1972 JOHNSON 125HP SPARK PLUG

[LOSTBOATER72]

Help!<br /><br />I have a low hour 72 johnson listed above. I am trying to locate the correct spark plus for the motor but nobody carries the Chamption L77V the original manual it calls for. I have tried a NGK but it has an electrode which the original plugs to do, they have a surface spark. Please help as I am currently running Autolites with surface spark but they are only getting my outboard up to 4k rpm and it was running at 5.5k with the electrode but I know these are the wrong plugs. Any help would be greatly appreciated. Thank you.!<br /><br />Lost in Sacramento, CA<br />Folsom Lake is finally Full and I can't reach top speed!!!

 

[Spidybot]

Re: 1972 JOHNSON 125HP SPARK PLUG

I'm afraid I do not understand your question <br />

I have tried a NGK but it has an electrode which the original plugs to do, they have a surface spark

NGK recommends B7HS (which looks ordinary)or their Plantinum B7HVX (which has different looking electrodes). Why not go for one of these?

 

[Joe Reeves]

Re: 1972 JOHNSON 125HP SPARK PLUG

You can use the alternative Champion L77JC4 plug which has an electrode. Set the gap to .030 . If your engine doesn't perform to the top rated rpm, it would be a good idea to check the compression, spark, carburetors etc.

 

[papasage]

Re: 1972 JOHNSON 125HP SPARK PLUG

that is what i use in my 1972 50hp . and a1974 . had a 115 hp and that is what i used l77jc4. these plugs are recomended if you do a lot of idling or a fowling probablem .papasage>>>>>>>>>>>>>

 

[LOSTBOATER72]

Re: 1972 JOHNSON 125HP SPARK PLUG

The original plugs do not have any electrode. I have cross refenced the NGK B7HS but the electrode protrude into the cylinder too far and one in particular hits the very top of one of the pistons(ouch!!!). I need a surface spark plug for this engine and nobody seems to know the right one to get. <br /><br />L77V CROSS REFS A BUHW IN THE NEWEST NGK CROSS REF GUIDE BUT NOT SURE IF THIS IS THE BEST PUG FOR MY ENGINE. PLEASE HELP!!!<br /><br />LOSTBOATER72

 

[Hooty]

Re: 1972 JOHNSON 125HP SPARK PLUG

The manufacturer (OMC) specifies Champion sparkplugs for that engine. Mr. Reeves said use Champion L77JC4's gapped at .030". That's the hot ticket.<br /><br />c/6<br /><br />Hooty

 

[LOSTBOATER72]

Re: 1972 JOHNSON 125HP SPARK PLUG

All,<br /><br />I have a question, is the L77JC4 THE SAME AS THE QL77JC4??? IF NO COULD I GO WITH THE SM264D SPLITFIRE TO GET A LITTLE MORE HP. CAN'T STAND DOING 25-30 MPH GETTING PASSED BY BAYLINERS WHEN MY GLASTRON CAN DO CIRCLES AROUND THESE BOATS NORMALLY AT 40-45MPH. PLEASE LET ME KNOW ASAP AND I WILL ORDER. I CAN'T WAIT TO GET UP TO SPEED AGAIN. <br /><br />LOSTBOATER72- SACRAMENTO, CA FOLSOM LAKE HERE I COME!!!

 

[ob]

Re: 1972 JOHNSON 125HP SPARK PLUG

Splitfires ain't gonna do nothin but split your wallet open.I'll be the third to recommend as Joe stated and say use the Champion L77JC4's gapped at.030".If your motor is not getting up in RPMs ,your problem isn't going to be solved with a hyped super plug.

 

[DJ]

Re: 1972 JOHNSON 125HP SPARK PLUG

Ditto, OB. L77JC4<br /><br />If your engine is not getting the power it should, look elsewhere. Might I suggest a clogged high spped carbureter jet?<br /><br />Better get that fixed or you will melt down a cylinder.

 

[Spidybot]

Re: 1972 JOHNSON 125HP SPARK PLUG

Ah, now I get it too. If there's actualy no room for an electrode... <br /><br />Weird that NGK recommends those.<br /><br />The advice is obvious and djohns conclusion holds the truth.

 

[Joe Reeves]

Re: 1972 JOHNSON 125HP SPARK PLUG

LostBoater.... The difference between a Champion QL77JC4 and a L77JC4 plug is that the "Q" is a resistor plug that helps quiet ignition noise etc in your electronic equipment.<br /><br />You mention that one of your pistons would hit the electrode of the spark plug. If it hits the electrode of either of the s/plugs mentioned above, it's not the fault of the plug. The cause would be an internal problem within your engine, such as a worn wrist pin of con rod bearing, or the piston has set up pre-ignition and is melting, that sort of thing.