1997 Evinrude 35 hp start/nostart

I'm a brand new member and this is my first posting. I'm working on a multi-family owned pontoon with a 1997 35 hp 3 cylinder Evinrude.

The original report was the engine was missing out badly. I knew we were running a tank of gas that included some left over from last season so I put some fresh 93 octane in a 6 gal tank and plugged that in. I also replaced the plugs with the proper gap and replaced the fuel filter. The boat started every time and idled smoothly under no load, it seemed smooth up to what the tach said was 4000 rpm. I ran it 35 or 40 min on the lake. It ran smoothly until the tach said it was over 4000 rpm then it over reved, the tach showing over 6000 rpm without changing the throttle. It would run very fast for a couple of seconds then slow down and in most cases die. Then it would restart and I could run it at 1000, 2000, 3000 & 4000 without problems then it would go nuts as I approached 5000 rpm.

I then pulled the plugs again to see how they looked. They were fine but then it refused to start. I pulled #1 and it had no spark. I pulled #2 to check for spark and the thing started and ran too well to be running on a single cylinder. I could try the starter several times and have no start at all and a few seconds later it would fire up and run smoothly as soon as I hit the starter.

I'm thinking I have at least 2 problems but thought I'd throw this out to you guys to see what suggestions you might have.

Thanks

PS I tried to post this an hour or so ago but I never saw it come up so this might show up as a repeat.

Re: 1997 Evinrude 35 hp start/nostart

for some reason your original post did not post.

is the vent open on the fuel tank. when they get to running low on fuel, the start to run lean, and rev higher, then die. but dieing, allowed air into the system thru the empty carbs, as the float needles were open. did the fuel line bulb go flat. did you try pumping the bulb when it acted up.

also could be clogged fuel pick up in the tank, i really does not sound like a coil or power pack failing.

Re: 1997 Evinrude 35 hp start/nostart

tashasdaddy said:

for some reason your original post did not post.

is the vent open on the fuel tank. when they get to running low on fuel, the start to run lean, and rev higher, then die. but dieing, allowed air into the system thru the empty carbs, as the float needles were open. did the fuel line bulb go flat. did you try pumping the bulb when it acted up.

also could be clogged fuel pick up in the tank, i really does not sound like a coil or power pack failing.

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I completely switched fuel systems by going from the big on-board tank to a 6 gal tank. I opened the vent and even made sure that was open by closing it and reopening it when the motor was running on it.

It's like a switch is being thrown turning the ignition completely off then back on, possibly related to the motor being raised up and down to help when I'm leaning over it to pull the plugs?? I'm beginning to wonder if there's some partial open in the wiring to the primary coil because when it shuts down, I think it's turning all the cylinders off then they just fire up again. When it works, it works pretty well until I hit that high rpm level that makes things go nuts.

Re: 1997 Evinrude 35 hp start/nostart

lbay said:

I completely switched fuel systems by going from the big on-board tank to a 6 gal tank. I opened the vent and even made sure that was open by closing it and reopening it when the motor was running on it.

It's like a switch is being thrown turning the ignition completely off then back on, possibly related to the motor being raised up and down to help when I'm leaning over it to pull the plugs?? I'm beginning to wonder if there's some partial open in the wiring to the primary coil because when it shuts down, I think it's turning all the cylinders off then they just fire up again. When it works, it works pretty well until I hit that high rpm level that makes things go nuts.

Click to expand...

One funny thing is that the bulb on the on-board line would not pump up, but the one on the 6 gal tank stayed firm, but I was having the same symptoms with both of them.

Re: 1997 Evinrude 35 hp start/nostart

If it's just cutting out like that, have you checked/inspected the emergency kill switch and the wiring involved with it? Perhaps it's not plugged in all the way or is going bad, or could (as you said) have a fault in the wiring somewhere causing it to short when you tilt it.

Re: 1997 Evinrude 35 hp start/nostart

HybridMX6 said:

If it's just cutting out like that, have you checked/inspected the emergency kill switch and the wiring involved with it? Perhaps it's not plugged in all the way or is going bad, or could (as you said) have a fault in the wiring somewhere causing it to short when you tilt it.

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If I'm interpreting "emergency kill switch" correctly, the boat doesn't have one, just a blank place on the console where I'd expect the safety device to plug in. Is it likely there's something that went wrong in the ignition switch? I guess the emergency kill would go through there and is just jumpered since we don't have an actual switch.

We did have trouble getting the key out of the ignition switch, but simply lubed it up and it seems to be working OK mechanically now.

Re: 1997 Evinrude 35 hp start/nostart

an over-rev could be a spun prop, or cavitation, but that would not be followed by a slow down and die.

Re: 1997 Evinrude 35 hp start/nostart

HybridMX6 said:

If it's just cutting out like that, have you checked/inspected the emergency kill switch and the wiring involved with it? Perhaps it's not plugged in all the way or is going bad, or could (as you said) have a fault in the wiring somewhere causing it to short when you tilt it.

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I think I'll take my VOM and run continuity checks on engine wiring while cycling the tilt up and down to see if I can find something. It'll take some luck but I don't know what else to try.