$$.

Your best bet would be changing your sprockets down in front if you want more acceleration, or up in front if you want more top end.

If you're dead set on tinkering I would just try turning out your pilot screws a half turn/ full turn. It will really help you at idle/lower midrange which will give you better "Seat of the pants" acceleration. Otherwise the 250 isnt going to be going much faster.
 

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Eddie Lawson is God!
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Souping up a Ninja 250 is like putting lipstick on a pig. It is a waste of time and effort. YOU can tilt at windmills in an futile effort to make a bike powered by a model airplane motor go faster. I prefer to watch paint dry. Now I'm one of the biggest Ninja 250 fans on this website. A MINT 2005 with 1500 miles and a blown motor is in my project line. But I also know the bike's limitations. The days of a set of carbs giving you 25HP are over.

The white bike in my signature is 100% stock. EVERYTHING has an HD part number.

The green bike has an overbore larger than your motor and dynoed at 164 Horsepower in 1983. The starter makes more power than your bike.
 

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Discussion Starter #7
Souping up a Ninja 250 is like putting lipstick on a pig. It is a waste of time and effort. YOU can tilt at windmills in an futile effort to make a bike powered by a model airplane motor go faster. I prefer to watch paint dry. Now I'm one of the biggest Ninja 250 fans on this website. A MINT 2005 with 1500 miles and a blown motor is in my project line. But I also know the bike's limitations. The days of a set of carbs giving you 25HP are over.

The white bike in my signature is 100% stock. EVERYTHING has an HD part number.

The green bike has an overbore larger than your motor and dynoed at 164 Horsepower in 1983. The starter makes more power than your bike.
The hole pig thing was kind of wierd or desturbing....but let me worry about what i do with my time and money....all i was wanting was possably some input with the info i supplied.....not to be ridiculed....buy the way building a model airplain big enough to accomidate the size of the 250's motor,carbs,fuel cell,radiator(since the engine is liquid cooled and those in radio controlled model airplaines are air cooled.)and starter......NOW that would be the biggest waste of time and money.....
What size motor does your green bike have.....Im sure when they do an over bore its in really small incruments so they dont go so far as to bore into a water jacket...likk .20 over .30 over hell i think .80 over is as far as you can go inless your getting it resleaved..
Also i never said anything about putting on bigger carberators nor wanting to make greater HP......if i wanted 2 do that i would buy a bigger bike!!!!
(THERES NO REPLACEMENT FOR DISPLACEMENT), all i wanted 2 know about was changin jet sizes 2 stop it from running lean.....or maybe just raisind the needle...
(in 1983 i was 7) big deal
you should lend me your starter so it can power my bike some time...meanwhile have fun with the paint.
 

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It's true about it being your time and money. Let me try to clarify your question as to why shops carry so many jets for a particular model. Where I live it is 5500 ft elevation. You or someone else may live at sea level. Let's say a bike has 34 hp, which is what the 250 has or so it is said. I ride a 2007 250 Ninja. My good friend also has a 250 Ninja and claims the bike really dies at 7500 ft elevation. elevation problems can be corrected with jetting and I am sure you know this already. Many folks are under the impression you will gain HP through jetting but the truth is, if you do it right you are only getting the HP you were not getting due to improper jetting. A perfectly jetted 250 will only give you it's 34 HP, poor jetting will fall short of the proclaimed 34 HP. I understand your question as far as wanting to know if anyone could give you some idea as to jet size when switching to pods. It's a fair question. I guess many of the members here have been there already and feel it is of no benefit. I myself have thought of the idea as well but like the fact that my bike runs perfect, no flat spots in the power band and it gives me the mileage I was looking for when I bought it. The engineers at Kawasaki did good and I thank them. Good luck with you pod conversion and as far as the pig with lipstick, that's just a way of saying it is a waste of time. Not a pun toward the little 250.
 

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Eddie Lawson is God!
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In 1982 I was a Kawasaki-Yamaha shop Service Manager. I was also the engine builder for a WERA Endurance Racing team based from the same shop. That 717cc Seca 650 ran its stock CV carbs and airbox. Even at Daytona. What I don't know about motorcycles isn't worth knowing. You come to the master and break his balls when he doesn't give you the answer you wish to hear. My threads are mainly technical. I don't hump anyones leg. I am not social, I already have enough friends with motorcycles.
 

