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hyosung gt250r

Discussion in 'Modifications and Projects' at netrider.net.au started by linx, Jan 5, 2007.

  1. what mods can you do to this nice bike to give it more grunt, ie faster , and higher speed thanks

  2. Dood, its a 250.. Dont waste your money.. You can get a megacycle muffler from PS and thats going to give it a bit of noise which will make it sound faster. Thats about it my friend.. Just learn your craft and then when its time to upgrade, spend your bucks then..
  3. I own a GT250R and what Blue12 said is correct.

    You can make them louder and look nicer but you will waste your money trying to make them go faster. Save your money for the eventual upgrade once you're off your restrictions. :)
  4. ...

    yes but what could u do to it?
  5. Sell it.

    Nah seriously, you can get the can put on, then a performance air filter and maybe rejet the carby.

    Alternatively, constantly ride down big hills and/or ride with tail winds.

    I got one too and its pointless trying to make it go quicker.
  6. upgrade to a honda @125 :p
    seriously.. why do you need to go faster? can you hit the speed limit in the twisties? or did you wanna keep up with the big boys and girls?

    maybe you want the V8's to eat your dust... probably not gonna happen on a 250.
  7. u can put it on a trailer thats attached to a v8 get ur freind to drive the V8 get on the bike and pretend ur going fast

    but u should be able to hit around the 150+ mark doesnt need to go faster

    U can change sproket sizes. But u will lose and/or gain eaither top end speed or acclaration depedning which way u go
  8. Stock standard I got mine up to 169k/hr on the last Full Moon Ride. Still I'm going to get an after-market can and re-jet the carbies, just to tide me over till the upgrade. My mechanic says it should give me 8-10hp extra. Considering it comes with 28HP to begin with, thats about a 30% power increase! Guess I'll have to wait and see. Either way, I am getting it more for the sound, any power increase will be a bonus. After all it is only a 250! :LOL:

    If you want it, go for it! :wink:
  9. There is nothing quite like a little bike that punches above its weight.
    If you wanna go all-out, and rebuild the engine to your own specs, you can have a screamer. As you would be a pioneer in the field of making these babys go fast, it would not be an easy job. Lots of measureing and talking to experts, machining, and waiting for parts to arrive from all over the world.
    If you really want some cheap bang on your little baby, nitrous oxide and lots of it. Gotta be plenty of room to hide bottles on all that bike...
    Need some huge jets in the carby, as the extra oxygen in the nitrous oxide leans the mixture substantially. Not sure of the hyosung carby, but if it has a specific jet for high rpm's should be no probs just to use that.
    Lots of extra power, sfa weight and cost.
    Will not be able to sustain high speed cruising, but there when you want it.
  10. not sure what you mean by what "could" you do to it
    you COULD stick a NOS system on it but hey, it would be a waste of cash!

    best thing to do would be to change your rear sprocket (increase by 3 teeth) so you get greater acceleration. you lose top end speed, but you can pull away from lights a lot better.
  11. Aftermarket exhaust + bigger jets + BMC Airfilter should improve the power around the 7,000RPM -10,000RPM range by up to 5-6HP. This will be noticeable but due to gearing it won't increase your top speed as that occurs around 12-13,000RPM however redline is 10,500+ RPM so your engine is not happy doing 13000RPM.

    You could change gearing for more top speed but I doubt you get much more and you will loose acceleration which you don't have much to sacrifice.

    I'd actually go the opposite and change the rear sprocket for a slightly smaller one as mentioned earlier and loose a little top speed but gain some extra acceleration.

  12. smaller?
    I was always under the impression that you go up at the rear & down at the front for more acceleration & less top speed...
  13. edgeltte you are correct its like a mountain bike you go up the cogs it gets easier to pedal but dont go anywhere in a real hurry

    save your money for the upgrade, you have the bike to learn on not go super quick the bike is not made to do it so why bother???
  14. I don't wanna be the one to rain on your parade, but that is very unlikely! 2-3hp would be my generous estimate.

    You need a larger rear sprocket if you want to improve the acceleration. Personally I would rather put a smaller (1 tooth less) sprocket on the front, as then you can keepp the standard length chain....

    Doing this(downgearing) may not necessarily lose the top speed as I doubt it would be revving to redline as standard in top gear.

    The best way to improve the bikes performance imo would be to excercise more and lose some weight!!
  15. now theres a mod no one has mentioned before :LOL:
  16. Ok, ok, ok... yes I was wrong :oops: a slightly LARGER rear sprocket gives you better acceleration :oops:

    Also note: I was getting up to 425km per tank before the mods and barely getting 350km afterwards.

    At the end of the day the only mod worth doing is the aftermarket muffler. It sounds awesome, safer 'cause it let you be heard and you can always revert your bike back to standard in 10 minutes.

  17. True, but "in theory" you place more strain on the gearbox this way.
  18. hmmm
    If i had this many people bagging my bike, and telling me its not worth improving, i reckon i would have to give it the treatment just so to blow the smirk off some faces through some twisty rd's. The fact of the mater is Hyosung engines have a mild tune out of the factory. Given some basic engineering skills and good advice on cam lobes, engine compression, carby mods ect the engine design could work fairly well for its capacity.
    In a nice light bike, aggressive power delivery from high performing little motors can really get you moving.
    I really hope i meet some of you 250 knockers at the lights when im on either of my 2fiddys.
  19. Nobody was knocking the bike.

    Most replies were sensible enough to point out that it wasn't worth spending over $2k in engine mods....if you think it is worthwhile then go ahead, nobody's stopping you. At the end you'll have gained perhaps a smidgeon more than 5hp, and lost a lot of low rpm power/torque....you may as well have bought a 4 cylinder if you want these traits.

    Mild tune from the factory? I doubt it, although of course there's more power to be found internally (at the expense of reliability!). A bandit 1200 is a good example of a mildly tuned bike...

    Wanna meet at the lights?! I won't bother to get the bike out, I'll be in my car! :LOL:

    Boyakasha!! :LOL:
  20. Fitted the megacycle pipe to my bike and decided to adjust mixture rather than rejet (apparentl'y fairly involved on these bikes). There is a noticable improvement in the mid range (from 6500 - 8500rpm) without compromise in the lower rev range.
    You'll never get awesome performance from a 250 but whether the can is worth it depends on your disposable income.
    I love the note on my bike and quite a few people have mentioned how good it sounds with the new can.
    The improvement will help with overtaking on the highway etc, but don't expect a mind numbing change.
    There's a web site in the USA - these guys race a gt650R and have some interesting observations in the "diary" pages....like the bike performing better on regular unleaded than premium etc., and the shocking performance hit taken from opening up the airbox. Not saying this is going to be the same for the 250 but... food for thought.

    Also, be aware that when changing air filters, you are often sacrificing good filtration for better airflow.

    I read some VERY interesting technical data on tests done using K&N filters and the shocking amount of fine dirt/dust particles they let through. This applied to car filters but nevertheless... will try to dig it up and post it