TOPIC: 65hp max advance

hi, i am going to be setting the max advance on a 1970ish 4 cylinder 65hp. i am using the instructions that i saved from this website a few years back, it says to set it at 34 degrees for a crossflow. i just want to verify that this engine is a crossflow, i pulled a spark plug and looked at the top of the piston and it is the same type as the one in the attached photo.
thanks in advance

That engine is a crossflow design. My book sez max spark advance is set at 38 deg BTDC. You might want to dial it back just a bit, in deference to today's fuel quality. Highly recommended to run non-alcohol fuel if you can find it.

It'll run fine at 35-36 deg max spark advance. The older crossflow engines are not as prone to detonation as are the later 99-c.i. Inline Sixes.

Years ago I bought a 14' Fiberform runabout with a sick 65hp Merc, fixed the broken reeds and she did 37 mph down the lake. The boat was a lot faster with a 1000 Tower of Power (!) but I was pretty impressed with the turn of speed out of that 65. A good motor.

HTH and have fun with yours.........ed

thanks ed, it is on my 1968 14' starcraft that i replaced the transom on this past fall. Can't wait for some good weather.