Jetting my Ninja 250. What a Pain!

[russ69]

Well, I worked slow and easy but man what a pain. The tank has the fuel level sensor connector, main gas line, vacuum line and 3 tank vent lines. What a mess of hoses. Anyway, I just wanted to get rid of some of the off idle leanness. I'm up at 3000 feet so I left the main jet as is. I cut an inch off the snorkel and used the needles from a DynoJet kit. Ahhhhh, much better.....
I'm getting too old for this, I'm pooped. Maybe I'll go on a nice ride tomorrow, that will make up for all the hard work.

 

[orbframe]

thanx, russ

 

[louemc]

Jetting sucks, just Sucks Sucks, Sucky Sucks.

 

[stan23]

I just wanted to get rid of some of the off idle leanness

From my experience, before you changed the main jet, did you drill out the fuel screw cap and adjust there first?

 

[Ironbutt]

Jetting sucks, just Sucks Sucks, Sucky Sucks.

Really??? I like the challenge, it's easy once you get a boiler plate routine going. I can get it close or perfect on the first try now, after 15 years. haha..

I got my EX500 correct after the third go-round but that's cause I didn't have the correct o-rings and the floats were jiggered badly.. The jetting was completely backwards and up-side down.

And who messes with float height and chops o-rings down to size? --The guy who was in there before me.. that's who..

Spot on jetting is soooooo awesome.. It's worth the frustration and learning curve.

--OH.. OP--Do not forget to shim the TOP of the needle. If that needle has any play up-down--the jetting will 'wander' and you'll be wondering what the fuck is up..

 

[/dev/null]

The best thing I did when I rejetted my 250 was scrap the stock airbox in favor of pod filters, so much easier to work on.

 

[nitro-081k]

What a pita!! What a learning lesson...:|

 

[280SQUAGGLER]

I HATE working on 250 carbs with the stock airbox on....Why couldnt Kawi design a easier removal an install ...... i finally have a system but geeezzz i still HATE them

 

[RhythmRider]

Oh cool, nice to see some accomplished Ninja mechanics on board... I'll be hitting you guys up when I need help with my girlfriend's bike

 

[Ironbutt]

I HATE working on 250 carbs with the stock airbox on....Why couldnt Kawi design a easier removal an install ...... i finally have a system but geeezzz i still HATE them

Get out? really? A small pry bar goes a long way to pop the carbs out of the boots without pulling your back out.

They go back in at an angle..down-- Floats up --engine side first.. they slide on like your putting on a shoe.

They come out at an angle--engine side up first-opposite of the way they go in.

Usually the main jets on these bikes are good.. just change the needle and replace the little pilot fuel screw o-ring. 2.5 turns out. leave it alone..

The needle on the EX carbs are on the first clip from the top w/132 mains.. the mains are 1 step too rich<for this 50-60deg weather> but it keeps the motor running cool.. it's pretty beat up and burns a lot of oil as it is. so I'll settle for on the rich side and keep the motor together.

 

[llenta]

I remember having to go through all that with my old 250. I think it took me about 5 months of constant adjusting to get it just right. But it was night and day difference from the stock set-up. Honestly, the only reason I kept doing it was because I swapped out the philips screws that came on the carbs, with hex screws. That way I could get a good bite on them and remove them (without stripping them) without removing anything from the bike. Don't need to remove the gas tank or the air box or nothing. Just reach in from the side, loosen everything out, and pull them out from the side.

 

[fast4d]

PODS.....they make life SO much easier....

 

[Ghost8475]

This is probably going to sound really ignorant of me, but does rejetting your bike really help it, and what does rejetting do? My bike is at 20k miles, and is there a point to even do it past a certain point?

 

[Ironbutt]

PODS.....they make life SO much easier....

Except for jetting..

 

[llenta]

This is probably going to sound really ignorant of me, but does rejetting your bike really help it, and what does rejetting do? My bike is at 20k miles, and is there a point to even do it past a certain point?

Jetting will make your bike run better. Your bike more then likely is running really lean. If you have your bike jetted properly, it will have much better throttle response, and pull harder all the way to red line. It doesn't matter how many miles your bike has.

 

[Ghost8475]

Jetting will make your bike run better. Your bike more then likely is running really lean. If you have your bike jetted properly, it will have much better throttle response, and pull harder all the way to red line. It doesn't matter how many miles your bike has.

So then whats the negative of it? Does it make your bikes engine go kaput sooner, or?

 

[tuxumino]

what I'm told by old 250 racers is: jet for top end, putting pod filters on the carbs will lean out the bike and you'll lose some bottom end, jetting is necessary if you go to pod filters.
I agree that the airbox on the ninjette is bloody vile, and a pain to get in and out of the bike.

 

[Cycle61]

I HATE working on 250 carbs with the stock airbox on....Why couldnt Kawi design a easier removal an install ...... i finally have a system but geeezzz i still HATE them

what I'm told by old 250 racers is: jet for top end, putting pod filters on the carbs will lean out the bike and you'll lose some bottom end, jetting is necessary if you go to pod filters.
I agree that the airbox on the ninjette is bloody vile, and a pain to get in and out of the bike.

Yep.

FUCK that airbox.

I'd scrap mine in a hot second if I wasn't running production.

 

[llenta]

only down fall to jetting (other then the time it takes) is your bike will probably use more gas. this is assuming you adjusted your carbs in that direction. i went from a bone stock '08 getting ~65 mpg, to a full Area P pipe complete rejet getting ~55mpg (less at the track). but of course every bike is different and everybody riding style is different.

 

[Sharky]

PODS.....they make life SO much easier....

If you can get them jetted right.

As a kid I ripped the airbox out of my GPz 305 (big older brother to Le Femme Ex250) and installed pods. I didn't know crap and found out rather quickly that the carbs had to be rejetted. Well in the stoneage those kits weren't as available as today. I fiddled around with needle height and basically called it quits when I ran out of money. A little electrical tape to restrict air flow and I was back in business. Lot to be said to working out a flatspot by adding or removing strips of tape.
Being broke improved my MacGuyver skills. just a lot of work for a questionable power gain.