Rolling Wrench
QMB139 GY650 Big Bore Performance Carburetor
QMB139 GY650 Big Bore Performance Carburetor
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Are you wanting to increase performance and improve how snappy your throttle is? Look no further! This QMB139 (GY6 50cc engine with big bore) carburetor kit comes with a round slide carburetor, Uni pod air filter, large ported intake manifold, throttle cable and jets! Not to mention, this is all put together! This is a drop in kit! We send the carburetor out with a base tune for sea level altitude. You most likely will need to fine tune the carburetor. This is by far one of the best upgrades you can add to your 80cc - 100cc GY6 big bore kit.
WE RECOMMEND PORT MATCHING THE HEAD TO THE INTAKE FOR A SMOOTH TRANSFER OF AIR.
Installed Jet:
Pilot: 38
Main: 135
If you want to take the guess work out of any tuning you may need to do, check out our Wide Band O2 Sensor.
EXTRA PILOT JETS INCLUDED:
32, 35, 38, 40, 42, 45, 48, 50, 52, 55
EXTRA MAIN JETS INCLUDED:
100, 105, 108, 110, 115, 120, 125, 130, 135, 140
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I absolutely love this carburetor! My bike is a whole nother animal after doing the 90cc Big bore kit, installing this carburetor with a cold air intake. I also have a red line racing clutch and variator with sliders. I wait for my paycheck every other week to buy the next add-on from you guys! I found my new obsession!
This carburetor kit is very good quality, I used it with my new BBK and it made i very snappy and brought into a BEAST!!. Would recommend it anyone.
Float hight needed some adjustments (to be expected with all the different gy6s) , aluminum casting had to be cleaned up out of the fuel bowl
Everything came well packed. Im pushing my 50cc to its limits. 55 so far. I have more polishing to do. Will be using you guys again for parts. My next conversion is electric, but for now im running her till she blows up lol nitrous next. It will take some serious tuning so remember the big bore helps you get more power to the cvt. Thats where the real fun begins. Recomend on 89.5mm variator and 5g to 6.5 with a 788 belt 4.5 to 5.5 for hilly and fat boys likevme 260lbs. If you move up in variator, be sure to check starter clearance. You may need to kick start.
Thank you guys for letting an old dog feel young again lol
Need more parts like this big up grade