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Discussion Starter #14
Thanks for the link A2rider......but its not the fact about money or time,Regardles of other peoples experiances im still going 2 tinker with it....like i said....im keaping everything stock except the [email protected] RC-1822 pods($60.00) and the price of howmany jets I buy($3.00 a piece)... so its not like ime spending a hole paycheck or anything like that on it....maybe $100.00 tops and if i notice a change....then GREAT....and if not......not a big loss....i enjoy tinkering around + tearing things appart and rebuilding....its what i enjoy.....
GM
 

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You'll never get the pods to run right but if you need to try buy mains that are one two and three sizes bigger and see what you can do.

TO be honesty getting this setup to work right on a small bike is all trial and error. You'll get sick and tired of hauling the bike apart for the 10th time unless you happen to hit the right "combo".

Some 500 riders have changed out the airbox and didn't need to rejet at all. HOLD ON TO ALL YOUR STOCK PARTS AND WRITE DOWN WHAT GOES WHERE. Nothing kills resale value like a hacked up econobike. Its low enough as it is.

Pilots should be okay but a set one or two sizes bigger wont hurt either. The big one is tuning your pilot screws to idle correctly as they're set lean from factory. Pilot screws and a few washers shimming your needles (very thin ones) and you might see a difference. I shimmed the needles on my vulcan and it helped my midrange a little bit with no other mods.

You should really just invest in a good set of decent tires (pirelli sport demons or equivalent, about 200 bucks for the set) and/or upgrading your fork springs (100 bucks new). The bike will handle like its something different altogether.
 

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You can get pods to run right, but since you're not doing any other mods I wouldn't bother - you'll just have more (annoying) intake noise. JimmyD is on the right track with suggesting pilots and needles shims. Most bikes (especiallly as old tech as the EX250) are jetted lean low and midrange for emissions purposes. Sudco or Mikuni has a excellent tuning guide online. Use it to check the leanness/richness of each circuit and adjust from there. You'll probably go up 1 or 2 sizes on the pilots, adjust the air screws, and either shim (#4 washer) or drop the needle clip 1 notch. The mains are probably correct. Be sure to sychronize the carbs - I'd do it after every change since it only takes a few minutes if you have a carb synchronizer.

There is also a 250 Ninja site you could check for advice - Ninja 250 Riders Club :: Profiles
 

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Discussion Starter #18
You'll never get the pods to run right but if you need to try buy mains that are one two and three sizes bigger and see what you can do.

TO be honesty getting this setup to work right on a small bike is all trial and error. You'll get sick and tired of hauling the bike apart for the 10th time unless you happen to hit the right "combo".

Some 500 riders have changed out the airbox and didn't need to rejet at all. HOLD ON TO ALL YOUR STOCK PARTS AND WRITE DOWN WHAT GOES WHERE. Nothing kills resale value like a hacked up econobike. Its low enough as it is.

Pilots should be okay but a set one or two sizes bigger wont hurt either. The big one is tuning your pilot screws to idle correctly as they're set lean from factory. Pilot screws and a few washers shimming your needles (very thin ones) and you might see a difference. I shimmed the needles on my vulcan and it helped my midrange a little bit with no other mods.

You should really just invest in a good set of decent tires (pirelli sport demons or equivalent, about 200 bucks for the set) and/or upgrading your fork springs (100 bucks new). The bike will handle like its something different altogether.
Thanks for the adv. jimmyd
my plan was just 2 start out slowley but i just wasnt sure how many jet size up....I didnt want overkill the first try and i was hoping to get away with buying about 1-4 sizes bigger on the main and hoping to dile it in by the needles with washers and idle mixture screw(wat mm size washer did u use? 2mm 4mm?)and i have been eyeing those pirelli demons...decisions!!!(what should come first and put off till later)
dont worry about the hacking econo bike....if truth be known im verry anal when it comes 2 hanging onto parts....never know when u mite need them or just incase.....things dont workout with a mod and its easier 2 put it back the way it was...
GM
 

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Discussion Starter #19
I appriciate your input midas6t6
maybe with you and jimmys adv. ill get this pretty close from the get go ...if not.....its still winter and snowing plus it is 2 cold 2 ride anyway.....it also make it difficult with all that wind and ice!!!! :) (not including the state road and all there dumping of salt and sand...) ill look for those online guides...i have found a page called 4strokes.com that offers som advice....
ime sure ill get it with trial and error
GM
 

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You can get pods to run right, but since you're not doing any other mods I wouldn't bother
You are right, I just tell most people they won't because it's very unlikely it will happen. Racebikes are generally the only application that pod filters will improve and that is only because other things have been modded to use the extra flow they provide.

That and they are usually dyno tuned to run perfectly. Most shadetree mechanics will only run into it by trial and error.
 
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