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North UK

I saw the youtube clip, hmmm i can try break this down for ya , follow me, i think i am on to something but will need you to also verify next time you have your hands on it.

  • Spray  the airbox rubbers and intake rubbers = see if revs change or engine grumbles or screams = air leak.
  • Rev up to 5000 rpm then let go, do you see any kind of smoke, do you smell any oil stench on the exhaust ? = too much engine oil , or concern for oil in engine (replace it, if the bike ever had fuel leak out of the carbs when it was OFF)
  • I see you have a full tank, buy WYNNS FORMULA GOLD PETROL (this bottle only) pour all in the tank, ride a bit and let us know if the bike starts to behave a little better as the fuel bars drop low.
    I trust the carbs are clean already but the WYNNS bottle might also make its way through the fuel lines, spark plugs , pistons ,to get some gunk off and take away some carbon (it will try!)

Plug Analysis

  • Front center cone = main jet is OK, full throttle seems OK,   but idling a bit rich due to dark black sooty ring but…..is the black ring oily or ashy-dusty ? – The plug’s threaded body looks dark at the base and almost silver rest of the way towards its white insulator,  it means front cylinder isn’t overheating like crazy  (thanks to winter and the nakedness of the GV!)
  • Rear Center Cone + Rear RING = OK.  Nothing to add here, it’s good! – This is the “aim” or sweet spot if you will.
  • However, rear body of the plug suggests its a bit hotter than the front (threads are darker = hotter cylinder head but …. not concerning yet)

Throttle dipping / climbing means either these but we will narrow it down as we progress on servicing her…

  • Mixtures  , try to ride at 2.5 full turns out each cylinder and see how it generally rides. This will be our base as going beyond 3.5 turns is totally pointless , it will have less effect once you in full throttle (main jets and “slides” take over) so full throttle issues should be jets and slides (sticky?) …)  or floats or fuel pump wanning or tap wanning , or the fuel parts have debris hence Wynns Formula in petrol to collect em and engine to burn them off out of the exhaust
  • Pilot Jet clogged again  (revs flactuate) is a sign its “hunting” for fuel to prevent the bike stalling abruptly
  • Starting = Permanent Jet + Pilot Jet = If you get access to air compressor , blow them hard
  • Fuel Levels = float heights , pilots “barely” reach the fuel but i think you know how to adjust them to a sweet spot by now 🙂 or i understand you’re experimenting with fatter aftermarket floats vs OEM ones but they still have max resting height of 7mm-8mm max .  7mm is the OEM sweet spot, i understand float needles and what not can affect the height a little bit , too much here or there can overflow fuel out of the carb so adjust and check accordingly.
  • Richness = revs up, then dips below 1500  (see what i said prior to this sentence)
  • Needle of the Slide = If it has 5 steps to go down to the pointy tip, try step #5 , if its worse, go up to step 3 which is its default middle setting but never go beyond step 2 and 1 as those will lean out the bike.   5 step or 3 step needles Korea uses are always at the middle setting from factory.   Going to the middle lets you see if full throttle makes it hit 70mph or not.  More speed more fuel or too much fuel can bog it if rest of the bike isn’t optimized   (air vs spark (all electrics from coils, plugs etc,) vs fuel  (carb, tap, pump)


Full service is not a bad call! – You want to get to it before it gets too cold and Xmas is around the corner where families rob our time until new years lol

I hope this reply made any sense but if at one point i confused you, just let me know , ill explain better next time

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