Q-matic EZmotorbikes, Does anybody have any recent experience with them?

So if you want 15-20% more power from the HS142F, you
have to clean the plastic insert under the idle screw with
a 0.010 wire, drill a 1/4 inch hole in the little cover plate over the
intake, ream out the fuel jet to 0.026 inch, and drill holes
in the outer air filter cover, to allow more air. All this is
a 1-2 hour job, easy, peasy. I also have a straight 7/8 inch
flex pipe exhuast. Get this from Quenton.

Drill 8-9, 1/4 holes on the outer air filter cover. Purchase a 0.026
inch dia bit online and chuck. Remove the carb. Remove the small fuel
jet by unscrewing it deep inside the carb with a small screw driver.
This jet has a 0.021 hole. With your hands and the bit in a small
chuck, I simple reamed the hole to 0.026. Follow affordable
karts.com, and drill a 1/4 inch hole in the tab or cover plate that covers the intake
carb hole. Reassemble the carb, with the drilled tab, the filter, and the
outer air filter filter cover with the 1/4 inch holes, and you're
done. I don't have pics but pics are on the affordable karts
site, above. Very simple and fast.
I think with high gearing the stock Huasheng 49cc should reach about 35-37mph. With your mods to the exhaust and carburetor I believe that engine geared high will run at 40 to 45mph without rev limiters.
Yes, Quenton Gunther and vice president of Easy MotorBike Co. Mike Simpson are good people. They are honest and extremely knowledgeable. They are almost always next to the phone to answer your call.
I'm not sure what your top speed would be but I'd like to know and see a
speed run. Not sure if it is a good idea to remove the rpm limiter on the
engine. I wouldn't do it, but that's me.
Hey, thanks for all your input. I talked to Mike simpson for about a half hour and he seems like a really good guy. And helpful. I just wanted to hear others experiences with them before I pull the trigger on a $300 trans.
I realize this may be too late to be helpful, but there is a great gearbox for the straight shaft engines that will run for years. It's made in a machine shop in Oklahoma, not China. http://www.staton-inc.com/store/index.php?p=product&id=834

18.75 to 1 INSIDE DRIVE Reduction Staton gearbox with short shaft.

This gearbox will mount to the Honda GX50 49.4cc, GX35, 35.8cc Four Cycle, Zenoah G430RC (G43L) 41.5cc 1.97 hp two cycle, Tanaka Pure Fire PF-4000 (4210) 39.8 cc 2.2 hp Two Cycle and other with the same clutch rotor and bolt pattern.

The output shaft comes back towards the engine. It's CNC machined and has Six High speed Double sealed ball bearings, 1/2" thick gears.

I spent several hours yesterday trying to find a Honda clone with a 5/8" straight keyed shaft. I viewed over 100 dealers selling the engine; all with tapered shafts.

If you have an HS142F with a 5/8" straight keyed shaft, please guide me to the source. I just bought a Giant Cypress DX, I'm 68 and need help on our steep hills.

Thanks, I hope someone here can enjoy their bike much more with this gearbox.


  • mxcp_1619085355704_2362-2.jpg
    108.7 KB · Views: 156
  • mxcp_1619085472453_2362-4.jpg
    113.6 KB · Views: 158
I'm pretty sold on the Q-matic. But thanks for the suggestion on the staton. Did you get the link that I sent you for the kit?