Forums 🚥 PIT STOP 🔧 Hyosung Technical Help When you know someone messed with it

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    • #6356
      Tom
      Member
      • Topics: 2
      • Replies: 13
      Joined:
      Sep 22, 2021
      @kernow
      Cornwall
      GV125

      I picked up a low milage serviced 4,000 mile GV125.  Stood for 7 years untouched as owner had died.  Well after a week of fiddling she seemed to idle and rev ok but when taken for first ride she was boggy and did not like to accelerate, then decided she did not like idling.

      Time to strip carb properly and take a good gander at what was going on, my initial thinking was more dirt or gunk from standing so long.  I had run cleaner through, cleaned pipes, pump and taken a quick peek at bowl and jets before and they looked clean.

      But on closer inspection with a proper strip down the running issues became quickly apparent.

      First off no rubber bungs over mixture screws and at 3.5 turns not 2.5 front and 2.75 rear.

      Then main jets 95 front and rear, pilot jet 17.5 front and rear.

      Needle has 5 notches not 3. The washer next to it was being used as a shim below the front main jet brass tower.

      The front acorn splits when being removed.

      So got to put this back to normal settings. 🙄

      At least the carb was clean and floats were the correct height. 😆

      Have ordered new acorn, pilot jets and mixture bungs from Marcel, now to track down main jets (N100.604) and possibly needles. But these needles may work with correct jetting so will get jets first.

      Fun, fun, fun.

    • #6378
      Alan McLean
      Member
      • Topics: 8
      • Replies: 60
      Joined:
      Sep 22, 2021
      @macker
      Orihuela Spain
      Aquila GV125

      Hi Tom, when I stripped my carb’s my needle’s also had 5 notches, so maybe they are factory fit, also one of my acorn nuts sheered off, also be careful not to overtighten the new one they are fragile.

    • #6381
      Tom
      Member
      • Topics: 2
      • Replies: 13
      Joined:
      Sep 22, 2021
      @kernow
      Cornwall
      GV125

      Hi Alan, thanks.  I found your post from this time last year and mine where also set to different heights. #4 on front and #5 on back.

      I will set at #3, based on your comment, your post and the needle mod posts. I figured that the extra notches would be where the black lines are in photo below. They seem to match up very well with your photo.

      I am very glad I did not buy any needles.

      Looking at the main jet mod posts my bike had a 3 size increase from 87.5 to 95 so it is no surprise the bike was boggy. Probably why the previous owner apparently stopped using it before he passed away.

      Once again, thank you.

       

    • #6382
      ♠️ MARCEL
      Administrator
      • Topics: 38
      • Replies: 519
      Joined:
      Sep 22, 2021
      @mf448kxn6
      North UK
      GTR

      If you need some jets , just email us. or browse my ebay  @Evocrest is the username , i have listed various jets there too.

      I will try to list more carb parts on here too,  the acorn nuts are very hard and expensive things to stock all the time, so i hope you go easy with the next one lol.

      If the bike has laser plugs (not the junk IX), ngk ht cap, and stronger coils,  using the #5 slot on the needle is OK, as it will help the midrange   (#5 is the one towards the pointy end)

      90 and 92.5 mains is very plenty for the GV125 Aquila plus its naked, so it gets plenty cooling. Unlike GTR’s that run slightly hotter at the rear engine with less air flow passing them.

      Hope you get it sorted , and keep us all posted!

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

    • #6385
      Tom
      Member
      • Topics: 2
      • Replies: 13
      Joined:
      Sep 22, 2021
      @kernow
      Cornwall
      GV125

      Hi Marcel. Thank you, the Acorn, pilot jets and bungs all arrived from you today. Really quick delivery and have arrived before my main jets from MPW.

      Settings I have gone for are all back to standard with 87.5 main jets front and rear, 15 pilot and #3 (middle) notch on needle. Fiqure it is best to get to back to factory settings before I consider modifying things.

      New acorn has gone in without snapping :-P.  Will know if it has all worked in a couple of days.

    • #6387
      Alan McLean
      Member
      • Topics: 8
      • Replies: 60
      Joined:
      Sep 22, 2021
      @macker
      Orihuela Spain
      Aquila GV125

      Hi Tom, using the original factory settings as a starting point is a good idea, if you feel the need to change the needle settings that is something that can be done with the carb’s in situ, as Marcel said a richer needle setting helps the midrange performance, after a little time the colour of the plugs will give you a good indication as to whether you need to richen the fuel/air mix.

      Let us know how you get on.

    • #6407
      Tom
      Member
      • Topics: 2
      • Replies: 13
      Joined:
      Sep 22, 2021
      @kernow
      Cornwall
      GV125

      Well it went according to plan, carb is super clean, original jets sizes, needle on slot 3 and mixtures set to 2.5 front and 2.75 rear. Result is she idles well, repsonsive throttle, revs drop back quickly and pulls through all gears.

      I did replace the carb to mainfold clamps with jubilee clips because the originals are rubbish. The bolt length really restricts where you can place them which just means possible air leak if not tightened enough. Tested all over with carb spray and revs stayed steady so no damage to the super rare and expensive intake manifolds.

      The air box is a sod, as everyone says, but not too much of a nightmare. Take it out and back in from the left and tilt carbs to the left to help align the air funnels.

      To treat the bike, since carbs are super clean, I have ordered a new air filter from Marcel which should be here start of the week.

      Very happy man with a very happy bike. 😀

      Now I will run her for a bit, check plug colour and adjust as needed – as per Alan’s advice.

    • #6411
      Alan McLean
      Member
      • Topics: 8
      • Replies: 60
      Joined:
      Sep 22, 2021
      @macker
      Orihuela Spain
      Aquila GV125

      That’s great news Tom, well done 👏👏

      I also replaced the clip’s on the manifolds as you said the originals are crap, I got the clip’s from Marcel and they worked very well.

      Spot on with the airbox once you’ve had to remove it a couple of times as I did it’s not such an ordeal getting it back on.

      Enjoy and be safe.👍

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