Running 2003 merc elpto on nitro fish and ski with 19” laser II prop on 6” manual jackplate. Total motor hours less than 500. Normally by myself with fishing gear I run 5200-5250 rpm and right at 44-45 gps. With one extra angler, tons of gear and full livewell 42.4 gps is top recorded speed (though didn’t check rpm assume somewhere in 5100 range).

Last weekend at club tourney motor suddenly stopped wanting to push a load. Top speed dropped to 33 mph with two ppl, gear and full Livewell, rpms acted like still in mid 4000’s range. I was worried I had dropped a cylinder, but when I revved in neutral, it popped right up to redline like not a problem in the world. Also suuuuuuper slow to get on plane. Water pressure and pee hole no problem.

So I run Star-tron in every tank, change fuel filter and plugs every year without fail. Only two things I haven’t done this spring have been motor decarb and lower unit lube change (less than 40 motor hours since last time done though). Prop is fine no dings or dents but haven’t pulled to check hub.

Any ideas on cause? Just trying to get idea of where to start on the troubleshoot. I DID have nearly empty tank and put in 8 gallons of regular 87 octane (yes, ethanol included) on way to tourney that morning. Bad batch maybe? Also put slightly cheaper oil in reservoir as well. Could it be something slightly more serious like a reed pedal popped off? Pull prop and check flo torque hub? It was early and I hadn’t had coffee, sue me! Any event ideas or insight on this issue would be greatly appreciated. Thanks!