TOPPE KIT RACING 2 HEAD D.49.5 85CC AM6

Racing piston-cylinder unit Ø 49.5 for Maxi Kit 85cc. Part no. 9921760

Warning: Only fit together with crankshaft Part no. 9920410 !!!

Scope of delivery:

1 Cylinder Ø 49.5 mm in special “MINACROM” cast iron (with chrome additive)

1 Piston Ø 49.5 with high silicon content 

1 Chrome-plated steel piston ring 1 mm thick 

1 Piston gudgeon pin Ø 12 x 42 mm 

1 Roller bearing for gudgeon pin Ø 12 x 15 x 15 mm 

2 Gudgeon pin circlips 

1 Combustion chamber 

1 Combustion chamber cover 

8 O-ring Ø 7.66 x 1.78 in Viton, green 

1 O-ring Ø 53.7 x 1.78 in Viton, green 

1 O-ring Ø 22.22 x 2.62 in Viton, green 

1 O-ring Ø 28.24 x 2.62 in Viton, green 

1 O-ring Ø 104.37 x 3.54 

1 Reduction for temperature sensor 

1 Plug M14 x 1.25 

1 Aluminium gasket for plug M14 x 1.25 

1 Cylinder base gasket 0.5 mm 

1 Reduction bushing for exhaust from Ø 28 to Ø 25 mm

Bore: 49.5 mm

Stroke: 44 mm

Displacement: 85 cc.

Squish: 0.9 ± 0.1

Timing diagram: exhaust: 191° / transfer ports: 132°

Compression ratio: geometric: 14.7:1 / actual: 8:1

Recommended spark advance: 17° (1 mm before TDC)