Frustrating Spark Problem.

[charliegiggles]

Hi,
I have a 1973 Evinrude outboard model 40354d. I'm not sure what is going on however the engine used to start fine.
I recently put in new points, condensor and spark plug wires thinking this would be beneficial as I bought this motor off someone. Compression is good on both cylinders.
My problem when the plugs are removed and I rotate the flywheel and ground the plugs I'm getting a spark.
After I reinstall the plugs it would appear I no longer am getting a spark on either plug. I say this because if I remove and ground them again attempting to turn the flywheel by hand no spark appears.
I'm stumped as to what is going on and am starting to think the coils are shot or I'm blowing the condensor but really don't know for sure.
If I remove the flywheel unscrew the condensors and reassemble everything all of a sudden I start getting a spark again when I manually ground the spark plug.
Not sure if anyone has experienced a similar problem. I made sure the wires going to the condensor are not being grounded which would prevent a spark from happening.
Any help would be appreciated as I don't want to order parts needlessly.
By the way the spark that I've seen when manually grounding the plug and turning the flywheel by hand does not appear to be very substantial.
Thanks for your help again!

 

[F_R]

Re: Frustrating Spark Problem.

If you are saying you are getting a spark by watching for a spark across the spark plug, that is not a spark test. You need to rig up some sort of 1/4" gap and see if it will jump that. Sticking a phillips screwdriver in the spark plug boot and hold it 1/4" away from a head bolt will do. If it won't jump the gap, you need to get back in there and find out what's wrong. Sounds like you've replaced everything but the coils, but that doesn't mean the points are clean and properly adjusted. Could be the coils, I suppose, but can't tell from here. At least check it out with a multimeter.

 

[F_R]

Re: Frustrating Spark Problem.

By the way, the torque on the flywheel nut needs to be 100-105 ft/lbs and the tapers clean and dry when you put it back together or you will have other troubles.

 

[charliegiggles]

Re: Frustrating Spark Problem.

Thanks for the help. I'll try the screwdriver gap trick. I have a multimeter. Do I just check ohms across the green and black wire and if so what kind of reading should I expect?

Thanks I'll make sure I torque it properly.

 

[charliegiggles]

Re: Frustrating Spark Problem.

By the way I gapped the points at .020 as per lobe on crank shaft and as per the manual and verified the spark plug gaps as well.

 

[steelespike]

Re: Frustrating Spark Problem.

It is more difficult for the spark to fire under compression.
The spark should be a nice blue and you should here it snap.Be sure the points are set at .020 at the high point of the cam and the new wires should be solid core (copper)and inserted correctly points are clean.Check the stator plate it should not wobble it may have a ground strap to the
engine block.Be sure it is intact.The condensers seldom fail.Pretty much impossible to blow them.Probably the weakest point of the system is the coils if they are original they are probably weak. They may appear chalky or gummy and usually develope cracks.Coils
are available right here at iboats or a E/J dealer or NAPA auto parts.

 

[charliegiggles]

Re: Frustrating Spark Problem.

Thanks very much. This site and feedback are incredibly helpful!

 

[charliegiggles]

Re: Frustrating Spark Problem.

K tried the screwdriver test and althogh I'm getting a spark across an approximate 1/4" gap it does appear to be consistent. Sometimes I get it and sometimes nothing.

I'll try changing the coils and hope that solves the problem.

 

[JUSTINTIME]

Re: Frustrating Spark Problem.

check ohms
between the coils less than 1 ohm green and black
go from black to spark plug lead u should have at least 1K

 

[charliegiggles]

Re: Frustrating Spark Problem.

Ok thanks! I'll check that out.

 

[F_R]

Re: Frustrating Spark Problem.

Intermittant spark at 1/4" might not be bad. It's awful hard to hold a screwdriver at a consistant distance from the head with the engine flopping around. Are you sure you are even going after the correct problem?

 

[charliegiggles]

Re: Frustrating Spark Problem.

Worked on the motor again last night and it would appear the ground cable between the block and armature plate was not making a proper connection so I'm hoping this is the problem. Thanks for the previous heads up on that.

Keeping my fingers crossed that it will start this time around.

 

[BoatBuoy]

Re: Frustrating Spark Problem.

Just a thought - You said you replaced the sparkplug cables. I hope you didn't use any type of automotive cables. They need to be solid copper core wire, available at outboard dealers and small engine shops.

 

[charliegiggles]

Re: Frustrating Spark Problem.

Yes the cables are solid copper core from a marine store and appear to have the same resistance as my previous, older coroded wires.

 

[charliegiggles]

Re: Frustrating Spark Problem.

Ok this one is embarrasing but I'll ask anyway. The woodroofe key was replaced and broke again when I removed the flywheel. If the flywheel is torqued down properly do you think it migh spin on the crank.

The new woodroofe key looked like it was made of aluminum.

 

[BoatBuoy]

Re: Frustrating Spark Problem.

You really need to get the proper key from a dealer or online. That key locates the flywheel properly, but it's not supposed to keep the flywheel from slipping on the end of the crank. The proper torque, together with the taper, does that. If it slipped, it wasn't cleaned and torqued correctly.

 

[F_R]

Re: Frustrating Spark Problem.

Why did I know that was going to happen? OK, are the key slots battered now? Are the tapers galled? Those are the "other problems" I referred to earlier. Battered keyslots make it nearly impossible to assemble it with the magnets in the flywheel in proper relationship with the points cam. Galled and roughed up tapers make it nearly impossible to ever make it hold again. The tapers on the 40hp flywheel and shaft are a hair different angle, so lapping them is not good either. Let's hope you got lucky.

 

[charliegiggles]

Re: Frustrating Spark Problem.

Well good news if started and ran for a bit. I think it is in need of a serious decarb.

On another note there is gas leaking out of the bottom spark plug. The plug screws in tight but appears not to be in perfect condition.

Is there a sealent I can buy to prevent the gas from leaking out of the spark plug hole?
Thanks again....

 

[iwombat]

Re: Frustrating Spark Problem.

If your keyway is slightly munged you can sometimes get the keys to stay properly with a little red loctite applied in the slot and some luck.

Get the proper key though or you're just due for even more damage down the road.

Stick a rabbit's foot under the cowling for added protection.

 

[steelespike]

Re: Frustrating Spark Problem.

Well good news if started and ran for a bit. I think it is in need of a serious decarb.

On another note there is gas leaking out of the bottom spark plug. The plug screws in tight but appears not to be in perfect condition.

Is there a sealent I can buy to prevent the gas from leaking out of the spark plug hole?
Thanks again....

If the plug is leaking gas it would seem you have 2 problems a poor seal on the plug inspect the hole and(try a new plug).
And 2 poor or no combustion on the lower cylinder.