Thursday, March 26, 2009

PERFORMANCE TIPS FOR GY6 POWERED ASIAN ATV AND SCOOTERS

THERE HAVE BEEN ALOT OF IMPROVMENTS TO ASIAN OR CHINESE IMPORT ATV's AND SCOOTERS, ALTHOUGH THERE IS STILL A DARK CLOUD OVERHEAD DUE TO BUILD QUALITY, THERE HAVE BEEN SOME UPGRADES TO QUALITY OVER THE LAST FEW YEARS AND THE PRODUCTS HAVE COME ALONG WAY. AS COMPAIRED TO THE BIG FOUR, HONDA, KAWASAKI,YAMAHA,AND SUZUKI THE QUALITY IS NOT THE SAME, BUT ALSO NIETHER IS THE PRICE, WITH THAT BEING SAID YOU HAVE TO KEEP IN MIND THESE LITTLE CHINESE IMPORTS REQUIRE A LITTLE MORE MAINTENENCE.

THE ENGINES ARE A COPY OF HONDA'S 50cc TO 150cc GY6 DERIVED DESIGN AND OFFER ALOT OF PERFORMACE IN A LITTLE COMPACT PACKAGE. THERE ARE A TON OF PERFOMANCE PARTS AVAILAIBLE FOR THEM, AND DONE IN THE RIGHT COMBINATION THEY CAN BECOME ABSOLUTE SCREAMERS WITH MUCH IMPROVED POWER AND TORQUE.

