Concave or convex piston?

[Sellout]

Hey all,

I am rebuilding (another) NQ50 and have found something that has intrigued me... While changing the cylinder head & piston (cos the old one is scratched and heavily gouged) I have found in my box of spares a piston with a concave head (the top of the piston goes "in" towards the bottom of the bike) whereas the piston that I have taken out of the engine is convex (so it goes "up" towards the spark plug)

What is better? Is there a real difference? Should I put a concave or a convex in?

Cheers!!

[vinnieh]

Hey sellout,

Check this out:

http://www.hondaspree.net/phpBB2/viewtopic.php?t=2584

[pete376403]

Obviously with the concave piston you end up with lower compression, if that was a concern.