1985 25hp. Evinrude Motor cuts off at full throttle and idle after 10 minutes

[Rick Latta]

Initial problem occurred after running full throttal for about five miles. When I pulled it in to nuetral the motor cut off and would not restart. After approx. 10 minutes the motor restarted and took me back to the ramp at which time it repeated the same problem. In all cases after approx. 10 minutes it resarts but it now occurring (complete shut off) at full throttle and idle. I changed the plugs and checked the fuel filter screen. The problem is getting worst and I have now lost confidence in the relaiable of the motor. I dead in the water for now.<br /><br />------------------<br />Rickey Latta

 

[JB]

Re: 1985 25hp. Evinrude Motor cuts off at full throttle and idle after 10 minute

Re: 1985 25hp. Evinrude Motor cuts off at full throttle and idle after 10 minute

Howdy Rickey. When was the last time you replaced your water pump impeller? That OMC 25 is usually as reliable as a wheelbarrow, but only when treated with TLC. <br /><br />Your symptoms, as far as you describe them, are of overheat. This is also the third time today I have seen someone speak of running an engine wide open for extended periods. <br /><br />How well would you do stressed at 100% for 15 to 30 minutes?? You would DIE, pilgrim!!<br /><br />Let's talk about what CRUISE means. It means about 75% of full throttle, about 90 to 95% of top speed, and a stress level that most engines can bear indefinitely.<br /><br />That that engine can bear OVERSTRESS and not explode is tribute to OMC engineers.<br /><br />Lighten up, some, Rickey,<br /><br />Red sky at night. . . . . <br />JB

 

[Dunk]

Re: 1985 25hp. Evinrude Motor cuts off at full throttle and idle after 10 minute

Re: 1985 25hp. Evinrude Motor cuts off at full throttle and idle after 10 minute

This kind of problem is about impossible to cure from keyboard, but if I was going to start on that engine I'd start by replacing the key switch. Key switches can do all kinds of weird things. For 15-18 bucks it might just cure the problem. Also take note to make sure all the wires behind the key switch are clean and tight on the screws. It could be as simple as that. Something is shorting the kill circuit on the engine. Just replace one wire at a time from the old switch to the new one.<br /><br /> I'm not really up to snuff on the little engines and when they changed ignition systems to power pacs, but I'm guessing an 85 25hp has power pac. See the stalling has to be shutting down both cylinders. That eliminates the coils, because I doubt both would quit at the same time. If the engine has the old style ignition then she has whats called a Sensor coil under the flywheel that could be killing both cylinders. My next guess would be it's the power pac or that sensor coil if she has one. The key switch you can try yourself, but if your not familar with the ignition system on that engine I'd let a dealer put the meters on her.

 

[Rick Latta]

Re: 1985 25hp. Evinrude Motor cuts off at full throttle and idle after 10 minute

Re: 1985 25hp. Evinrude Motor cuts off at full throttle and idle after 10 minute

Thanks guy appreciate the direction you gave me. I guess I wasn't very clear when I said full throttle. Full throttle to me is 5300RPM therabout. Max throttle is 5500 therabout. Waterpump however seems to be just fine its pumping a good amount of water out. I removed the ignition switch and retighten all the connections as you suggested. Water temperature alarm came on when I first turned on the switch. I didnt, properly install the protected cover to keep the alarm contacts from hitting the throttle case (Dummy). Fixed that and change fuse under outboard cover. Started engine it ran fine here in the yard. Next step is to put it in the water and give it a try under a load (cruse speed). It did seem to sputter a little after about ten minutes but so bad that it killed the motor. Thanks again for your advice will keep you informed. You got me goint in the right direction. I hope.<br /><br />------------------<br />Rickey Latta