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1994 Evinrude 40HP ignition issue? Engine reaches max RPM with ignition off!

jeralmac

New member
Hi all, I have a '94 Evinrude 40 that I'm about to take out fishing with the family next week. Before doing so, I usually test it in the yard with our hose covering the water intakes. Doing so yesterday, I experienced a very strange problem that has me baffled. I hooked up the hose and got it running. At mid RPM, it started to hang, even after backing off throttle. Did a few more revs and all of a sudden it hung and then never came back down. Reset throttle to idle and motor started climbing by itself all the way to full RPM. Pulled safety kill and it kept going - turned off ignition switch and it still kept going. Pulled fuel line and it stayed running for about 20-30 seconds until fuel ran out. Let it sit for a while and tried again after jiggling wires, checking contacts, etc.

Anyone ever heard of this happening? I've searched all over the web and different forums, include MarineEngine.com which I've used in the past and find nothing. Thanks in advance for any possible insight!

Jeremy
 
Its called engine runaway.NEVER run the engine high RPMs on the hose.Now a full engine check is in order start with compression check.Runaway can destroy a engine.The carbon deposits actually burn setting off the cylinder explosion instead of the plugs.
 
Hello

I have the same issue with 1994 40hp johnson. Its starts fine but when I increase the RPM's to 3000 is slowly climbs till it hits 4000 RPM then it jumps to 6000 RPM. I took it down to the lake and I can get the boat above 10 mph. Can anyone help me? Do I need to get the carbs rebuilt?
 
Hello

I have the same issue with 1994 40hp johnson. Its starts fine but when I increase the RPM's to 3000 is slowly climbs till it hits 4000 RPM then it jumps to 6000 RPM. I took it down to the lake and I can get the boat above 10 mph. Can anyone help me? Do I need to get the carbs rebuilt?
Well your stealing this thread should start your own.You do not have the same problem, yours sounds like a spun prop.
 
Dew2, thanks for your reply, very much appreciated. Now that you say that, it makes perfect sense. I had become too focused that I had an electrical short somewhere.

Would you be able to explain why it would do this on the hose rather than idling in the water? In other words, why is it not a good idea to run your motor on the hose? And why is it that it's happening this summer and not in the past years? Seems to me that based on what you're saying, I may have excessive carbon build up. Does this warrant a tear down and rebuild?
 
Does it still keep running now ( on a hose ) when you turn off the ignition ???------------------Never wind up a 2 stroke in nuetral.
 
If I just let it idle, then no - it shuts off with the ignition like it should. So if I put it in gear and rev it, is that OK?
 
No never rev an outboard with no load !!-------------In gear, in the driveway is really the same as nuetral.-----------No work to do for the motor.
 
Thanks racerone! I think my only concern is that the lake we go to in northern Wisconsin is about 2 hours from the nearest trustworthy boat parts shop so I like to see how the motor runs before I take it out there. Is there a way I can test it without driving over an hour to our nearest lake (3 hour process)?
 
Not sure why you need to test at full throttle before going to the lake ???-----------Always run carburetors dry when putting boat on the trailer.--------------You could do a compression test on a regular basis and check that you have spark on both.-------------There should be no need to want to test at full power at home !!!!-----------------There is the option of a MARINE DYNOMOMETER to test at full load in the driveway , but at $4000.00 for a new one it is a bit of " overkill "
 
my 1985 40 h.p. johnson goes to wot for no reason too..............no carbon, has new head gasket , clean carb's , new reed valves and gaskets..........cant seem to fix this problem........but somone will give a reply........keep looking, i am
 
No I do not think so.------------40 years of working on motors and have never seen this " problem "----------Must be something simple , but your motor is not on my " work bench "
 
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