Johnson 115 v-4 from 1983 spark plug

[alcfer]

I have a 115 v-4 engine of 1983 and i have 2 questions about the spark plugs:<br /><br />1.- What is the difference between the champion models L77JC4 and QL77JC4?, Both are recommend bu my Clymer manual.<br /><br />2.- In the two models above mentioned, my manual specifies a 0.04 in for gap. I have a new set of QL77JC4 and the gap is aprox 0.03 in.<br /><br />What is the correct gap for this spark plug in my engine?<br /><br />Thanks for your help

 

[OBJ]

Re: Johnson 115 v-4 from 1983 spark plug

Al....<br /><br />Your engine will take a QL77JC4 or a QL82C both set at .030 gap. The "Q" denotes a resistor spark plug recommended for most CD ignitions.

 

[7-up]

Re: Johnson 115 v-4 from 1983 spark plug

Greetings alcfer:<br /><br />"Q" stands for "Q-Series" inductor types (used in Copper Plus & Premium Stainless) and are the only OMC approved replacement plugs for engines specified. Use of other types may cause engine misfire. This is according to Champion themselves. without the Q you would have a standard spark plug.<br /><br />Champion recommends a .030 gap for your engine.<br /><br />Hope this helps. Sounds like you have the correct plug set at the correct gap.<br /><br />Take care in Spain...been there once (Barcelona) loved it!<br /><br />Barry

 

[7-up]

Re: Johnson 115 v-4 from 1983 spark plug

alcfer:<br /><br />p.s.<br /><br />QL77JC4 is the correct plug for your engine, forgot to mention.<br /><br />Barry

 

[DJ]

Re: Johnson 115 v-4 from 1983 spark plug

It will idle better with the gap set at .040"

 

[alcfer]

Re: Johnson 115 v-4 from 1983 spark plug

Many thanks to everybody for your help.<br /><br />Greatings

 

[G DANE]

Re: Johnson 115 v-4 from 1983 spark plug

Did anyone ever try 0.035 ??

 

[walleye052974]

Re: Johnson 115 v-4 from 1983 spark plug

my book says that the gap should be .040

 

[Joe Reeves]

Re: Johnson 115 v-4 from 1983 spark plug

The gap setting or .030 did not come into being until later on in years, approx early 1990s.<br /><br />The correct plug is Champion, either the QL77JC4 or L77JC4 with the gap set to .040 .

 

[Luna Sea]

Re: Johnson 115 v-4 from 1983 spark plug

Interesting post. To think I've been setting the gap for my 85 looper at 1 millimeter all this time...............

 

[hammlfam]

Re: Johnson 115 v-4 from 1983 spark plug

Djohns, you said it would idle better at .40? I have a 94 johnson 120 that just had the carbs rebuilt an when at idle or really slow speeds tends to stall. I just put in new plugs, QL77JC4. Do you think this might be my problem?<br /><br />thanks

 

[Guvner..]

Re: Johnson 115 v-4 from 1983 spark plug

How far back does this advice on spark plugs go? I have a 1978 Evinrude 115 HP that has been rebuilt one time and I think I was told it was 40 over. Any advice and where did you guys go on the spark plug gap? Are we mid 90's at .30 or old days at .40 ????<br /><br />Thanks... Gary

 

[Dhadley]

Re: Johnson 115 v-4 from 1983 spark plug

Guvner, I think youre saying your motor was rebuilt and it was bored .040 over size. Actually it was .044 most likely. <br /><br />I know some people set the gap at .035. Their theory being that as the electrodes "wear" and the gap increases it will not miss from too large a gap. Interesting theory.<br /><br />A lot has to do with fuel and oil quality also.

 

[StillFishin']

Re: Johnson 115 v-4 from 1983 spark plug

I'm still confused about the what the gap should be for the earlier 82-83 V4. I know my OMC manual says .40"(either QL77Jc4 or 77JC4) for my 82 115. I had the impression that OMC had a bullitin in the 90's that changed the .40 to .30 but maybe that was just for the 90's engines and doesn't apply to the 80's and they still should be at .40. <br /><br />Can anyone clarifly this for me and probalby others also. thanks<br /><br />STillFishin'

 

[Joe Reeves]

Re: Johnson 115 v-4 from 1983 spark plug

StillFishin'.... The fact that OMC came out with a bulletin changing the gap from .040 to .030 pertaining to the later engines (somewhere around 1990) does not have any effect on what the earlier engines required. Those engines would still require a .040 setting.<br /><br />I have no idea why OMC dropped the gap at some point around 1990 but I have encountered quite a few engines whereas everything was as it should be but the engine would not idle properly. Changing that .030 gap to .040 cured the problem.

 

[StillFishin']

Re: Johnson 115 v-4 from 1983 spark plug

Thanks, Joe, for the clarification of the .30-.40. So for use old f&^ts that still cling to the early 80's v-4, we still should go by the manual-.40.<br /><br />StillFishin'