Never had a small block merc.
Before i pull the motor can anyone tell me what flywheel i need.
The boat is 1994.
Motor model is MCM 5.7,Thunderbolt V ignition and 2 barrel carb.
Is it the 168 tooth?Internal or external?

Thanks for any help.

It should be a 168 tooth external (flywheel has imbalance) balance for a one piece rear main seal crankshaft. It could be a 153 tooth, but not likely.

http://www.summitracing.com/parts/zzz-50-6525/overview/