GPX250 - Two Brothers Exhaust

[Kodez]

Hey dudes, just put this on the lil' gpx today:

So I figured i'd write down my thoughts. Obviously their's no change in power but i've noticed much smoother and quicker acceleration, the main benefit with the addition of the 2Bros pipes was to the handling of the bike believe it or not. The weight saving must be about 6-7kg's, I could not believe the weight difference! (i've got scales so i'll grab the exact figures next week when i paint the headers). Without that excess weight on the rear end the bike is much more stable around corners, not so much feedback or mid corner bouncing lol (yeah the GPX has a ridiculously shithouse rear shock but hey, it's improved marginally). Last but not least the sound, of course it sounds way better than stock! At idle it's a bit average, kind of like a fart at anything lower than 1300-1400rpm but on noise I reckon it sounds mint for a two fifty, has a nice grunty tone to it, like a itny v-twin almost. Loud enough to grab the attention of passers by now, their is a 'powertip' available to insert into the end of the exhaust to quieten it down but I like loud stuff
So overall I was impressed with the Two Brothers Exhaust, its made the bike more enjoyable to ride and is hardly a necessary addition to a learner bike but if you got spare cash i'd recomend this system.
Kodez.
P.S i've not yet had the carby's tuned to suit the exhaust

[bobinatcat]

Single sided exhaust for a gpx?

[Kodez]

Dual, the other slipon is wrapped in the white plastic stuff. Single sided systems are available for them, I considered purchasing a 2 into 1 header and slipon for it but this worked out at the same price.

[Gimpy]

So you *had* a vtr according to your avatar?

How much it cost you in the end + time/effort? Might be good to convince a few others. Seen soo many "mice in spinning wheel" sounding 250's about the place.

[Kodez]

Lol got a bit excited with the vtr, was a definite purchase until i went to pick it up and i noticed the HUGE pool of oil under it.
Cost me $400 AU inclusive of postage (fleabay) and about 10 mins to rip the stock pipes off and install the twobros. Going to cost a bit more for a carb' tune aswell.

[bobinatcat]

Ah yeah, I see it now

[kuba]

For about $100 to 150 you can get a shock from one of the new 250r ninjas, which was the best and cheapest handling mod i did/can do to the GPX, seriously look into it (my only regrets was i put it on 2 months before i sold the damn thing).

[Kodez]

For about $100 to 150 you can get a shock from one of the new 250r ninjas, which was the best and cheapest handling mod i did/can do to the GPX, seriously look into it (my only regrets was i put it on 2 months before i sold the damn thing).

direct fit?

[K1GxR]

^^still an unproven myth

kawasaki dealers have no idea about them and kawasaki mechanics cannot confirm they will fit, even though i was told several times they have different swing arms. i only read about this on PSB.

also a rear shock for a 09 / 10 ninja is over 800 bucks new and i can never find one 2nd hand as they bikes are so new and hardly wrecked, and when they are wrecked they are spectacularly damaged the rear shock is never salvagable.

[kuba]

Yep can whole heartily say 100% direct fit (mine was an 05 model but all gpx's had the same rear shock.
Ninja250 Howto - Ninja250Wiki has good info on the gpx's which is where this idea came from.
When I looked I got mine from over east wrecker delivered to my door for just under $150 (shock had apparently 15,000 kms on it), at the time there were plenty in the US on ebay but the $ wasnt so strong so was nearly $200 to the door. If you want to chase one use Car Spare Parts, Auto Parts, Motorcycle Parts, Truck Parts, 4x4 Parts - Australia's #1 spare parts locator | Find, buy & sell new & used parts online or ebay, you only need the shock nothing else (some dealers will charge bullshit amounts also).

Search using ninja250r or ex250j, the shocks are easy to spot as they got the adjustable thing on em, also other older bike model listed on ninja250.org but they were harder to find and usually well used. Doesnt seem to be as many as when i looked a year ago but im tired and not really fussed good luck (Its seriously one of the best things you can do to the GPX)

some current ebay examples
2008 KAWASAKI EX250J EX250 NINJA 250R SHOCK SUSPENSION | eBay
Kawasaki Ninja250 (EX250J) 2009 Rear Shock - Fits 08-09 | eBay

[Kiz.B]

Yep can whole heartily say 100% direct fit (mine was an 05 model but all gpx's had the same rear shock.)

