spark plug question/confusion

[BoatBuoy]

Evinrude 35hp, 1977, model 35753. My owners manual specifies L77JC4 spark plugs, so that's what I wrote on my Christmas list, and that's what my kids got me. After Christmas, I took them to the garage, opened and gapped them, and I'm ready to go. This engine hasn't been run in several years and I know there's more I need to do (lower unit, water pump, etc.). However, when perusing the Champion spark plug web site, they indicate L77JC4 may interfere with CDI ignition, and QL77JC4 is preferred. Now the plugs that are in it, L77JC4, have been in there since JB was a young man and performed very well. Can I use these new plugs, or will they truly interfere with the ignition?

 

[Kiekhaeferscurse]

Re: spark plug question/confusion

Hi BoatBouy<br />I'm not a champion type of guy, but I'm betting its just like NGK number listings, identical plugs but the non risistor type of plug will cause interferance on radios, radar etc etc, up here in Canuck land it is against the law to run a non risistor type of plug, so instead of paying say 3 bucks for a v6 plug you pay 9 bucks instead...seems to me like a crock ....but I could be wrong......and I run the non resistors, Have yet to see a battle ship around me hit the rocks in the fog due to my little outboards sparkplugs

 

[JB]

Re: spark plug question/confusion

Don't I wish! <br /><br />I became a Grandpa in 1977, but thanks anyway, BB.

 

[Joe Reeves]

Re: spark plug question/confusion

Boat.... The L77JC4 plugs, gapped at .040 will be just fine on your engine, and that's OMC's recommendation.<br /><br />The difference between a L77JC4 and a QL77JC4 is that the "Q" indicates a suppressor plug which helps to quiet ignition noise which might interfere with any electronic equipment you might be using such as depth sounders/fish finders, radar, ship to shore, whatever.<br /><br />Feel safe to use either plug gapped at .040 .

 

[R.Johnson]

Re: spark plug question/confusion

Thay Q plug is mostly meant for the engines equipped with VRO. It has to do with sending a wrong signal, or interference with the engine warning system. Use either one.