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Evinrude 15hp no start.

hcccs

hcccs

Member
I have problems starting my Evinrude 15hp which I purchased a couple of weeks ago. The seller started it and I have run it once and after that it's impossible to start so I have tried to eliminate one thing after another. I overhauled the carburetor with new float and gaskets, new plugs, new transparent fuel hose from the inlet to the fuel pump. I can see fuel coming all the way to the fuel pump but I can't tell if there's any gas coming to the carburetor. It refuses to ignite even though I tried with some start spray. I tried several minutes with and without choke to no avail. I removed the plugs and they are bone dry so no gas into the cylinders as it seems. So what is next - take the fuel pump apart and inspect. The seller said he replaced it but who knows.
 
Does spark jump a gap of 3/8" on both leads , yes or no ?----Put 5 drops of fuel in each sparkplug hole.----Install plugs and try and start it.----Report what happens.----Are you sure choke is closing ?-----Are you turning throttle grip all the way against the neutral interlock ?
 
I tested before turning the flywheel with a drill at low speed with a socket and the sparks were 3-4 mm, not more. Turning the throttle to "neutral interlock" is that idle or full? I will test to start with the fuel drops tomorrow.
 
racerone said:
Does spark jump a gap of 3/8" on both leads , yes or no ?----Put 5 drops of fuel in each sparkplug hole.----Install plugs and try and start it.----Report what happens.----Are you sure choke is closing ?-----Are you turning throttle grip all the way against the neutral interlock ?
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Does spark jump a gap of 3/8" on both leads? No, just 3-4 mm
Put drops of gas in plug holes, even a shower of start gas. Won't ignite.
Choke is closing. I can see the arm when I pull it.
There is a strange thing with the gas supply. I put in a new inline fuel filter (pic 1) and it is only half filled however hard I pump fuel (new fuel hose and ball). On pic 2 the fuel reached up to the arrow and then there's a bubble of air up to the fuel pump. Normally you don't see where the fuel is, you just pump and start the engine. Now I can see where the fuel is and it doesn't get as far as the fuel pump. How could it when there's air blocking the way? Could it be something wrong with the fuel pump. Previous owner said he had replaced it.

eng1.jpg
eng2.jpg
 
racerone said:
Does spark jump a gap of 3/8" on both leads , yes or no ?----Put 5 drops of fuel in each sparkplug hole.----Install plugs and try and start it.----Report what happens.----Are you sure choke is closing ?-----Are you turning throttle grip all the way against the neutral interlock ?
Click to expand...
Should spark jump 3/8" when pulling the rope? If it doesn't, does it mean that the ignition modules have degraded?
 
It should ( fuel in cylinders ) bark and roar like a lion for a second or so.----Spark on a good system will jump a gap of 3/8" or more when pulling on the recoil.----Or wrap an old time cord around flywheel and pull it over that way.----Perhaps the flywheel key is sheared and spark is way out of time.----Post the ohm readings you get on charge coil and sensor coil.
 
The flywheel key is OK or the flywheel won't set into the right position for the nut.
The charge coil measured 550 ohms and sensor coil 38 ohms.
I have tried to find info on how to test the power pack but couldn't find any. How do I know the power pack is OK.
 
OK, installed a new powerpack CD 582452 and the sparks jump 3/8". I was standing in sunshine but the sparks were visible although they were rather thin. I also rechecked the flywheel to asure that the key comes into its slot and it does. I pumped gas up to the filter and even used some start spray and I thought it ignited once but that was all. It is DEAD. Is there anything at all that can be checked. I haven't checked for blockage in the fuel filter but I will do that next.
 
I removed and disassembled the fuel pump and it looked fine. I saw a hole at the back of it and another in the mating surface of the block. Something moves the diafragm in the pump, so is it a piece of rod or the engine compression that is routed through this hole? If the pump doesn't work properly, could that explain why the spark plugs are dry?
 
The fuel pump is elegantly simple and reliable on these motors.----The pump is operated by crankcase PRESSURE pulses.----No rod of any kind needed.----Fuel pump has nothing to do with the motor starting either.----Pump is needed to keep carburetor full once motor starts.
 
Thanks racerone
Tested the plugs again for sparks. Watch the video clip. I think the spark looks good enough but I also know that plugs can produce good sparks in free air. When they come under cylinder pressure they may not. The next thing is the spark plug wires. I've already measured them to near zero ohms. I'm thinking of getting new ones. Is that a good idea or clutching at straws?

 
Your video title says NGK spark test. While there is always a plug cross reference, my experience is Johnson/Evinrude engines run best with Champion spark plugs. I would suggest running Champion QL77JC4 spark plugs in this engine.

Just grounding the plug electrode to the block is not a proper spark test. As Racer mentioned, the spark on a Johnson/Evinrude should be able to jump a 3/8" gap. If it cannot, it means you have a weak ignition component. Using a simple Air Gap Spark Tester is a tried and true diagnostic tool on these engines. If your plug wires read 0 ohms, then it means they are good.
 
kevinj said:
Your video title says NGK spark test. While there is always a plug cross reference, my experience is Johnson/Evinrude engines run best with Champion spark plugs. I would suggest running Champion QL77JC4 spark plugs in this engine.

Just grounding the plug electrode to the block is not a proper spark test. As Racer mentioned, the spark on a Johnson/Evinrude should be able to jump a 3/8" gap. If it cannot, it means you have a weak ignition component. Using a simple Air Gap Spark Tester is a tried and true diagnostic tool on these engines. If your plug wires read 0 ohms, then it means they are good.
Click to expand...
I bought a spark tester and while I was spinning the flywheel wathcing the spark gap I discovered a big, fat spark going from the ignition cable boot to the block. I guess it means new set of ignition wires.

 
kevinj said:
Just grounding the plug electrode to If your plug wires read 0 ohms, then it means they are good.
Click to expand...
i’m not sure I agree with that. I was working on an early 70s 6 hp that had poor
spark. Testing with an ohm metre showed no resistance in the cable..
After eliminating everything else by a troubleshooting, racer suggested and gave me new cables.
That cured the issue. I cut apart the old cable with a razor knife, and discovered quite a lot of internal corrosion. Zero resistance can be shown by only a single strand of wire being complete from end to end..
 
I finally purchased new ignition cables and with the spark tester I get good solid sparks 3/8" long so that was perhaps part of the problem. I have replaced the fuel line both inlet-to-fuel pump and fuel pump-to-carburetor with transparent hoses so I can see how far the fuel gets when I press the bulb. It will not get past the fuel pump. I have taken the pump apart and checked it, reassembled it and I couldn't see anything wrong. I followed a descriptin on YouTube to make sure I got things right back again and a final test was to blow on the inlet and you should hear a beeping sound. There's a fuel filter between the inlet and fuel pump (Photo) and I don't know if should be there at all since there's already a screen in the pump. I suspect the previous owner put it there and it is always half filled with air. Could that air bubble prevent the fuel to be pressed past the fuel pump?

ev2.jpg
 
Fuel and air bubbles should easily go through the pump.-----So something is wrong with the way pump was assembled.-----These pumps are elegantly simple in my opinion,.-----But a novice can be confused by how they work.
 
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