TOTAL POCKET BIKES TUTORIALS

MODIFYING A AIR COOLED BIKE BIKE

I’ll discuss some of the most common mods to do to a air cooled pocket bike and why they are worth it.

Exhaust
The second stroke of a 2 stroke motor pulls in some air from the exhaust, if the dimensions of the expansion section of the pipe is perfectly tuned for the motor the exhaust will act as a turbo by supplying the motor with unburnt fuel and oxygen straight into the combustion chamber.

For air cooled bikes, the standard exhausts on the air cooled bikes don’t help very much in performance as the expansion pipe is quite small. The most recommended exhaust for air cooled bikes is the fatboy exhaust, it comes in 3 parts, the stinger, the expansion chamber and the C section that bolts to the motor.
This is by far the best mod to do as it increases the bikes performance throughout the rev range with a much stronger power band.

Head kits
Head kits are the most expensive mod to do but they will make a huge difference to the performance of the bike. Head kits replace the head and cylinder of your motor and come with everything you need, some even come with a full circle crankshaft (as a pose to a half circle) which will increase the performance of the motor too (the more balanced, the more efficient the motor works). There are a number of head kits available which have different compression ratios. These range from 13:1 right up to 15:1 and 17:1 (ethanol). The way these compression kits work is by having a smaller distance between the dome and the piston. As a result though the motor is harder to start when it’s cold (there is more force needed to get the motor moving) and it will take more physical effort with the pull start.

Timing key
You may have heard of a timing key before but you might be unsure whether or not it is worth doing. The basic workings is as follows, the flywheel has what is called a magneto inside, and as the flywheel spins the magneto section contacts the ignition coil, therefore powering the ignition coil. By using a timing key, it shifts the flywheel 10 degrees so that the ignition coil will fire slightly quicker.

Why does it benefit?
It benefits by firing the fuel mixture before the piston reaches the top of its stroke, it will as a result give the downward stroke slightly more power. The issue though is that not every bike responds the same way, some owners have actually noticed a decrease in performance but the mod is cheap enough to try, if you are not happy with the increase you can always use your original one.

Should I modify the bike myself?
I always think of mechanical things as giant lego sets, if someone has assembled it then it must be removable.
If you take the time to read up my tutorials then you should have no troubles but I do recommend that you think about it before attempting any work, if you are ever unsure I would recommend getting the professionals to do it. They may save you a lot of money and time in the long run.