So if the shocks are the same, your suggesting the rear swing arm would be near similar, yes? I got a 2000 GPX, and am a big fella and since buying my bike have been hunting to find something to get me rear spring rate up. This seems like a mint idea!

[Kodez]

If a cheapy pops up on fleabay i'll grab it and see how it goes.

[Kiz.B]

How do them exhausts sound on your GPX? I've thought about throwing an exhaust on, but $$$ is limited. Have you looked into the jetting yet?

[reNEGaDe88]

How do them exhausts sound on your GPX? I've thought about throwing an exhaust on, but $$$ is limited. Have you looked into the jetting yet?

I have a '07 GPX with two bro's pipes. They sound really good, bit loud but. Nice soft puff when it's idling though, to not to piss neighbors of. Feels a bit faster and smoother. DW about jetting $$$ that won't have much effect.

[Kiz.B]

DW about jetting $$$ that won't have much effect.

Damn... Was hoping to get the torque curve shifted down a bit. Guess I'll bang that 08 Ninja 250R and be done with her for the next 10 months.

[Kodez]

Damn... Was hoping to get the torque curve shifted down a bit. Guess I'll bang that 08 Ninja 250R and be done with her for the next 10 months.

It makes the acceleration much smoother but theirs no 'performance' improvements at all.

[Kodez]

I have a '07 GPX with two bro's pipes. They sound really good, bit loud but. Nice soft puff when it's idling though, to not to piss neighbors of. Feels a bit faster and smoother. DW about jetting $$$ that won't have much effect.

Wasn't jetting I was going to get done it was just a 'service' of the carby seeing as my bikes from 1994 i'm pretty sure its not balanced and the carby internals are probably dirty as all hell, everything else has been so far :/
As far as the sound goes have you looked into the powertips yet?

EDIT: Apparently is easy to balance the carbs and clean them so I might have a go myself seeing as this is no longer my daily. Money's tight though now seeing as the Calais is absorbing all my funds....

[NMBRPL8]

Yes they are easy to do, but if well used then the older girls can be a bit worn and sloppy - wow that could sound wrong huh? Take a plug reading too, if she is running a tad lean or you want to open the airflow up a bit while your in there, raise your needles up a little, it will give u that lil extra fuel and should be pretty close for just an exhaust swap and maybe some better breathing. Adding a better exhaust will lean it off a bit, but probably not a huge difference on your gpx.

[Kiz.B]

Yep can whole heartily say 100% direct fit (mine was an 05 model but all gpx's had the same rear shock.
Ninja250 Howto - Ninja250Wiki has good info on the gpx's which is where this idea came from.
When I looked I got mine from over east wrecker delivered to my door for just under $150 (shock had apparently 15,000 kms on it), at the time there were plenty in the US on ebay but the $ wasnt so strong so was nearly $200 to the door. If you want to chase one use Car Spare Parts, Auto Parts, Motorcycle Parts, Truck Parts, 4x4 Parts - Australia's #1 spare parts locator | Find, buy & sell new & used parts online or ebay, you only need the shock nothing else (some dealers will charge bullshit amounts also).

Search using ninja250r or ex250j, the shocks are easy to spot as they got the adjustable thing on em, also other older bike model listed on ninja250.org but they were harder to find and usually well used. Doesnt seem to be as many as when i looked a year ago but im tired and not really fussed good luck (Its seriously one of the best things you can do to the GPX)

some current ebay examples
2008 KAWASAKI EX250J EX250 NINJA 250R SHOCK SUSPENSION | eBay
Kawasaki Ninja250 (EX250J) 2009 Rear Shock - Fits 08-09 | eBay

I brought the first linked eBay item and have fitted it. kuba is on the ball - my GPX is unbelievable! I'm a big fella and its rock solid and the speed out of corners... Seriously worth the effort.

^^still an unproven myth

I get the scepticism, I researched a bit before I made the purchase.

also a rear shock for a 09 / 10 ninja is over 800 bucks new and i can never find one 2nd hand as they bikes are so new and hardly wrecked, and when they are wrecked they are spectacularly damaged the rear shock is never salvagable.

I got the first one of kuba's eBay ad's he found and posted up here. $150 delivered to my door ex-USA. 2008 Ninja shockie in PRISTINE condition. Even the paint around the bolt holes was barely scuffed! And there is absolutely no signs of repainting - the Kawasaki warranty sticker is intact even! Seriously get a look in if your wanting some performance outta the little GPX. It really does go like a shower of s*** now.

[kuba]

Glad to see I could help someone! Its definitely worth it.