The motor: 93 Johnson 70HP J70TLETS running premix 50:1 BRP XD50 oil with ethanol free 93 octane gas and the occasional bottle of seafoam. Motor has pretty low hours on it and has never seen a day of saltwater use.
The problem: Every now and then my motor kicks in to SLOW. When it does I shut it off, start it right back up and off on my merry way I go. Temperature is within range (160 cruising, 180ish putting around). Water pressure is good (about 8psi putting and in the mid to high 20's when cruising). Water jackets are nice and clean, Temperature switch is good, I've checked it several times in a calibrated temperature bath it always opens and closes at the same temperature +/- a degree, gauge and sender are also relatively accurate. The motor has been overheated once, to the point that the alarm sounded (190 degrees). As soon as I heard the alarm I shut it off threw the trolling motor in the water and eased back to the dock.
What I've done: New water pump and thermostat took care of the cooling. I also flushed the motor every way imaginable. Cleaned every single electrical connection.
What I'm thinking: I've considered changing the blocking diode but I've never heard of a diode that sometimes stops doing what it does. It either does all the time or don't all the time. I'm also considering putting a new powerpack on it, maybe it's getting warm and flaking out. Anyway that's what I got and am looking for any other ideas. Any help would be much appreciated.
The problem: Every now and then my motor kicks in to SLOW. When it does I shut it off, start it right back up and off on my merry way I go. Temperature is within range (160 cruising, 180ish putting around). Water pressure is good (about 8psi putting and in the mid to high 20's when cruising). Water jackets are nice and clean, Temperature switch is good, I've checked it several times in a calibrated temperature bath it always opens and closes at the same temperature +/- a degree, gauge and sender are also relatively accurate. The motor has been overheated once, to the point that the alarm sounded (190 degrees). As soon as I heard the alarm I shut it off threw the trolling motor in the water and eased back to the dock.
What I've done: New water pump and thermostat took care of the cooling. I also flushed the motor every way imaginable. Cleaned every single electrical connection.
What I'm thinking: I've considered changing the blocking diode but I've never heard of a diode that sometimes stops doing what it does. It either does all the time or don't all the time. I'm also considering putting a new powerpack on it, maybe it's getting warm and flaking out. Anyway that's what I got and am looking for any other ideas. Any help would be much appreciated.