I just bolted up a new 68cc Olympia kit to my '80 Garelli VIP. It's a daily driver, about 6 miles round-trip. Nothing crazy.
At TDC, the piston is shy of the top of the jug by ~0.5mm.
And at BDC, the piston comes down below the bottom of the exhaust and transfer ports by about the same 0.5mm.
I have the thinnest base gasket I can find on there. So my question is this: is it worth milling or lapping down the bottom of my jug to make up that 0.5mm? How much more will I gain out of doing so?
Pictures below. Thanks,
JR
[attachment 145996 TDC.JPG]
[attachment 145995 BDC.JPG]
At TDC, the piston is shy of the top of the jug by ~0.5mm.
And at BDC, the piston comes down below the bottom of the exhaust and transfer ports by about the same 0.5mm.
I have the thinnest base gasket I can find on there. So my question is this: is it worth milling or lapping down the bottom of my jug to make up that 0.5mm? How much more will I gain out of doing so?
Pictures below. Thanks,
JR
[attachment 145996 TDC.JPG]
[attachment 145995 BDC.JPG]