205 cc Honda Conversion Piston (MTX 200) -MB DEVELOPMENTS- Lambretta TV 200, SX 200, DL 200, GP 200

Among the countless conversion cylinders from the early days of the Scooter Boy scene, the 205 Honda conversion is certainly the most popular—and, with the TS1, also the most commonly installed. Proper old-school, so to speak. 

The piston came from the Honda MTX 200, a motocross bike from the ’80s. At some point, the supply of original Honda pistons ran out, or they became prohibitively expensive. Mark has reissued the piston, and it’s available in 67.00 mm, 67.50 mm, 68.00 mm, 68.50 mm, and 69.00 mm.     

So, it’s the ideal piston for pulling that old Honda conversion out of storage and getting it back in shape. 

To use the piston in a Lambretta cylinder, you either had to use a crankshaft with a longer connecting rod or shorten the cylinder accordingly. There must be hundreds of Honda 205 conversions, some of which are still on the road today.

The cast piston comes as a complete kit with chrome-plated piston rings, piston pins, and retaining rings.

The piston crown profile matches that of the Honda piston. So it’s perfect for all existing Honda conversions with a compatible cylinder head. 

Like the original piston, the MB piston is marked with “IN” on the intake side. 

NOTE.....

These pistons use different piston rings than an original Honda part.
The top piston ring has a wedge/keystone shape and can only be installed in one direction, with the ring size marking facing the top of the piston crown.
The lower piston ring has a rectangular cross-section; these can be installed in either direction but must be mounted so that the ring size marking faces the top of the piston crown.
The lower piston ring does not fit into the upper groove.