Probably the simplest way to do these is to get a parts manual for both
engines and compare the part numbers. I think at a minimum you are
looking at a new piston, camshaft, and carburetor. Maybe even a new
head. Buying a new 6 might prove cheaper.
JR





Arnold wrote:
Hello,

Does anybody know how to convert a Mercury 4hp 4 stroke into a 6 hp.
Motorbloc and cu are the same.
The WOT of the 6hp is approx. 1000 rpm more then the 4 hp.
Thanks for any help

arnold