Just noticed this thread, I have an 87 226 with 88 Johnson 140 loopers. Mine run 3 blade 14.5 / 19 pitch and will run up to 5700 rpm and 44 mph, the heavy boat shoots out of the hole and gets on plane very quickly. I would check your carbs and make sure they are freshly rebuilt, float levels are very critical to get them running correctly. Also wiring harnesses on the engines need to be checked, mine had corrosion where the wires went into the end connectors and the big red harness connector. I was told to not lug these motors with too much prop bite, they like rpms. Also check compression in each cylinder to make sure all are healthy, I also checked my timing and adjustments for idle and WOT. WOT RPM range listed for these outboards are 5500 - 6000 with HP being measured at 5500.