Piston 41,5x12 GOL PISTONI Tomos / Puch

1) The GOL piston is made in our Foundry , through chill-moulding . Using Aluminium-Silicon alloys 18% Magnesium 1% -Nickel 1% (AL-SI18 MG1-NI1) which have a limited coefficient of thermal expansion that permits the reduction of play between piston and cylinder for best possible use at all temperatures.
2) The piston is submitted to thermal stabilization treatment.
3) The skirt of piston is finished with diamond tools, according to original forms and ovalization.
4) The nominal size indicated on the piston head refers to cylinders with Zero tolerance . The arrows drowned on the piston head shows the way-out of exhaust gazes .
5) The piston already has its negative tolerance, wich is calculeted on the basis of thermal expansion of material and particular engines and cylinder characteristics .
6) The GOL piston is supplied with normal or special rings, pin and circlips or seeger.

ASSEMBLING INSTRUCTIONS
1) The piston pin must be mounted by using slight pressure on said pin or, at the most, by heating the piston sligtly.
2) Do not force piston pin entry with hammer or other tool, may be cause seizures of the pin hole and piston deformations.
3) Check position of connecting-rod is 90°angle with the piston pin axis, so the piston pin does not work incorrectly position.
4) The circlips or seeger must be mounted with special pliers, checking that are perfectly locked in their groove.

5) Only for 2 stroke engines : During the Ring's assembling you should control that the notch-rings are between the windows of cylinder
6) We recommend a short running-in , variable from 100 to 200 Km. During the running.in period of 2 strokes-engine , We recommend to use a richer mixture . Mix petrol+oil ... at twice the normal (example 2x2%=4% , or 2x3%=6% etc.etc.) . Use syntetic 2T Oil , of a superior quality .