115 'Rude Power Loss

I have a 1993 115 Evinrude that has an aggravating problem. It starts ok and runs fine. After about 30 minutes of running (off and on) the engine will lose about 2,000 RPM (from 4,200 to about 2,400) and come off plane. The engine sounds normal otherwise. A trick that works once or twice is to back the throttle to idle, rev the engine to about 4,500 RPM and leave it there for 5 seconds, back to idle, in gear, and she will go for about another quarter mile, and then back to the same routine. After about the second or third revving episode, the engine takes about 10 seconds to get past 4,000 RPM, backfires a little, and the trick doesn't work anymore. The engine won't go any faster than about 2,400 RPM. What stumps me about this problem is the timing of the malfunction- it's consistent- 20 minutes up the lake to my favorite Marina, 30 minute park, and then the malfunction- at the same place every time, on my way back.<br /><br />I've replaced the plugs, water pump, and am in the process of draining/flushing the carbs. During one event, I got my wife to pump the primer bulb- no luck there either.<br /><br />Should I rebuild the carbs, or replace the stator and control box as my neighbor recommends?<br /><br />The Rockfish (Striped Bass) are destroying live eels in the Croatan Sound in coastal NC and my Grady-White does Rockfish really well.

Re: 115 'Rude Power Loss

SOUNDS TO ME YOU HAVE A IGNITION PROBLEM LIKE ONE OF THE POWERPACKS IS BREAKING DOWN WHEN THE ENGINE REACHES OPERATING TEMPATURE. OR POSSIBLY THERE IS TRASH FLOATING AROUND IN ONE OF THE CARBS OR COULD BE TRASH IN FUEL TANK TRY A DIFFERNT FUEL TANK OR TRY PUMPING PRIMER BULB WHEN PROBLEM OCCURS IF IT PICKS BACK UP YOU HAVE A BAD FUEL PUMP OR PUSH IN ON KEY SWITCH FOR A SECOND OR TWO IF PICKS UP THERE'S A PROBLEM IN THE CARBS HOPE THESE DIAGNOISTICS HELP

Re: 115 'Rude Power Loss

Thanks Mercman. I'm still tinkering with it. I'll let you know what the problem was.

Re: 115 'Rude Power Loss

Began checking the engine electrical system from the plugs back. Checked contacts in the wires and contact between the part and the engine. Found a wire running from the stator to the power pack that was toasted. Fixed wire, but the problem persisted. Replaced all 4 coils, power pack, and stator. Took the 'shotgun' approach, but hope this works. Had 2 OB mechanics involved too. No definite answer. This weekend will tell.

Re: 115 'Rude Power Loss

First I must say I am no expert .. REALLY. But I found this in the Clymer book.<br /><br />S.L.O.W. Operation and Testing.<br /><br />SLOW is the (speed limiting overheat warning)<br />“ The circuit is activated at 203 deg F. When activated the engine RPW will be limited to approx. 2500 RPM. To deactivate the temp must drop to 162 deg F and the engine must be stopped”<br />Could this be it?<br />I have all the info on this and the test stuff on how to see if is a faulty sensor etc. Let me know if you need it.<br /><br />Dave

Re: 115 'Rude Power Loss

I'm having the same problem listed here with an '86 evinrude 150. Replaced plugs, fuel, fuel line, and just had the carbs rebuilt. It seems one bank of cylinders is not getting a very strong spark. Would the power pack work off and on or just completely quit when it dies? Any information would be greatly appreciated.

Re: 115 'Rude Power Loss

Hey guys,<br /><br />I have an '85 Johnson 150 and have the same problem. I actually just posted a new message because I had been unable to fine this post before.<br /><br />I read a bit about the S.L.O.W. and thought that it might be getting set off incorrectly and I first thought that that was it. Two things that now make me think that it is something different- it does not hit the same RPM each time (between 1800 and 2500) and from the book it seems like you have to bring the boat to an idle for it to get back up to speed but sometimes it will take off again without adjusting the throtle.<br /><br />If any of you have figured out what it is please le tme know.<br /><br />Thanks,<br />Todd Lynch<br /><br />todd@shifteight.com

Re: 115 'Rude Power Loss

1985/86 150 does not have S.L.O.W.