MY SON HAS A 150cc SUNL SPORT ATV,ELE START, AUTO TRANS WHICH IS BASICALLY THE SAME SET UP AS THE SCOOTERS,SO THE PERFORMANCE MODS WE HAVE DONE WILL WORK THE SAME ON THE SCOOTERS AS WELL THE ONLY DIFFERENCE BEING A SLIGHT TUNING CHANGE IN CLUTCH AND VARIATOR. I WILL COVER THAT LATER. THE 150cc HE HAS IN STOCK FORM WAS FAIR AT BEST AS FAR AS POWER WENT, BUT HE IS 11yrs OLD AND ABOUR 65LBS SOAKING WET...LOL. WE RIDE OUT IN THE SAND DUNES IN GLAMIS CALIF. SO YOU NEED SOME PRETTY GOOD POWER TO TURN THE PADDLE TIRES IN THE SAND, HIS ATV IS EQUIPPED WITH SAND GEAR 18" TALL PADDLES. I KNEW WE COULD TUNE IT FOR BETTER PERFORMANCE AND WE STARTED SMALL AT FIRST. I WILL GO IN ORDER OF WHAT WAS DONE SO AS TO KEEP IT AT SEVERAL STAGES FOR PERFORMACE AND ANYONE CAN ADAPT THIS TO THERE OWN ATV/SCOOTER
STAGE 1 CLUTCH TUNING
THIS IS KEY FOR ANY ATV/SCOOTER, THE CLUTCHES/VARIATOR SET UP. THERE KNOWN AS CVT TRANSMISSIONS AND FROM THE FACTORY THERE PRETTY MUCH ALL WRONG AS FAR AS WEIGHTS AND SPRINGS ARE CONCERNED, TO SOMEBODY THAT HAS NEVER TUNED ONE OR RODE ONE TUNED RIGHT THERE WOULD FEEL NORMAL, MYSELF COMING FROM A BACKGROUND OF ALWAYS RACING SOMETHING SINCE I WAS A KID (go karts,cars,boats,atv's,snowmobiles ect) I KNEW THERE WAS ALOT OF ROOM FOR IMPROVEMENT. WE REPLACED THE VARIATOR WITH A KOSO 115mm TEFLON COATED ONE, INSTALLED DR. PULLY 10 GRAM SLIDE WIEGHTS SWITCHED THE BELT TO A KELVAR RENFORCED DRIVE BELT, ON THE DRIVE CLUTCH WE REPLACED IT WITH A PRODIGY CLUTCH, INSTALLED 1500rpm CLUTCH SPRINGS, AND A 1500rpm MAIN SPRING, THE NEW CLUTCH/VARIATOR SET UP WAS AMAZING, IT PICKED UP APPROX 9MPH, BETTER HOLESHOT POWER AND THE BACKSHIFT WHEN YOU GET ON AND OFF THE THROTTLE WAS NIGHT AND DAY. IF YOU ONLY DID THIS UPGRADE ALONE IT WOULD BE THE BEST THING YOU COULD DO.
STAGE 2 EXHAUST AND INTAKE WITH STAGE 1
THE BETTER FLOW IN AND OUT CREATES POWER, THE STOCK 24mm CARBS ARE JETTED SO LEAN FOR ECONOMY AND EMISSIONS JUST STEPPING UP THE MAIN JET 2 SIZES WAKES THE MOTOR UP I INTIALLY JUST REJETTED THE ORIG CARB BUT THEN REMOVED THE STOCK AIRBOX AND INTALLED A AIR INTAKE AND UNI FREE FLOW FILTER, WHEN THIS SET UP IS DONE YOU NEED TO REALLY STEP UP THE JETTING USED A .40 PILOT JET AND 130 MAIN JET, BIG IMPROVEMENT ON POWER AND WITH THE CLUTCH DONE ITS NOW STARTING TO REALLY COME TOGETHER AS A POWER PACKAGE. THE STOCK MUFFLER WAS REMOVED AND I PUT A FREE FLOWING SILENCER ON THE EXHAUST WE USED ONE FROM TOOMY RACING, IT ACTUALLY IS A SILENCER FROM A YAMAHA BANSHEE, WE MADE AN ADAPTER WITH A 3" PIECE OF PIPE AND IT CLAMPED RIGHT ON,WE ALSO HAD TO MAKE A NEW HANG BRACKET FOR IT, VERY SIMPLE JOB TO DO. WANTING MORE POWER BUT BEING LIMITED TO THE 24mm. A CARB A CHANGE TO A 30mm IS THE NEXT STEP THIS IS A EASY ENOUGH CHANGE OVER WITH MINOR MODS TO THROTTLE CABLE AND SOME REROUTING OF VACUUM LINES, YOU WILL NEED A NEW INTAKE MANIFOLD 30mm SIZE, AGAIN ITS SIMPLE JUST MARK ALL THE OLD LINES AND SUCH FROM THE OLD CARB. JETTING HERE IS CAN BE FINE TUNED DEPENDING ON ALTITUDE WE RIDE AT 0 TO 700 FT MOST THE TIME SO WE WENT WITH A 42 PILOT JET AND A 132 MAIN JET, WORKS FINE, IDLES SMOOTH AND CARB IS RESPONSIVE.
STAGE 3 IGNITION SYSTEM WITH STAGES 1 AND 2

THE STOCK IGNITIONS SYSTEM WHICH CONSIST'S OF A CDI BOX AND COIL IS OK FOR A STOCK MACHINE, BUT WHEN YOU START DOING SOME MODS WITH FUEL AND AIR IT REQUIRES SOME ENHANCEMENTS, THERES A AFTERMARKET "BLUE" CDI BOX WHICH HAS A RECURVED TIMING CURVE AND NO REV LIMITER, THESE GY6 ENGINES TURN ABOUT 6000RPM WIDE OPEN IN STOCK FORM, YOU CAN EASILY TURN THEM UP TO 8000RPM WITH NO ADVERSE EFFECTS, THAT WHERE THE HI PERFORMANCE CDI's COME IN, IF YOUR RIGHT ON THE CLUTCH TUNING AS OUTLINED EARLIER YOU WILL BE IN THAT POWER BAND WHERE THE MOTOR WILL PERFORM BETTER, WHEN YOU HAVE ADDED FUEL AND AIR AS WITH A LARGER 30MM CARB, THE UPGRADED CDI IS NEED, ALSO YOU WILL WANT TO UPGRADE THE COIL WITH THE PERFORMANCE "ORANGE ONE THATS AVAILIBLE, THOSE TWO UPGRADES TIE ALL THE STAGES TOGETHER.
BASICALLY ALL THE UPGRADES HERE CAN BE DONE ON ANY GY6 ENGINE SCOOTER,ATV OR BUGGY, THE ONLY DIFFERENCE BEING THE VARIATOR TUNING AND CLUTCH DUE TO THE WEIGHT OF THE VEHICLE AND RIDING CONDITIONS. THESE CHINESE MACHINES TO REQUIRE A BIT MORE MAINTINANCE AS FAR CHECKING FOR LOOSE HARDWARE BECAUSE OF VIBRATION, THE BIGGEST COMPLAINT OWNERS OF THESE HAVE IS THEY DONT MAINTAIN THEM SOMETHING VIBRATES LOOSE AND THE VEHICLE STOPS RUNNING, THEY THEN CALL IT A PILE OF JUNK AND BAD MOUTH ALL OF THEM, I STAY ON TOP OF MY MAINTENANCE AND NEVER HAVE A PROBLEM AT ALL, BUT THATS ME, MOST PEOPLE ARE NOVICES WITH THESE ITEMS AND DO NOT KNOW ANY BETTER, NOT TO PUT ANYONE DOWN HERE, ITS JUST THE WAY IT IS.

