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Champion Spark Plugs

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  • Champion Spark Plugs

    Are L77JC4 & QL77JC4 the correct Champion spark plugs for a Johnson 115 (1970 model)?If so, what's the difference between them?


  • #2
    Re: Champion Spark Plugs

    Yes. "Q" denotes a suppressor type plug. Good luck!

    Comment



    • #3
      Re: Champion Spark Plugs

      Champion spark plugsBack in my airboat days, I had a 0470 continental aircraft motor (220 hp 470 ci 6 cylinder). After putting in dome pistons in it (maybe a few other things), every time I would open it up it would blow the porcelain right out of the Champion spark plugs. Other types seemed fine (ie AC) but the Champion spark plugs seemed weak so now I never use them in anything. But at that point we were not talking pump gas anymore also.Just my 2 cents

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      • #4
        Re: Champion Spark Plugs

        Hmmm....I was just going to post a question about Champion spark plugs. I have a 200 hp Johnson, which came with Champions, but have been told by several people, that NKG are far superior. Bought 6, will put them in this weekend. Had an auto parts guy tell me Bosch were just as good. Anyone had any experience to chat about?

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        • #5
          Re: Champion Spark Plugs

          We have done a lot of testing and research along these lines through the years and can tell you this -- stick with Champions in an OMC (carb) motor. Good luck!

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          • #6
            Re: Champion Spark Plugs

            Dhadley, mind telling me a little more about who "we" is? Repair shop, dealer, or some such? Thanks!

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            • #7
              Re: Champion Spark Plugs

              Eatmorefish...Were you using aviation sparkplugs?? Iv never seen one do that in over twenty-five years. Use Champion plugs everyday in aircraft (They are the #1 maker of aircraft plugs and oil filters).

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              • #8
                Re: Champion Spark Plugs

                I forget the exact plug .. I will look tonight and see if I can find oneOn the airboats we would remove the aircraft wires ect and use racing type auto ones it was cheaper. We had compression so high that sometimes it would diesel on the better fuels. We would do all kinds of things that you would not on a planeCutting the rockers and rewelding them Nitroputting them on 10' boat with basa (sp?) wood stringers and so thin you could see through it with a lighterRacing 1/8 mile +- on the top of dikes at Kissimmiespent more time on dry land than my truck didSpinning those big props till they screamed. Tried to keep it under 3200 (that is screaming for aircraft) but somedays it went beyond that. I know one go that was *****ing about losing the tips on his props. He was spining them at 4800 +- I would hide when he ran his boat

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                • #9
                  Re: Champion Spark Plugs

                  Franky guys on a stock motor it should not matter

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                  • #10
                    Re: Champion Spark Plugs

                    Mike -I ran the outboard remanufacturing division of a marine engine company for 20 years and we did all sorts of independent testing for other companies. I now have my own company and do testing and consulting for several manufacturers. One of them manufacturers pistons and they are particulary interested in the relationship between spark plugs (correct and incorrect), todays fuel and pistons. It's an ongoing learning experience.Let us know how you make out. Good luck!

                    Comment



                    • #11
                      Re: Champion Spark Plugs

                      For what it's worth I worked most of one day chasing my tail on a Johnson 200. It had a brand new set of NGK's so I ***-U-MEd that couldn't possibly be the problem with an engine that it wouldn't even attempt to get on plane. I tried everthing even changing all ignition parts with new the sympthon still kept pointing to the plugs, so finaly I changed those brand new NGK's. walla problem solved. After changing back all those new parts you can bet that I've always used what the factory recommended. What it turned out was those NGK's put out so much RF noise that it was interfering with the pack.That's my horrow story; take for what it's worth

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                      • #12
                        Re: Champion Spark Plugs

                        It has been my experience that Champion makes a decent "general" plug. They make them for everything. Whether or not they're the best fit for every machine on the planet is another story.I agrtee with dhadley, if the engine came with them ,stick with them. Otherwise, use what the engine came with. Imports seem the most sensative to this, whether they be marine engines or automotive applications.

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                        • #13
                          Re: Champion Spark Plugs

                          Absolutely Djohns19 -- to expand a little further on what we found, I wouldn't dream of recommending a Champion plug for some engine that was meant to use something else. The Merc / Yamaha / NGK combination comes to mind.I must also point out we are talking about stock recreational motors. We have indeed used NGK plugs in an OMC but it was a race motor dumping tremoundous amounts of fuel and turning 9000+ RPM. A far cry from stock. Ah, the good ol days!Good luck!

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                          • #14
                            Re: Champion Spark Plugs

                            Almost retired again, Could you explain to me why the NKG's cause this RF noise to the pack(s) and are they the only plug that can do this to a outboard motor? what exactly is RF noise? Thanks

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                            • #15
                              Re: Champion Spark Plugs

                              ANY non-suppressor spark plug can "cause" RFI. The plugs don't actually cause the RFI, the ignition coil does. Almost all of the OMC-built cd-ignition systems require a "Q" style Champion plug, Q designates Suppressor-Resistor. The NGK plugs, although they are a resistor-type, don't offer the suppression feature the Evinrudes and Johnsons require. Here's my understanding: When the voltage (250v) that is stored in the charge capacitor (internal component of powerpack) is released, it travels via the primary wire to the primary winding of the ignition coil. The voltage flowing thru the primary winding creates an electro-magnetic force which acts on the coil secondary windings and this basically act as a step-up transformer and boosts the voltage to 25-35kv (depending on application). As the voltage spikes and falls, RFI (radio frequency interference) is created. The suppressor plugs "absorb" this spike. If the RFI isn't dealt with, the energy from it can interfere with the operation of the ignition system, due to the close proximity of all the components. It can cause a hi-speed miss or make the engine go into SLOW.-John

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