Upgrade your bike with a high compression piston! If you're gonna change your piston anyway, isn't it about time you get one with more power? The high compression piston increases the compression and gives you more power! Over 35 years experience in piston production! Pistons from ProX is a perfect choice when it's time for piston replacement
ProX is one of the world's largest manufacturer of racing pistons. They have provided the market with good and affordable pistons since 1975. ProX pistons are just as good as your original piston, but we sell them at much lower price.
The Pistons are made from Aerospace aluminium and CNC machined from one piece for optimal shape and long life.
4-stroke pistons are forged in Taiwan and CNC machined in Japan.
All pistons come with piston rings, piston pin and clips of the best quality possible.
Choosing your piston:
B-size piston is recommended for all used cylinders.
A-size piston is for new cylinders only.
A B-size piston is one hundredth of a millimetre larger than an A-size piston, in order to compensate for wear and tear. The C-size piston is larger than the B-size piston etc..
When changing the Piston:
If the old piston is defective, find out why and correct the error. Wrong fuel mixture, too low a heat range of spark plugs, faulty ignition setting or air leakage are leading causes of burned pistons.
If the old piston has fragmented or completely burned through, remove the crank case and carefully clean it from metal debris.
Check the cylinder for wear, conicity and ovality. A piston is worn down unevenly and it's therefore important to check the measurements of the piston properly.
When installing the piston:
Always replace old gaskets with new ones!
The piston is mounted with the arrow pointing towards the exhaust side. Piston pin lock rings are placed carefully with the lock slot down.
Install the piston rings on the piston. Be aware that some pistons are equipped with keystone piston rings. These are tapered and can easily be positioned incorrectly. Make sure the piston ring is completely into the ring groove and the ring gap closes. Lubricate all parts with engine oil 10W30 or 10W40.
Place a new cylinder base gasket on the crankcase, compressing the piston rings, gently slide down the cylinder in position. Before installing the cylinder head, the crankshaft is rotated by hand. Check that the piston rings to move freely within the cylinder.
New pistons require some break in. Adjust the carburettor to a slightly richer fuel mixture. Avoid riding at extremely high or low speeds, vary the riding speed and do not acceleration at full throttle. After an engine overhaul additional oil should be added to the fuel.
Pistons are manufactured in very large series and the material is just a very, very small part of production costs. This means that no manufacturers will choose poor materials. If a new piston brakes down, it is not because of the piston! Common errors are that the piston have been mounted in an unevenly worn cylinder, faulty mounted piston rings, faulty carburettor setting, improper fuel mixture, or other damage to the connecting rod / crankshaft.
ProX is one of the world's largest manufacturer of racing pistons. They have provided the market with good and affordable pistons since 1975. ProX pistons are just as good as your original piston, but we sell them at much lower price.
The Pistons are made from Aerospace aluminium and CNC machined from one piece for optimal shape and long life.
4-stroke pistons are forged in Taiwan and CNC machined in Japan.
All pistons come with piston rings, piston pin and clips of the best quality possible.
Choosing your piston:
B-size piston is recommended for all used cylinders.
A-size piston is for new cylinders only.
A B-size piston is one hundredth of a millimetre larger than an A-size piston, in order to compensate for wear and tear. The C-size piston is larger than the B-size piston etc..
When changing the Piston:
If the old piston is defective, find out why and correct the error. Wrong fuel mixture, too low a heat range of spark plugs, faulty ignition setting or air leakage are leading causes of burned pistons.
If the old piston has fragmented or completely burned through, remove the crank case and carefully clean it from metal debris.
Check the cylinder for wear, conicity and ovality. A piston is worn down unevenly and it's therefore important to check the measurements of the piston properly.
When installing the piston:
Always replace old gaskets with new ones!
The piston is mounted with the arrow pointing towards the exhaust side. Piston pin lock rings are placed carefully with the lock slot down.
Install the piston rings on the piston. Be aware that some pistons are equipped with keystone piston rings. These are tapered and can easily be positioned incorrectly. Make sure the piston ring is completely into the ring groove and the ring gap closes. Lubricate all parts with engine oil 10W30 or 10W40.
Place a new cylinder base gasket on the crankcase, compressing the piston rings, gently slide down the cylinder in position. Before installing the cylinder head, the crankshaft is rotated by hand. Check that the piston rings to move freely within the cylinder.
New pistons require some break in. Adjust the carburettor to a slightly richer fuel mixture. Avoid riding at extremely high or low speeds, vary the riding speed and do not acceleration at full throttle. After an engine overhaul additional oil should be added to the fuel.
Pistons are manufactured in very large series and the material is just a very, very small part of production costs. This means that no manufacturers will choose poor materials. If a new piston brakes down, it is not because of the piston! Common errors are that the piston have been mounted in an unevenly worn cylinder, faulty mounted piston rings, faulty carburettor setting, improper fuel mixture, or other damage to the connecting rod / crankshaft.