this does not exactly translate to a 50cc small case GY6 engine, but expect the small case GY6 to behave in a similar manner when comparing a 50 to a 72 or 82
what it appears to show is that porting and polishing plus larger valves increases power by about 20% and shifts the power band to a lower lower rpm range (about 500 rpm) and flattens the peak somewhat.
edited: no port and polish...
you also see the power falling significantly from peak to 9000 rpms
9000 rpm is kind of THE magic # for the small case GY6 as with stock gearing, 9000 = 50mph
Interesting, the big valve head has potential for flowing a lot more air, I wonder though about porting and polishing with normal valve sizes. Some think smaller valves create better velocity of flow in some applications.
its intersting to see that the stock bore and big valve head was that high in the power and held the power better at higher rpsm this is all stuff that is important when you are trying to plan your build by the looks if you want something that is great for top speed keep the stock bore and do the head if you want a brute off the line then do the bbk and head
gy6forlife: I am jason from Noblesville out in the corn fields and I am having a hell of a time getting my VIP 2007 W/A BBK TO PULL RPMS WITH ME ON IT,IT RAN LIKE A TOP FOR OVER 3 YEARS AND 12k MILE B 4 THE ISSUES STARTED AT THE CAR WASH,NOW THAT I HAVE IT BACK UP AND
Feb 16, 2013 16:33:12 GMT -5
gy6forlife: TRANSPROTATION FOR ME TO GET TO WORK AND MAKE MONEY?i HAVE ALL THE AFTERMARKET STUFF ON THE SHELF TO INSTALL BUT NOT TILL i GET THE WEAK PERFORMANCE OUT OF IT?PLEASE HELP MAN,THANKS FOR ANY INPUT YOU HAVE,AS YOU SEEM TO KNOW A TON ABOUT THESE ENGINES AND V
Feb 16, 2013 16:55:25 GMT -5
gy6forlife: VARIATORS AND SLIDERS AS I HAVE THEM ALL READY TO INSTALL BUT DONT WANT TO TILL IT IS RUNNING WELL AGAIN?I AM NEW TO THIS ,I TOOK IT TO THE CAR WASH,BIG MISTAKE,AND BURT UP STATOR,NOW RUNNING AGAIN,AND W/BBK 80CC VERSION FROM SCRAPPY?IT STARTS AND RUNS GRE
Feb 16, 2013 16:57:34 GMT -5
gy6forlife: GREAT ON STAND,ON THE WHEELS IT WONT GO PAST 20MPH?i TRIED THE #85/#35 JETS IT JUST STUMBLED AT ALL INTERVALS?i NEED THIS TO GET TO WORK MAN,IF YOU HAVE ANY THING TO INPUT,I THANK YOU FOR YOUR INPUT AND TIME,GY6FORLIFE,JASON
Feb 16, 2013 16:59:33 GMT -5
gy6forlife: IT NOW HAS THE STOCK JETS AND IT RUNS GOOD ON THE KICK STAND AND UNTILL I TRY TO RIDE IT ,IT IS A TOTAL DOG SHIET MAN,i DONT KNOW WHAT ELSE TO DO MAN?PLEASE HELPME?YU ARE A PRO AND MAY KNOW HNOW TO FIX IT?
Feb 16, 2013 17:01:27 GMT -5
gy6forlife: I HAVE SET A SIDE A koso PERFORMANCE VARIARTOR AND REAR LARGE/AND 3 SMALLER SPRINGS TO INSTALL ONCE i GET IT RUNNING CORRECTLY,BUT i PUT IT BACK TO STOCK TO START AT A KNOWN POINT?? EVEN THE CARB AND,i DID DO SOME PORTING TO THE HEAD JUST TO CLEAN UP THE C
Feb 16, 2013 17:06:42 GMT -5
gy6forlife: AS I BOUGHT ALL THE PERFORMANCE ,CDI,COIL,SLIDERS,GATES BELT,REAR 4 YELLOW SPRINGS AND I HAVE PULLED ALL THAT OUT AND PUT BACK TO STOCK,TO START FROM NORMAL CONDITIONS": CAN YOU HELP ME OUT MAN,AS i LOST ME JOB DUE TO NOT BEING ABLE TO GET THERE?ANY INF
Feb 16, 2013 17:12:17 GMT -5
gy6forlife: ANY INFO IS GREATLY APPRECIATED AND NEEDED MAN?THANKS FOR YOUR TIME AND UNDERSTANDING.Jason/GY6FOR LIFE ,ITS ALL BACK TO STOCK BUT THE BBK"SO IF YOU CAN i WILL BE OF GREAT UNDERSTANDING AND APPRECIATE ANY INFO ON WHAT TO DO:?
Feb 16, 2013 17:15:58 GMT -5
pumacyclessteve: the gy6 150 engine needs to have the oil changed more than most other scooters .the simple fact that the metalergy and the alloys are not the highest grade like the high end scooters .the errosoin and general wear down of the internal components.is slowe
Mar 1, 2013 18:51:10 GMT -5
pumacyclessteve: but i have a 150 that i ride hard i mean hard thats 5 years old and still runs like a bad as whith a power pros custom one off exhaust and a big valve head .i will wheelie at most every intersection just out pure confidence in my one trick pony.stay
Mar 1, 2013 19:04:53 GMT -5
Mar 2, 2013 18:49:26 GMT -5
mukradio: Help! I am working on a 50 cc that I can't get it to idle properly. It's starts off way too high and when it warms up, it dies. It's driving me nuts and it's a short trip! Any ideas? I have disassembled the carb and cleaned it, drained and replaced gas.
Mar 7, 2013 15:41:53 GMT -5
westonpersons: Adjust your valves to .006". There should be easy directions on youtube, otherwise just remove the valve cover and turn the flywheel so the engine is at top dead center, then adjust the 'taps' on the cam holder for the .006" gap.
Mar 8, 2013 15:02:33 GMT -5
mr cool guy dude: hi every body.......bananas
Mar 28, 2013 17:55:49 GMT -5