Scooterotica

...I swapped a standard 125 cylinder head for a 185 head. I've stripped the thread of the 185 and found a 125 head in the shed. Was wondering how it would affect the squish/compression etc. Not too mechanically minded about this sort of thing. Cheers.

as a quick fix without taking the trouble to measure volume/compression ratio etc you could try the 125 head with a thicker head packer/gasket i could work out/guesstimate a gasket size if of use