hottest Champion plug

[StriperChaser]

Which is the hotter Champion plug, QL82C or QL77JC4 ? I just left a Johnson dealer that sold me the QL77JC4 saying it was the hottest, but looking at the Champion Heat Range Charts, looks like the QL82C runs hotter. I told him the heat chart seemed to show the opposite, but he was so sure of himself he didn't need to look at any documentation.

 

[Dhadley]

Re: hottest Champion plug

The 82 runs hotter. That's why you are better off with the 77's. <br /><br />You forgot to mention what motor you have. And why you need a hotter plug.<br /><br />Let us know!

 

[StriperChaser]

Re: hottest Champion plug

I'm having a problem with the plugs fouling which I believe is due to a build up of old fuel with too much oil in a 96 Johnson 112 SPL. I'll be doing a lot of trolling this summer and want to use the hotter of the two plugs for idling/trolling. Or do I have it backwards, cooler plug for idle and hotter plug for WOT, maybe I'm wrong.

 

[Dhadley]

Re: hottest Champion plug

Start over with fresh 87 octane and the 77's. When all is correct that crossflow will idle for hours. Old fuel equals higher combustion temps which is bad. Pistons don't like it. Hotter plugs equals higher combustion temps too. Put the two together under a load and your pistons just might revolt. Even at idle the motor will coke up quickly.<br /><br />Good luck!

 

[seahorse5]

Re: hottest Champion plug

The '82 is the factory recommended plug and is slightly hotter than the '77s, but there is a QL86C that is even hotter and is used on smaller hp motors. From you earlier posts, I doubt that plugs will solve your problems.

 

[StriperChaser]

Re: hottest Champion plug

Thanks for the advice. I finally managed to siphon out about 25 gallons of fuel and installed the QL82C. I've always run Premium 93 Octane, but have been told several times to use 87 in this series of posts. Should I not be running 93 ?

 

[DJ]

Re: hottest Champion plug

StriperChaser,<br /><br />You DO NOT need 93 octane. 93 runs cooler (thus nulling the effect of your hotter plugs) which tends to carbon up rings.

 

[StriperChaser]

Re: hottest Champion plug

Well since I finally emptied the tank, I'll run through some 87 Octane and see how it does. I just thought the 93 would burn cleaner. It sure does much better in 4 cycle auto engines. I've managed a fleet of vans and pickups for years using only 91 to 93 octane and have had minimal need for unscheduled tune ups and injector cleaning which I believe is directly related to the premium fuel. Never thought outboards would be any different.

 

[DJ]

Re: hottest Champion plug

StriperChaser,<br /><br />I would even tend to disagreee with you on the "premium" fuels for automotive-unless the the OEM calls for it-which are few.<br /><br />High octane in an engine that does not require it, tends to turn an engine into what we call in my business, "an octane junkie".<br /><br />The cooler/slower (read premium) burning fuels leave deposits in the combustion chambers which tend to glow. If someone tries to switch back to the recommended fuel, the engine will detonate (spark knock) from the glowing deposits in the combustion chambers. The condition builds on itself until even some of the premiums detonate.<br /><br />Also, not to mention what an extra $0.10 t0 $0.15 cents a gallon does to an operating budget.<br /><br />If the engine does not require it, I do not recommend it. And I'm the guy that pays the warranty bills.<br /><br />By the way, I would recommend that you do a decarb. on your engine if you have never done one. Certainly won't hurt and might just save some headaches down the road.<br /><br />Let us know when you "catch" some of those Stripers!

 

[FlyBoyMark]

Re: hottest Champion plug

djohns has it rite...................I've known this for years........higher octane unless you need it is loaded with additves that clog up low compression engines, not to mention the carbs.....lower octane fuel burns much cleaner. The only reason for high octane is to prevent preignition in high compression engines....................

 

[Boatist]

Re: hottest Champion plug

There is also a L90C plug. I have been useing them for years in a 15 HP Johnson 2 stroke, but I only troll with the motor.<br />Seen several post that say to use 89 midgrade but none that use alchol like AM/PM Arco. One guy who is suppose to know sweres has one additive that stops carbon build up. He also says do not use 93. As far as the cars and trucks I use nothing but 87 and have not had a car that did not make 250,000. All I do is change the oil every 5000, timing belt every 100,000 and Coolent every 2 years.

 

[StriperChaser]

Re: hottest Champion plug

So am I going to have a problem switching back to 87 octane with the outboard? Thanks for all the imput. <br /><br />www.StriperChaser.com

 

[Dhadley]

Re: hottest Champion plug

You will have no problem going to 87. Actually the 93 of today runs hotter than 87. Thats because of all the additives they add since we lost the lead. They are oxygen bearing which increases combustion temps. It has gotten somewhat better since they got rid of the MTBE.<br /><br />This is not to say you CANT run 93. I run it in one of my 225's but its a high compression motor which needs more octane. And the carbs are jetted up to bring the combustion temps back down. <br /><br />Good luck!