93octane waste of $ on my 77 85hp merc?

[paratrooper]

ive only run 93 thru this engine since ive had it for 5 yrs,does it matter ?87 or 93?cost is not an issue. thanks for the info,enjoy the site.

[Jay Smith]

I would do a compression check and if its a lower compression type motor 110 and lower I'd run the lower grade of fuel .You will see and increase of the money in your a** national and an increase in power lowering the octane if your compression is low as 110 ish , OVER octaning a 2 cycle will reduce the power it can make . If detonation is not an issue ( and at 110 ish it will not be ) you should be fine especially at sea level , make sure your timing is set correctly also........