Intermittent spark 1973 Evinrude 6HP Fisherman

Motor: 1973 Evinrude 6HP Fisherman

Hello everyone. I have viewed many posts and threads on this forum over the past few years that truly helped me along the way, but now I've run into an issue that I am working to resolve but could use some insight.

To begin, I rebuilt a boat motor and replaced points and condensers. (First motor I've ever rebuilt) I honed the cylinders and replaced a piston. I set the points and had a great running motor for over a year all with the help of this forum. Well, when I put the coils back on, I didn't have a retaining ring to set them and eyeballed it. While on the lake it started missing and went out. One of the ends of the top coil was hitting the magnet and it blew up the coil.

Fast-forward to the issues I am havng now.

1) Spark is intermittent at 1/16 inch gap and will not jump 1/4 inch gap.

2)Motor will usually start, will not run for long. Will restart after couple minutes of downtime does missfire.

I have ensured points are set to .020 at the top.
I have ran new plug wires.
New plugs, gapped to .030
New coils (they are Chinese knock offs) The replacement Johnson/Evinrude Coils are ordered and on the way.
Tested condensors with Fluke true RMS multimeter, they are working properly.

The motor has not ran since the coils were replaced, it ran great prior to the coil incident and installing the Chinese coils.

Does anyone know what the parameters should be for testing the coils? Primary I've got 1.5 Ohms. Secondaries are at 7 kOhms on both coils.

My other question I have is how much of this if any could be caused by the magnet itself hitting the coil? There are visible marks on the magnet where it had rubbed against the coil and I feel like I have narrowed down my spark issue to the coils. But wonder if my initial error not setting the coils properly could be causing the issue. What is the likelihood that both new coils are shot out of the box?

Thank you all in advance.

I don't think the coils are bad, and no it didn't hurt the magnets. Possibly bad plug wires. Check them for continuity (unless you already did while checking secondaries). I'd be looking at breaker points.

Thank you for the reply. I did check continuity of the plug wires and they are both good. I have a new set of points on the way as well, they should be here by Friday, these ones look clean and aren't very old. I do think they are the same set that was on here when I lost the coil though. I don't recall if I changed them out after or not

Have you ever seen an issue where the new points won't fit over the pins? The lower half of the point is on, but the new ones plastic bushing is so tight on the pins they will not go on.

I have seen lots of complaints about Chinesium aftermarket parts. Haven't heard this particular one, but there ya go. Did you get them here at marineengine?

These points I just got from marineengine. They are evinrude/Johnson replacement parts.

I'm not connected with marineengine, so can't speak for them. Give them a call.

I've got it down to the point for the top plug is not opening when the cam comes around and there is no more room for adjustment. New points are on, I've also put on new cam screws for the stationary point. I wonder if the point is just faulty or if the cam on the crankshaft may need replaced. More inclined to believe its the point than the came, since the bottom works appropriately.

I'm no expert by any means, and am not representing myself as such.....just an old retired guy that has fooled around with many old outboard motors....and as luck would have it, I have two (2) 6 hp Fisherman, one is a 73 and the 2nd a 74....here's my two cents worth.

First, I've traveled the same road you're on....very frustrating.....I ended up ditching ALL the Chinese parts and going with OEM....everything fit and lined up correctly.

It is CRITICAL that the points line up exactly right....you may have to bend them slightly to ensure you have proper alignment, but BE CAREFUL.

On the plug wires....are you certain the terminations are pushed/screwed into the conductor itself? If you miss this and land in the insulation of the plug wire, you're asking for intermittent fire. Also, make sure you haven't inadvertently crimped/knicked the wires during installation/removal...look at all places where the wire passes thru guides as well as the magneto plate itself.

Double check your coil wiring....is there any way the coil(s) can get grounded (i.e., metal crimps touching metal plate, etc...)? Be sure these wires are wisely routed and secured against vibration and movement.

Finally, I'd go ahead and do a compression check, just to rule that out of the equation.

Good Luck!

Its running now. After bending that point and setting the gap to .020 at the widest point, it starts very easy and it runs. It still doesn't seem to run very smooth. I think something is still not right with it. But it is running.

I have tested compression 75 both top and bottom.
New points
New plugs
New wires
New Condensers
New Coils
Rebuilt the Carburetor
New fuel pump
Rebuilt the motor, honed cylinders, replaced a piston

Maybe I need to adjust the throttle?

