Champion Spark Plugs

grima

Cadet
Joined
Jan 24, 2002
Messages
16
Are L77JC4 & QL77JC4 the correct Champion spark plugs for a Johnson 115 (1970 model)?<br /><br />If so, what's the difference between them?
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Champion Spark Plugs

Yes. "Q" denotes a suppressor type plug. <br /><br />Good luck!
 

EatMoreFish

Petty Officer 3rd Class
Joined
Dec 9, 2001
Messages
81
Re: Champion Spark Plugs

Champion spark plugs<br />Back 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.<br />Just my 2 cents
 

Capn Mike

Chief Petty Officer
Joined
Dec 10, 2001
Messages
561
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. <br />Anyone had any experience to chat about?
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
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. <br /><br />Good luck!
 

Capn Mike

Chief Petty Officer
Joined
Dec 10, 2001
Messages
561
Re: Champion Spark Plugs

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

Trent

Captain
Joined
Nov 17, 2001
Messages
3,333
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).
 

EatMoreFish

Petty Officer 3rd Class
Joined
Dec 9, 2001
Messages
81
Re: Champion Spark Plugs

I forget the exact plug .. I will look tonight and see if I can find one<br />On 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 plane<br />Cutting the rockers and rewelding them :) <br />Nitro<br />putting them on 10' boat with basa (sp?) wood stringers and so thin you could see through it with a lighter<br />Racing 1/8 mile +- on the top of dikes at Kissimmie<br />spent more time on dry land than my truck did<br />Spinning 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
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Champion Spark Plugs

Mike -<br />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.<br /><br />Let us know how you make out. Good luck!
 

almost retired again

Chief Petty Officer
Joined
Feb 9, 2002
Messages
438
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 ASS-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.<br />That's my horrow story; take for what it's worth
 
D

DJ

Guest
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.<br /><br />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.
 

Dhadley

Supreme Mariner
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Feb 4, 2001
Messages
16,978
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.<br /><br />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!<br /><br />Good luck!
 

Boo

Seaman Apprentice
Joined
Nov 26, 2000
Messages
46
Re: Champion Spark Plugs

Almost retired again,<br /> Could you explain to me why the NKG's cause <br />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
 

jegervais

Chief Petty Officer
Joined
Jan 18, 2002
Messages
646
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. <br /><br />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.<br /><br />-John
 

Boo

Seaman Apprentice
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Nov 26, 2000
Messages
46
Re: Champion Spark Plugs

Hey John,<br /> Thanks for the information, it's greatly appreciated.
 

G DANE

Commander
Joined
Nov 24, 2001
Messages
2,476
Re: Champion Spark Plugs

Thanks Dhadley and John for this very special information.<br /><br />I experiendes champion spark plugs last longer than NGK i smaller crossflow motors, probably realted to their better function.
 

almost retired again

Chief Petty Officer
Joined
Feb 9, 2002
Messages
438
Re: Champion Spark Plugs

Hi Boo<br />John from Illinois pretty well answered your question about radio frequency interferance (or noise).I personally think it was activiting the SCRs (silicone control rectifiers) in the power pack cousing the engine to basicaly fire when ever it wanted to, or whenever they got a spike of rf voltage.
 

petryshyn

Commander
Joined
Oct 3, 2001
Messages
2,851
Re: Champion Spark Plugs

Hi gents<br /><br />The whole idea behind resistor plugs is to add resistance into the secondary (high voltage) circuit. This increase in resistance reduces current flow through the coil secondary winding, plug, and wire. The reduction in current results in less magnetic fields being produced. These magnetic feilds (EMI) produce radio noise (RFI). Manufacturers also add resistance in the circuit by using TVRS plug wires (resistor wires) and some even add further resistance in the distributor button that the rotor rides on. Since the plug wire acts as the antenna, the shorter the plug-wire, the less the emitted noise. I've seen engines that would not run because of non-resistor wires installed. I'm sure they contributed to some of my grey hair. <br />If you take an ohmmeter and connect from the plug wire terminal to the center electrode, you can measure the amount within the plug. As John from illinois says, I have found that it varies drastically from manufacturer to manufacturer, even though they were both resistor types. In automotives, you can get away with it, because, the wires adds lots (up to 30,000 ohms per wire), the cap button can add another 2000. <br />As almost retired says....it is very concievable that the lower resistance plug allows higher current flows which emit larger magnetic interference. The RFI is picked up on the trigger coils and wires leading to them, resulting in premature firing.<br />A neet example that we do, is hold a soldering gun near a GM HEI distributor, while the engine is running. The soldering gun produces RFI and the distributor pickup receives it and causes misfires.<br /><br />When OEM recommends a plug, all this is taken into consideration. (but what do they know...LOL)<br /><br /> :)
 

PeeWee

Seaman Apprentice
Joined
Jan 18, 2002
Messages
32
Re: Champion Spark Plugs

Dhadley,In no way am I saying your wrong,the only plug I have good luck with, is Bosh. I run them in everything.I have never had good results with champion,(not since the mid 70's).I live in south Texas, could it be the heat?
 
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