Fine tuning your ZBox engine for optimum performance
Your ZBox engine is uncomplicated by design and hasn't changed over the years. Small improvements to bearings, seals and other small components are the only changes to the original 2 stroke design.
With the engine's simplicity comes the benefit of being able to troubleshoot and rectify problems with a minimum of mechanical knowledge and tools. Below is a list of common problems that you may come across during installation and running your ZBox unit.
- Keep your spark plug clean with regular checking for carbon build up.
- The high tension lead between the ignition box and spark plug cap can vibrate loose during running and contact can be lost. Twist the HT lead clockwise at both ends to restore contact.
- Keep the magneto coil dry by maintaining a tight seal on the magneto cover plate to keep rain out. A dab of loctite is recommended on cover plate screws to stop it vibrating loose. To test your magneto; the resistance blue to black should read around 330ohms.
- Engine can be starved of fuel for several reasons. Firstly, check the seal is tight between carburetor and intake manifold and manifold to engine to avoid sucking in too much air in the fuel mix.
- A tight fitting fuel cap can cause a vacuum in the fuel tank and stifle fuel flow to engine. A small hole drilled in cap will eliminate this problem.
- If the fuel to air mix is still too lean and choke is constantly required, you should adjust the needle setting to increase fuel to air ratio. Do this by dropping the circlip on the needle down a notch or two.
- Of course, never use contaminated fuel and regularly check your filter on fuel tap is not obstructed.
- Regularly check head nuts for tightness. Natural vibration in the engine can cause them to shake loose and blow your head gasket. A dab of loctite on the head nuts is recommended.
- Keep exhaust clean by regularly removing bottom cap and degreasing the baffles. If exhaust gases cannot freely escape the combustion chamber you will experience severe lack of power.
- ZBox engine kits are fitted with 415 heavy duty chains. The chain will travel more smoothly and quietly over the drive sprocket if the sharp teeth are rounded off with a file or grinder.
- Liberally apply grease to chain, drive sprocket and bucking bar.
- Open cover plate on other side of engine and apply a small amount of grease to meshing clutch gears - don't overdo it or you may allow grease into the clutch and cause slipping.
- Put a drop of machine oil into the sheath of the clutch and throttle cables.
- The engine will gradually gain more power during and after the run-in period when it has properly loosened up.
THIS LIST IS NOWHERE NEAR COMPLETE BUT IT SHOULD SOLVE THE MOST COMMON PROBLEMS AND MAINTAIN OPTIMUM PERFORMANCE.
THE IMPORTANCE OF FOLLOWING THE CORRECT RUN-IN PRODURE CANNOT BE OVER EMPHASISED SO IT IS REPEATED HERE TO ENSURE A LONG ENGINE LIFE:
The engine is a 2 stroke design, therefore a petrol/oil mixture is necessary. During the first 500km run-in period, the ratio for the engine is 16 parts unleaded petrol to 1 part high- grade 2 stroke motorcycle oil (63ml/ litre).
After the run-in period, the ratio is increased to 20 parts petrol to 1 part oil (50ml/ litre). Be sure to mix fuel and oil before adding to tank - don't add separately.
Do not exceed 20km/h during run-in period. Speed may be increased to 35km/h after the first 500km.
Don’t run for more than 30 minutes during run-in period.
WARNING: FAILURE TO FOLLOW THESE DIRECTIONS WILL CAUSE ENGINE TO SEIZE.
2008 Installation by Keith Lane of Durack Qld.