SUSPENSION UPGRADES:


FOR THE ATV OWNERS THERES NOT MUCH YOU CAN DO WITH OUT GETTING CREATIVE AND KNOWING A LITTLE ABOUT SUSPENSION TUNING, BALANCE AND HOW IT ALL WORKS. ON MY SONS SUNL 150 SPORT I HAVE TRIED COMBINATIONS OF THINGS AND GOT THE SUSPENSION DIALED IN PRETTY GOOD.

REAR SUSPENSION:

THE STOCK REAR MONO SHOCK ON THESE MACHINES ARE HORRIBLE AT BEST STIFF AND OVER SPRUNG FOR SUCH A LITE MACHINE, WHAT WE DID WAS USE ONE OF THE FRONT SHOCKS IN THE BACK, IT BOLTS RIGHT IN YOU JUST NEED TO REMOVE THE BUSHINGS FROM THE ORIG REAR SHAOCK AND INTALL IT ON THE FRONT ONE YOUR GOING TO USE, IT MAKES A WORLD OF DIFFERENCE, SOFT WITH GOOD RIDE AND DAMPENING

FRONT SUSPENSION:

I HAVE TRIED A FEW COMBOS BEFORE I CAME UP WITH ONE THAT WORKS. I BOUGHT OFF EBAY A GOOD USED SET OF HONDA TRX250EX FRONT SHOCKS OF A 2006 MODEL BUT ANY YR TRX 250EX OR 300EX WILL WORK, YOU WILL HOWEVER NEED TO TRIM 1/8" ON EACH SIDE ON THE LOWER MOUNT EYE TO FIT THE STOCK LOWER SHOCK MOUNTS, I TOOK MINE TO A FRIENDS MACHINE SHOP HE DID IT IN 10MINS ON A BAND SAW. THE HONDA SHOCKS AR 1.5" SHORTER AND IT LOWERS THE FRONT SLIGHTLY BUT DOES NOT EFFECT RIDE OR HANDLING. THE ONE STEP I DID TO GO FURTHER WAS TO RELOCATE THE UPPER SHOCK MOUNTS WE HAD A SET OF BRACKETS CUT ON A FRIENDS WATER JET MACHINE OFF TEMPLETS I MADE AND I RELOCATED THE SHOCKS MORE UPRIGHT, THIS MADE A BIG DIFFERNCE IN RIDE, I LOOKED AT THE HONDA AND BASICALLY POSITIONED THE AT THE SAME UPRIGHT ANGLE I WILL POST PICS OF THE ITEMS TALKED ABOUT HERE SOON, FEEL FREE TO EMAIL FOR INFO, THANKS

ALL THE PARTS YOU NEED TO MODIFY THESE ENGINES YOU CAN FIND ON THE WEB AND ON EBAY, I PRETTY MUCH BOUGHT EVERTHING I NEED FROM EBAY, BUT THERE ARE ALOT OF SUPPLIERS ONLINE AS WELL