Pocket Bikes - Performance Tips

54cc 2 Stroke Full Spec Race Engine 

The easiest way to boost performance is to upgrade your standard 50cc engine to a 54cc engine.

These are 2 stroke air-cooled with full race spec engine:  2 PC split CNC cylinder head, larger piston kit, big bore kit, NGK race spark plug, 15mm race carb, 15mm race cone filter, and an alloy intake adaptor.

NGK Race Spark Plug

Upgrade your standard spark plug to a reputable NGK or NGK Race spark plug for a stronger more reliable spark.

Lightweight Race Flywheel

Upgrade your standard flywheel to a race spec, lightweight, flywheel.

Race Cone Filter

Upgrade your standard 13mm cone filter to a 15mm cone filter to maximise air intake – to be done in conjunction with carb upgrade from 13mm standard carb to a 15mm race carb

Race Carb

The bigger the carb (meaning bore and jets sizes) the more fuel you can introduce to the cylinder. A venturi bore speeds up the airflow across the main jet and pulls more fuel into a compressed mixture. We offer a 15mm race carb which makes a huge difference compared to the standard 13mm carb, allowing more fuel and air flow.

Reeds 

Stiffer reeds close tighter and faster sealing your precious air/fuel mixture into your case. This aids in the pre compression stage of your mixture. Stiffer reeds don’t flutter at higher rpm. Flutter creates turbulence before the charge reaches the combustion chamber.

Ported Head

Porting a head must include porting of the case at the transfer port bottom. Porting the head allows more fuel/air to enter the combustion chamber via lesser resistance and larger cross-sectional area.

Indexed/matched piston 

Indexing the piston effectively increases the transfer port size at the top. It also advances the intake timing, allowing more fresh charge into the combustion chamber. An angled “index” will guide the charge up and to the rear of the chamber which will swirl and create a vacuum at the front of the chamber. This helps scavenging and creates more space for the return pulse charge which makes your power band peak stronger, making your expansion chamber more effective.

Matching the piston is cleaning up the underside to maximize flow and to enlarge the transfer port at the bottom, this is mostly effective on the Cag piston port style motors.

Snake or Performance Pipe 

A properly tuned pipe will create a return pulse at precisely the right time and pack the left-over fresh charge back into the combustion chamber. At your power band peak this essentially acts like a turbo.

Performance 2 Spring Clutch 

We are mainly talking about the clutch engagement time here. If a clutch is set to engage at later rpm, you can build more horsepower before it engages. This will give you substantially more acceleration. The motor will rev faster, at the lower rpm, due to the lack of a load on the motor. This acts as if you have a lighter piston/crank, until engagement that is.

Sprockets

A bigger rear sprocket or smaller front pinion sprocket equals more acceleration.

A smaller rear sprocket or bigger front pinion sprocket equals less acceleration but more top-end.

Pinion to sprocket ration: 1:10 (1 pinion tooth to 10 sprocket teeth).

If you’re looking for a good all-round gear ratio to ride with every day, and you want better clutch pad life, stick with 7/72 or even 7/74.

You’ll have much better acceleration, but not quite the top speed as at 7/66 or at 7/68.

Also, try a 6-tooth pinion. It’s easier for your engine/clutch (as far as these centrifugal clutches go) to push a 6-tooth pinion than a 7-tooth.

We stock 6,7,8 tooth pinion / front sprockets and 60,62,64,66,68,70,72,74 tooth rear sprockets

What should I mod first?

  • Air filter upgrade from a 13mm to a 15mm and/or
  • Exhaust pipe upgrade to a race pipe
  • Re-gap spark plug spacing to .025 inches or you may also want to change to NGK race spark plug
  • Upgrade fuel line
  • Carb upgrade from a 13mm to a 15mm Race Carb
  • Light Weight Flywheel
  • Upgrade your clutch to a 2 Spring Race Clutch
  • Big Bore Kit Conversion – Either a Stage 1,2 or 3
  • Sprocket ratio conversion both front and rear