Now who wouldn't purchase a motorbike for $85. Basically it was a 30mph capable, gas sipping, oil burning, axel breaking piece of machinery. Now that its gone, I honestly miss it. It was my first attempt on motorized bikes. Obviously there were some major issues but in the end, it was capable of going from A to B and having you smell like oily exhaust fumes at the end of the ride. Out of the box it had carburetor tuning issues where the needle was set to too rich as well as a snapped 146mm rear bike axel. After I brought it into my shop is when the real fun began. She could finally stretch out her legs.
SPECS:
26" Front & Rear Rims
146mm and 100mm rear/front axel
1L gas tank
80cc 2 Stroke Engine, 10mm Carburetor, 4.8:1 Final Drive Ratio
415 Drive Chain (0.5in pitch)
Standard MTB Frame
CDI (Capacitor Discharged Ignition) & B7HS Sparkplug
When I first purchased the bike it had issues with fuel delivery, carburetor tuning, and chain tensioning and alignment. I fixed most of these issues by installing a new rear axel, new fuel lines, carb cleaning, tuning with the needle, and a proper engine alignment with the rear sprocket as well as the correct chain tensioning
I mostly ran a premix ratio of 35:1 since this is a two stroke engine it has a combustion event every full rotation of the crank shaft or two strokes of the piston. It completes compression and intake in the same stroke as well as a combustion and exhaust event in the same stroke.
As you can see, a two-stroke engine completes a full combustion cycle every two movements of the piston (one upward and one downward stroke), which corresponds to a single 360-degree rotation of the crankshaft. Because the crankcase area is exposed to the intake fuel-air mixture, proper lubrication cannot be provided by a separate oil reservoir (oil pan) as in four-stroke engines. Instead, the fuel must be premixed with a specially formulated two-stroke oil. This oil is designed to burn cleanly with the gasoline, minimizing ash deposits and reducing the excessive carbon buildup inside the combustion chamber and exhaust system. Typically when breaking in the motor it is preferred to use a heavier premix ratio of 20:1 and after the break in period 40-50:1
The Motor that came with my bike did not have a reed valve which is a flap on the intake port designed to close from the inside to prevent the fuel and air mixture from leaking back out the intake port when the piston moves down, compressing the air fuel mixture in the crankcase before sending it to the combustion chamber through the transfer ports.