Ignition Problems

[M Frey]

I have a 1977 75 HP Evinrude with some ignition problems. The engine is lacking power and if feels like a cylinder or two is droping briefly when trying to plane. At idle it also drops a cylinder or two and sometimes dies.<br /><br />This is what I have done. I have replaced all three ignition coils, the powerpack, and the stator. I have cleaned the carbs and verified fuel flow to each cylinder. Compression is 110,115,115.<br /><br />I have noticed a few things. Spark is jumping from all three spark plug boots (new) to the block and metal portion of the spark plug. Also, the top and bottom spark plugs have noticeable buildup, while the middle spark is very clean. The spark plugs only have about 4 hours on them. The jets in the carbs are fixed. I've also used dielectric grease to stop the problem with no luck.<br /><br />Any ideas?

 

[Joe Reeves]

Re: Ignition Problems

Matt.... If, when you speak of s/plug build up, you're speaking of the inner electrodes, that could be contributed to carburetor problems or ignition problems. However, from what you've said, you've pretty well eliminated that possibility.... but those are area that might be well worth double checking.<br /><br />If, on the other hand, you're speaking of build up (corrosion etc) on the outer surfaces of the plugs, that would be contributed to water spray from some source.<br /><br />The spark jumping that distance to ground would also indicate a water trail, a perfect path of least resistance. That engine should have Champion spark plugs, either QL77JC4 or L77JC4 plugs, set at .040 . Let us know what you find.

 

[M Frey]

Re: Ignition Problems

Thanks for responding Joe<br /><br />The spark plugs are the QL77JC4. I had them set to .40 like my manual says, but I just set them to .30 because of the spark leakage around the boot. The old plugs had black marks around the ceramic portion of the plugs so I'm thinking that the old plugs where having the same problems.<br /><br />I just can't understand why the spark would jump half an inch to the metal portion of the plug instead of across the gap even at idle.<br /><br />This problem is going to drive me to my grave.

 

[clanton]

Re: Ignition Problems

What kind of sparkplug wire and boot are you using?

 

[M Frey]

Re: Ignition Problems

That is kind of a tough question, but I believe the ignition coil (which came with the wire and boot) were from Napa Marine Parts.<br /><br />Would the stock high tension leads and boots not be good enough? Could the ignition timing be way off?<br /><br />What are the common and maybe not so common reasons for spark jumping from the base of the boot instead of the gap?<br /><br />Thanks,

 

[M Frey]

Re: Ignition Problems

bump

 

[M Frey]

Re: Ignition Problems

bump

 

[Joe Reeves]

Re: Ignition Problems

Matt..... That's got to be a case of faulty boots. I've never heard of such a thing taking place such as what you've described. Check with your local OMC dealership and get a set of proper boots and inner spring terminals.

 

[M Frey]

Re: Ignition Problems

Thanks Joe,<br /><br />I'll give it a try. I wanted to clarify one thing. I actually saw spark jumping from two of the boots, but all three boots had the same black marks on the porcelain below the boot. Is a little black in this area normal?

 

[ajyanka]

Re: Ignition Problems

Matt,<br /><br />You might try cleaning the porcelain insulator of your plugs REAL good. I’ve had ignition problems because of just general crud on the outside of the plugs.<br /><br />I’m pretty sure there shouldn’t be anything on the insulator. (black marks and such)<br /><br />Good luck!<br /><br />AJY

 

[clanton]

Re: Ignition Problems

Are you sticking the sharp end of the wire connector into the sparkplug wire, before you install the boot? Timing should not cause this.

 

[M Frey]

Re: Ignition Problems

AJY,<br /><br />The plugs are clean except for the burn marks from the arcing.<br /><br />Clayton,<br /><br />I did make sure the sharp end of the spring clip was touching the metal wire inside the spark plug wire. After I inserted the sharp end of the clip I checked for continuity with an ohm meter.<br /><br />Unfortunately I just sold my truck and the truck I ordered hasn't arrived so there won't be any trips to the lake for about a week. I did, however, cut back part of the boot so that there is about an inch between the boot and the metal portion of the spark plug. I ran the engine in the driveway several times, and I never dropped a cylinder and never saw any spark. <br /><br />Is it possible that the boots were too long or I had pushed them too far onto the spark plug?

 

[Hooty]

Re: Ignition Problems

You probably know this and I misunderstood but those burn marks on the plugs is where the spark is leaking to. I'd put new plugs in.<br /><br />c/6<br /><br />Hooty

 

[gerke]

Re: Ignition Problems

he matt<br /><br />i have a simular problem with my johnson 6 hp seahorse , and i would like to know what the solution to your problem whas , if there whas a solution ????