Let's see. I purchased mine in February and it's now the last day of June. I've got 50.4 hours (just completed the 50 hour service) on my 2 stroke Yamaha 70. So, depending on weather the rest of the year, I would guess 150 hours is about right for boating once a week.
Engine overhaul times depend on the wear of the motor. One way to check is doing a compressiion check on a new motor (compression a bit low until breakin), one that has 50 hours (should be broken in now and at max compression) and continue every 50 hours. When compression begins to drop
or one cylinder is way different than the others, time for an overhaul.
This is why it's a good idea to purchase the service manual for your motor. The book gives lots of information and is great bathroom reading material.
