Big Bore Kits for Popular 49cc Chinese Scooters (QMB139 Engine)

In stock form, the average 4-stroke 49cc Chinese scooter is painfully slow.

That’s if it runs well. If it doesn’t run well, it doesn’t go anywhere at all.

One of the best ways to make a Chinese scoot run a lot better is to install a big bore kit in the engine.

This bumps your displacement from 49cc to 80cc.

The stock piston in your engine measures 39mm wide. The new, kit piston measures 47mm.

Check out this short, 1 minute video of me installing a big bore kit on a customer’s Chinese scooter.

After installing the big bore kit, your Chinese scooter will run well and be much faster than it was before.

Parts are $50.

Labor is $195.

Shop supplies are $3.35.

Service call is $25 in Colorado Springs, $25 in Denver south of 6th Ave, $50 north of 6th Ave. Or $75 for Pueblo and Ft. Collins.

“All in” your big bore kit installation runs between $273.35 and $323.35, depending on where you’re located.

MOTO2N is a mobile service, which means I come to you and do the work on your turf. There is no shop, nor is there any need to transport your bike to a shop for service or repairs. In the event that it’s more convenient for me to work on your bike at my home, I transport and deliver it when the work is finished for no extra charge.

Call (719) 565-9295 or click on the “Book an Appointment” button to your right to schedule an appointment.