It starts very easily, just does not seem to react much when given throttle. Its also still jerky every so often. It makes me think that it is misfiring, but nothing like what it was doing before. Ill have to get it running and put a spark tester (light) on it while its running.

Did you use copper core plug wires and are they twisted all the way into the coils? Did you flatten the mating surface on the float bowl? Make sure that little donut seal at base of bowl is making a perfect seal on the high speed nozzle base.....otherwise unmetered fuel can enter the carb throat. Make sure points are lubed both at pivot post and cam follower. Ask if you need details. Many forget that the pivot post needs a tiny dab of high quality grease or syn. oil. Wear here, over many years, can lead to an inaccurate point gap.

Back the cam screws out one turn and then set point gap.-----Is the HIGH SPEED orifice plug clean ?---It is found screwed horizontally into the bottom of the float bowl.

So I got back to the motor today. It is sparking great everytime. So I took the carburetor off to check it out. Some of the gaskets were already deteriorating im thinking there must be something in my fuel for them to look the way that do. I'll have to get a new kit, clean it all up again and go from there. The high speed orifice was clean. The packing around the low speed adjustment was completely deteriorated and parts of the bowl gasket were deteriorating. I'll have to get rid of the fuel I have and get new fuel. Does anyone know what could cause that? Maybe an alcohol content or something along those lines?

Yes ethanol can damage these parts. Better check fuel pump too....as well as fuel lines. Anything of rubber and many synthetics, are damaged with ethanol.....especially if motor is stored with residual ethanol fuel.

China carb kit?

Probably okay. Some stuff is gonna work pretty good. Gotta be observant on quality.

Hey everyone, thank you for all of the help and insight so far. The carb gaskets were deteriorating and it was from something to do with the fuel. Just an update on the whole situation:

My spark issue is fixed. Compression is at 75 top and bottom cylinders. Got a new tank of fuel and it is running, but running poor. I took some carb cleaner and began spraying a little around the intake gasket and reed valve gaskets. When I sprayed it on the left side of the motor, she sealed up and starting running beautifully for a short period of time and then back to the running like trash. So what began with the spark issue, was also a carburetor gasket issue (resolved) and I have ordered both gaskets for the reed plate and the intake from Marine Engine. This should resolve my issues and I will update everyone on the outcome once they are installed and I test the motor again.

Again thank you all for your input, it was helpful and much appreciated.

Okay, what often happens with these is the little donut gasket at the bottom of the central nozzle, inside the float bowl, doesn't make a good seal, allowing unmetered fuel into the nozzle. Why or how is that? The replacement gasket is quite thin and the float bowl tabs, where the screws go through, get bent and that doesn't allow the float bowl to push all the way up tightly anymore at the center, where this little donut gasket has to seal. The fix then is to surface the float bowl with some wet or dry paper on a flat table or piece of glass and correct the distortion.

Hey all, I am getting ready to put the powerhead back on, I was hooping to get some input on the proper setup for the mechanical seal from powerhead to the housing. The washer in the bottom I would presume sits with the channel up to allow the spring to ride in it. The spring, the seal, o ring, top washer and top seal. Or does the bottom washer go with the two tits facing up, allowing more pressure to the bottom of the powerhead. I got the parts breakdown from Marine Engine. I ordered the seals and o ring from here as well, but I cannot tell from the diagram the orientation of the bottom washer. It was in with the channel up and the spring inside the channel. Just wanted to make sure it was correct in the first place. Thanks for any input. Its on a 73 6hp fisherman, model 6302S.

The brass cup washer is installed first.----The 2 little bumps facing down.---Those 2 bumps engage the roll pin to turn the seal.------Then the spring.------Then the carbon rotating seal element with a new o-ring in the upper part..-----Then the stator element flat side facing the carbon.---Then a new gasket on top.-----That seal is a brilliant design and installed on the CD ( 6 HP ) for about 25 years.

racerone said:

The brass cup washer is installed first.----The 2 little bumps facing down.---Those 2 bumps engage the roll pin to turn the seal.------Then the spring.------Then the carbon rotating seal element with a new o-ring in the upper part..-----Then the stator element flat side facing the carbon.---Then a new gasket on top.-----That seal is a brilliant design and installed on the CD ( 6 HP ) for about 25 years.

Click to expand...

Thank you, that's the way it came out, just didn't want to do all this work and have any of it backwards.