Mods thread: Hyosung GT250R

[Radar]

http://www.richardhyosunggvgt.com/co...25250650rs.htm

Hey deano and enzo - I want to thank you for this link:
http://www.richardhyosunggvgt.com

I emailed Richard (in Korea) about getting a (rear) shock absorber and he emailed right back - that guy is FAST, like one minute to reply. He let me know when the deadline was for making the Friday delivery and I managed to get in and the shock - plus two other small bits - was sent and could arrive as early as Monday, possibly Tues or Wed. Wow, that is QUICK service - we need more internet businesses like Richard's. Oh and yeah, his prices, including shipping, are really good!

BTW, I thought I needed a new CDI (cannot remove a wire on my model cuz there is only ONE wire in the brown connector) so took it to our local Hyo mechanic so he could test drive my bike. The good news is he says there is no flat spot and it runs really well, but the bad news is that it needs a new rear shock and the price the shop gave me was waaaaay too high.

[deanohit]

Glad to help man.

[Radar]

Hey guys, whats the deal on REJETTING carbs? Does it really increase performance, and if so, it must be be at the expense of fuel consumption, right? How much does rejetting cost? Is rejetting only done when a different exhaust system - muffler - is installed?

[The Pastor]

for best gains you rejet when you change something, like air intake and exhaust flow. more air goes in, more fuel can fit. etc etc.

[rickjames]

The main reason to read this thread is for info on modding your Hyosung CDI unit for better response / eliminating the famous 3'rd gear flatspot..**

This thread is all about my sexy GT250R, or at least it will be - I'm starting to customise it now that I've hit 8,000k without the slightest problem. So here's a list of what I've done so far and what needs doing. I'll update as I go.

What I want is any advice other bikers, particularly any Hyobag owners might have on these:

I thought these would come fairly wanked up already after reading the marketing speel?

"Ready to race, ready to ride. The GT250R is a full size race tuned bike with looks to match. Fully equipped with rollerized V-Twin high output DOHC 8 valve engine, race tuned suspension including inverted forks and gas charged shock absorber, huge brakes, stunning aerodynamics, complimented by digital instruments and adjustable ride position. Whether you're starting a race career, riding for fun or just getting around, the GT250R is ready to take you where ever you want to go.
Dual lens headlamp and aerodynamic fairing are stylish and functional. A tinted windscreen is available as an optional extra. Race position handlebars and adjustable footrest positions give the rider flexibility to tailor the ride position to rider preference. "

http://www.trademe.co.nz/Trade-Me-Mo...772858.htm?p=1

[EnzoYug]

Marketing speel is for chumps.

It's the price tag, and the word of other bikers that'll truly tell you what you need to know.

[Iain]

Hey guys, whats the deal on REJETTING carbs? Does it really increase performance, and if so, it must be be at the expense of fuel consumption, right? How much does rejetting cost? Is rejetting only done when a different exhaust system - muffler - is installed?

Ive just put a Screaming Demon exhaust on and will talk to the guys at JFK about dyno and rejetting as well as whatever airbox modification they need to make.

I spoke to someone who the the same thing done at JFK and he said the before and after dyno showed an increase of 10HP. Not sure if it was 6 and he just rounded to 10 But Ill let you know how it goes.

Iain

[Radar]

Just found this (which could help doing mods):

The workshop manual:
http://www.hyosungcomet.com/archivos/manual_250.rar

OK, yes I know its for a Comet, not a GTR, but the mechanics are basically the same.

Anyone know where to download other Hyo workshop manuals?

[Radar]

Hey deano and enzo - I want to thank you for this link:
http://www.richardhyosunggvgt.com

I emailed Richard (in Korea) about getting a (rear) shock absorber and he emailed right back - that guy is FAST, like one minute to reply. He let me know when the deadline was for making the Friday delivery and I managed to get in and the shock - plus two other small bits - was sent and could arrive as early as Monday, possibly Tues or Wed. Wow, that is QUICK service - we need more internet businesses like Richard's. Oh and yeah, his prices, including shipping, are really good!

The shock just arrived - ORDERED Friday afternoon, DELIVERED Monday - amazingly quick service from Korea to Masterton. I am impressed.

So if you guys want to do mods, I recommend that you order from Richard in Korea.

Also came with the shocks - two sets of over-handlebar-grips hand warmers - one set for my friend. Very good quality and only $27 NZD (without shipping since they had a free ride with the shock absorber).

[325rocket]

I spoke to someone who the the same thing done at JFK and he said the before and after dyno showed an increase of 10HP. Not sure if it was 6 and he just rounded to 10 But Ill let you know how it goes.

Iain

i think youll find its 10 DB not HP

[EnzoYug]

i think youll find its 10 DB not HP

Ha, alot more than 10DB.... But yeah, you can take they Hyo's quite close to 40HP if you put the work in. A lot more than just pipe and carbs tho...

[Rev DJ]

Wow - did the CDI mod last night just before the Wednesday night Wellington run - Woa what a difference. Followed the description on this thread - took a couple of minutes and then

I cant understand why this mod isnt done by the bike shop before the Hyo's are sold? Good pick-up and power band - bike is performing as I had hoped now

Cheers DJ

[CookMySock]

I cant understand why this mod isnt done by the bike shop before the Hyo's are sold

I read it was an emissions thing. Dunno where sry.

DB

[CookMySock]

Ok time to update.. It took me about 4 hours to do but it's done.

cool to read about your mods. Have you noticed any difference in the fuel economy yet ?

thanks,
Steve

[Iain]

Wow - did the CDI mod last night just before the Wednesday night Wellington run - Woa what a difference. Followed the description on this thread - took a couple of minutes and then

I cant understand why this mod isnt done by the bike shop before the Hyo's are sold? Good pick-up and power band - bike is performing as I had hoped now

Cheers DJ

I does make a difference doesnt it. Much smoother changing gears as well. I was told that it was an emission thing. It retards the timing through the rev range to reduce emissions... Unfortunately it seems to cause a flat spot between 5-6k rpm. Since we dont have vehicle emission testing like in California and Canada we get away with eliminating this 'feature'.

Works a treat though eh!!

Iain