Looking for advice since, to be honest, this will be my FIRST mud motor. I am having a GT 17x50 built and it will have the Mud Buddy 4400 Black Death HDR on it. I've read that the first 10 hrs are the break in period. My question is, can someone give me their opinion on how to use it for the first 10 hrs. and break it down for me in hour sectors.????
I plan on running a fuel water separator on it (Racor 10micron system) us only good gas, and use Amsoil 10w-30 syn. oil in her. But as to breaking in this motor and what to do and not do during those first 10 hrs.... I have no idea... any advice?

Check your valve lash, seen a couple motors that were way out. Question how far they were out from factory, these were on stock BB Briggs?? Might save you a bent push rod. Also I would try to keep it off rev limiter for the first few hours. We run 15w 40 Rotella in all our motors, and add Marine Stabile to our gas to combat break down from condensate build up in our tanks. We check torque on all crank case bolts every 10 hours also.

My 2c worth. Dont put synthetic oil till after break in. synthetic oil can keep the rings from seating well during break in. Dont let it ldle for long periods. The cam needs good oil splash For lube and to keep lifters spinning. Dont run wide open for more than a couple seconds at a time during breakin. As for the lawnmower coment,,, mowers do not run at 100% load like these boats do. I built my first engine 30 yrs ago and i crindge when someone runs the dogshit out of a new motor

Follow what they tell you to do in the Briggs and Stratton manual. No reason not to and they put that info in there for a reason.