Forums 🚦#HYOCULTURE 😃 General Chat no disrespect ment at all just curious Reply To: no disrespect ment at all just curious

  • Topics: 38
  • Replies: 545
Nov 30, 2017
North UK

I have tried to advise the customer in a few occassions that it will be easier if the bike had clearances done and a deep clutch inspection.  I wanted to know every nook and cranny of the bike including seeing the plugs “with my own eyes” , so i can see any potentioal bottlenecks , and i would have advised some mods to do free.

He has already done 1 carb mod which is altering his slide needle to improve the 4-7k range. (mid range,) that’s well and good.  he would pass a stock GV, just a little bit side to side.

He said it’s had an engine swap and mileage is beyond 10k miles.  It needs clearances doing.  I’ve advised the valves really do matter when it comes to top end performance.

I’ve advised it doesn’t always need to be modifications but it can help sometimes on the “lower end”  so it has a bit more oomph to start off before it runs out of puff at the top gear

He has not told me what the maximum speed was in 5th gear and what rev range it was on, this is with a 520.

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See the screenshot of another customer below ::

This aquila is brand new and he is the only owner and he was my test dummy when helping me choose the correct sprockets during the time i was doing 520 kits for GV125 aquilas. No one was doing 520s for the GV’s years ago after all, the UK isn’t the only country i send chains to.  There is many GV owners on here from spain and other eu countries where the 125cc exist, they seem to ride a lot more than we do! I hope they prove me wrong!

Make of this image below of what you will , my other client has not done any mods , he is an elder man with full bike license rides a pan big cc tourer. He kept the Aquila as a winter hack.  The only mod so far was the chain from this shop.

is his speedo out?  GPS either way is in the 70’s and he is in 4th gear trying to get past a car that was moving too slow on a 70mph road.

This is a dual carriage way, look at the horizon, the road is FLAT (mostly) , there is not much downhill here, if anything, the road inclines up a little bit.


Moving on, i advised that if the clearances get sorted out, she will be happier.

I would not send Roy a 35T sprocket because his engine isnt ready for that,  I can go as low as 30T  (which 30T is unachievable on a 125cc no matter how tuned, 30T has a theotrical max speed of 100 mph, it just won’t happen)

So i customized his gearing to peak at 90 and while that is well and good, it dropped his revs down to about 1,000 rpm less which is intended, as the aquila should scream less.
If i drop the revs too much, it won’t accelerate as good, i had to make a balance, the UK has hills and what not, i do not know which rides he uses.

I would gladly send him a 30T sprocket, he will still moan the bike is not doing 90mph. Will it be the 520’s fault?

No, he hasn’t even maxxed out the chain kit I have sent him yet, which suggests a garage must check his clutch and clearances. He says it’s good.  Korea will say the plates should be a certain thickness and a spring should be this way and that way , from the service manual to suggest if the clutch is “good” or “wanning , but rideable” , mind you the engine is 10k+ old.  It will not be the same as a bike that’s 1,000 miles run in.

Clearances matter. We could spend £400 trying to go fast with mods, but clearances will draw the motor back if its hot and valves close/open too soon, hence clearances to be done.  In the same time, his mechanic will do a COMPRESSION test.
150 psi is awesome (example)  , 120 is OK but at the limit.   150 psi with engine that’s got clearances of 0.10 & 0.20 dead on will be faster in general  (modded or not)

Then henceforward, it’s much easier for the 520 chain set to do justice.

Now then, the GV 520 kits are meant for 2 things  (longevity) as i know aquila riders like to go on long stretches and carry things (panniers!)  . A skinny 428 will wear out much sooner.  I can attest to the fact the hyosung bikes i fix in my own workshop i always change to stronger chains , & 2 clients have had issues that almost caused them an accident.   Is it Korea’s fault ? No , they ship with Oring chains standard, but after that cheaper 428 chains are fitted by garages once the bike comes of age.

Next, KRMotors and any owner that’s bought a brand new aquila will quickly realize the top speed is 70 ish screaming at 13k revs.  Is that healthy? No.
It’s all well and good to drop teeth on a 428, but you loose either top end or acceleration as dropping teeth is more dramatic than a 520  (520 cog teeth are more spaced out, if you want to be scientic,   a 14T 520 will have a circumferance of 10cm and a 428 14T will be 7cm  (this is an example). Rotation size and spinning size mass matters if we are to get scientific, not just the “teeth” count. Gear ratio matters in this case.

He said he has already put a 49T on the 428 which the aquila uses 46 or 48T factory. I was wondering why it won’t hit 70 in the first place. It’s got a 49T, he needed to get lower, which i did on the 520.

Now henceforward he hasn’t maxed out 5th gear at 13k revs to tell us what speed it was on 520. He already knows the bike screams less.

GV = To scream less, and more durability when carrying panniers or going extended tours (hence “Cruiser”) , it’s never going to be a drag racer.  80 is possible because the engine is “designed to do so”

GTR = uses the same GV engine and its factory “82-88mph” =  GT520 kits  (more accel in general, just a little bit, no point me focusing on top end as it already does 80+ factory and ofcourse chain longevity over a skinny 428)

GT= Same engine as the GV = 80+, though its naked so it will have some wind drag slighly.

GTR is the fastest of them all ,  GV was purposefully dropped to 70 by Koreans by means of certain restrictions and weird gearing , so bike is already screaming.

80+ is not impossible ,  you want less revs = happier valves,  you ain’t racing on a drag strip but you want to be able to go 70 in 4th gear and 5th gear now becomes your overdrive.

Whereas on a stock GV you’re already on 5th trying to scream to 70.

I say all this with love please ❤ , but had i known more in depth of the motor , i would have advised a little overhaul job with your mechanics professionally and they will follow the “service” manual. I will then talk to them what the bike needs to meet the client’s desires, i can get super technical with them. Once its in spec, then pimps happen after.

If in any doubt, please ignore this website,  research the top end speed , and watch youtube videos of riders attempting the national speed on a “stock” GV and look at their rev counters.

If in any doubt again, please trust the Korean engineers when they mention what to do when bike has speed issues in troubleshooting section of their service manual.  Also follow what they say to the T including clearances, carb, fueling,  their service manual has a lot of detail and a LOT of checks happen for every part inside the bike including measuring things to see if they are at their limits or not, and beat their limits.

You will be much happier, don’t spend on any more mods, just do what the service manual says every page, she is past 10k after all and so will she show her mood after wards, even if its a little bit better, it’s better than nothing or can leave her alone and enjoy for her what she is & allow the mechanics to sort it themselves , just don’t use cowboy garages or you will waste money again ❤

// Meditation doesn't mean you have to sit still....

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