2.5hp merc gas/oil ratio?

[slick2526]

Bought a 2000 or newer 2.5hp merc off a relative. Just curious what the gas to oil ratio should be? also what brand of oil and blend of gas are the best for theese motors? One more thing I dont think the motor has been ran in about 2-3 years should i run some sea foam or something of the sort through the first tank of gas?

[theoilman]

Almost all pre-mix 2-cycle outboards (for probably over the last 20 years) call for a 50-1 mix ratio - and assume conventional petroleum oils.

For best performance I recommend AMSOIL Saber Outboard mixed at 100-1 (full synthetic, burns away clean leaving no carbon, greatly reduced smoke to nearly smokeless, no 'oil slick', greatly reduced emissions (over 60% less) to leave water in much better condition for your fish!

Set for years? - definitely discard any old gas. If it wasn't left with gas stabilizer in it you will probably end up having to pull and rebuild the carburetor.