Question for Optimax Owners

[Robert Jordan]

I purchased a new 75 Optimax a few days ago for my 2002 PT 175 Tracker. Our weather has been horrible here in Eastern Kentucky for the past month until the past two days. I got out and ran my new motor for a little over three hours today. The manual says to run the engine between 3000-4500 rpms the first hour keeping the motor in a verticle position changing speed every two minutes. During hours 2-4 you are to change speed every ten minutes. The manual is confusing to me at this point for I am not sure if you still are to run the motor in a verticle position or if you are allowed to trim the motor. During the first hour I could tell the engine was doing different things. It seemed to run smoother at some rpm's and a little rougher in other rpm ranges especially 3600-3800 rpm's. This all finally smoothed out. After I had three hours on the motor I trimmed the motor two times for ten seconds each just to see how much better the boat would handle and steer. I am not sure if I am going to be happy with the prop the dealer sold me but he indicated we could change it out if I am not happy. I guess I won't know until I can trim it out at wot. One other confusing thing is the dealer told me to run between 3000-4500 rpm's the first two hours in the verticle position and then I could run it up to 5000 rpm's until I had ten hours on the motor. I would like to hear from some of you 75 hp-125 hp Opti owners and see what you have experinced.

 

[Ed Fay]

Mercury Lawyers have to carefully word breakin procedure. Essentially, the rings do not seat properly unless they are under load. Since many boats operating at WOT (Wide Open Throttle) can go 60mph plus, lawyers cannot use the twenty-year-old basic rule of {first hour} WOT 1-2 minutes, cool off 1/2 throttle 5-10 minutes, and back on throttle again 1-2 (the WOT seats the rings under pressure but the cool off period allows heat buildup from tight tolerances to shrink back to shape) {second-third hour} WOT 3-4 minutes, 5-10 minutes cool off at 3/4 throttle {remainder of 10 hour breakin} avoid unnecessary idling (idling tends to polish the cylinder walls with the rings, rather than wear in under pressure the sealing surfaces needed for good fit and breakin) and vary speed often.

Mercury wants "load" on the Optimax so the computer can measure the breakin procedure (it double-oils until it gets sufficient breakin load - we once had an Opti customer come in complaining of excessive oil use - computer laptop told us he only had 2 hours breakin but 165 hours on motor because he started trolling as soon as boat passed breakwater - we had to have him trim motor under to create load from wet hull plowing, and run engine hard to clock breakin hours so the computer could stop running in breakin mode and go to normal oiling - fixed it) So you can create load by trimming under, by running hard - just be safe in all cases. You purchased a great motor - it only uses 1:400 oil:gas at idle and 1:80 oil:gas at WOT because it only oils the parts needed, not wetting the engine inside wastefully. It trumps a four-stroke every day of the week.