The “M” means the engine type is a motorcycle (motor-cycle relates to scooters\atv\buggies as well). "Q" means is not a liquid-cooled but a forced-air-cooled engine. Simply means it’s a forced-air-cooled engine.
Cg engine vs gy6 engine upgrade#
So you can see their room for a bigger cylinder upgrade for the 139QMB engine as well, cover in blog share " About 139QMB 139QMB 49cc." "Īnother example: if it was a 139QMB the "39" would mean that it has a 39mm piston with a cylinder outer skirt of 44.78mm, which may vary by manufacturer slightly off by 0.2mm, allowing it to slip into the 139QMB engine's crankcase bore opening 52.5mm max. Which is covered in blog share " GY6 Engine. You can see there is room for a bigger cylinder skirt thus's piston size upgrade for the 157QMJ engine. And, vary by manufacture slightly by 0.2mm, its cylinder sleeve (skirt) could be 60.2mm which allows it to slip into a 157QMJ engine's crankcase bore opening 63mm. This shows the one-cylinder piston size in millimeters, for example, if the engine code is ".157QMJ", the piston size is 57mm. But why? Because their so many upgrades available for non-P type engines include performance camshaft, etc. So, parts are interchangeable as long as both are replaced cylinder and cylinder head from 1P and non-P. However, if both cylinder and cylinder head is swapped out it will be identical to the non-P GY6 139QMB engine. The P series engine has a taller cylinder head and a shallow recess cam seating that gives it slightly more performance than non-P GY6’s engine code. NOTE: If you have the letter “P” after example “1P”, stands for (P)air valve horizontal engine. All GY6 engines are single-cylinder with a single-piston, so this number will always be uno-one.
Cg engine vs gy6 engine how to#
The three digits and three letters set that follows is the important engine code that will cover here, and how to decipher these six-character codes.Ĭorresponds to the number of cylinders. The first two letters are the manufacture acronym for its’ make or model, "BN" means the Chinese scooter model "ZNEN" manufactured by Zhongneng Industry Group. The secondary number below is the engine's unique identification numbers (engine registration numbers).Įxample Engine Code (above) is “BN157QMJ” The first set of numbers above is the scooter engine code. GY6’s engine code is located on the lower side of CVT, just beside the oil drain bolt. Where do we locate GY6's engine code and how do we decipher what each character means?
Engine Code: "BN157QMJ" 150cc stock, GY6 (A-Block) 54mm stud spacing longcase 20" Locate and Decipher GY6’s Engine Code