Logo
FULL SITE MENU

Evinrude 5.5 Fuel/timing Question

thudpucker

thudpucker

Regular Contributor
I have this little guy. It pulls through with good compression.
The plugs are never Wet!
There is fire to the plugs.
The fuel line pump from the tank will drive the fuel all the way to the Carb.
When we pull it through, the plugs don't get wet.
It does not fire when I spray Carb Cleaner in to the carb.
I don't think the Fuel pump is pumping much as we pull it through.

I'm wondering if there is one single problem or two.
If the Key is sheared, I think it could cause all this.

Look at the Fuel pump in the photo. Is that the correct Pump? It sure is a large one. Bigger than the one on my Six Hp Johnson.

Fuel pump.jpgEvinrude numbers.jpgDSCF6081.jpg
 
Usually if you spray carb cleaner in the carb it will fire unless you don't have timed spark or compression. Have you taken a compression reading? Have you done an external spark test to confirm if the ignition is strong enough to jump a 1/4" gap. Are you sure the right plug boot is on the right plug. If they were reversed it will never start. Give them a switch to confirm.

I assume when you say "pulling it through" you mean that you are pulling on the starter rope. The primer bulb will get the fuel to the carb bowl. Once the motor is running or when you pull on the starter rope the fuel pump will take over in ensuring fuel gets to the carb bowl. As for the fuel getting up into the carb throat and into the combustion chamber, the fuel pump has nothing to do with that.
 
Yes, compression is above 100 on Both.
Wires are in the right place.
Plugs set in the wires will fire good.
Plugs are never Wet.

I was thinking the Key is sheared making the ignition fire at the wrong time.

When pulling it through (will the starter rope) that fuel pump should be forcing Gas to the Filter bowl and on into the carb. It does NOT do that.
It won't fire with a spray of Carb cleaner which is telling me there is Fire in the wrong timing. No Fire at the Compression stroke.
I'm think that is the problem with the fuel pump too.
 
Sorry, if the key is sheared and the flywheel is in the wrong position , then there is NO spark.-------The points are timed to the magnets on the flywheel ( hence the term " magneto " ) for these things.----A proper spark test is to use a spark checker with a gap of 1/4" or more.-----Laying the plugs on the block is not a very good test.
 
On an electronic ignition magneto a sheared key will produce spark at the wrong time.--------In a cylinder with the mixture compressed you need a stronger spark than what is needed to jump the gap of 0.030 in free air at atmospheric pressure.-------Have you pulled the flywheel to inspect both of the coils ??
 
We'll know tomorrow. I'll pull that Flywheel, check the points and look for a sheared pin.
If its not that, it's the Carb.
 
Back
Top