I blew my old powerhead and have just received it back with an out of the box powerhead from Yamaha. Outboard is a 2008 90hp 2-stroke.

The service technician put roughly 1 hour of break-in on it for me, and I hope to start adding to that on Friday. In reading the owner's manual, it states that after the first hour you are ok to run at half throttle and then run up to WOT for approx. 1 minute, then back off to let it cool back down. Following hour 2, and through hour 8, same thing applies but to 3/4 throttle. Hours 9-10 fine running WOT but vary speeds every 5 minutes or so. This is a little different than what I was told by service technician.

Any advice you gurus have on ensuring I do the right things would be greatly appreciated. I am concerned about causing damage during hours 2-10 of operation.

Break it in hard, and it'll run hard, break it in easy, it'll never run hard.

I like to stress it hard the first two hours, after that it's pretty well as good as it can get. With the trim down and putting some torque on the motor, I run it up and down the rpm range those first two hours, lots of hard acceleration.

You're response makes sense, but should I be concerned going against recommendation in owner's manual? Also, it say run additional oil in the gas tank, but in speaking with the service center that replaced powerhead, they said it isn't a big deal and I don't think they did this for the 1st hour break-in they covered.

If it ran the 1st hour it should be fine.

New motors all have down loadable CPU's. To easy to have warranty voided if you don't follow MFG. break in procedures.

I'm not *voiding* the warranty, I'm clarifying.

being a yamaha tech i would vote on manufactures suggested break in procedure and i would definately double oil the first full tank of fuel....as for being able to look at the cpu to see if the proper breakin was followed.....not true for this motor ....the ONLY yamaha two stroke that can be linked to a computer is the HPDI.....i would also suggest running ring free to keep the internal engine commponents clean....its really some amazing stuff