Spark plug?

[89stratus279]

I have got a 1989 Johnson 150 GT on a Stratos 279FS I just purchased. I am currently rebuilding the boat, however I have done some reading on the website and a little bit of studying elsewhere and the pulg that is suggested is a QL77JC4, right now the motor has got L76V's in it. Champion's website says the The L76V series plug is a plug used in racing application, helps from predetination, keeps plug from burning up if there are problems like low octane and some other things. Everybody on this website with this engine says to only run QL77JC4 plugs. All I have done so far is start the engine, determined it is not pumping water, notice the carbs are leaking gas around the bowl, and taken it off the boat. I plan on fixing all those things but I seen the spark plugs were not what it called for. What do you guys think, maybe who had it before me had some ignition problem or fuel problems that is why the change in plug?

 

[tashasdaddy]

Re: Spark plug?

the chart says Ql77JC4, http://www.boatsetup.com/Spark Plug Chart 2007 BRP.pdf

 

[89stratus279]

Re: Spark plug?

I am going to put the QL77JC4's in the engine, just curios if anybody would know if there may be a reason the previous owner would use this other plug.
I read down the forum a ways and read the discussion about the same plugs in question in another situation, sorry to be beating a dead horse here. Was just wondering if there could be something I could check out while I got it on the stand. Thanks.......

 

[EN2]

Re: Spark plug?

The L76V is surface gap plug, used for constant high speed running. The QL77JC4 is a plug used for all running conditions. Surface gap plugs have a center electrode firing 360 degrees around the plug shell,firing at anyone point around it. It is also a plug with no heat range. The QL77JC4 has a heat range and is used as an alternate for most varying load applications. This plug looks like your normal automotive spark plug with the ground electrode.

 

[tashasdaddy]

Re: Spark plug?

surface gapped plugs also known for fouling easily.