sparkplug question

[mark mcj]

Hi Guys,
I've two different sources telling me two different things about which plugs to use and which gap to set them at.
I have an 82 60hp Johnson.

One source, is telling me to use Champion L77J4 set at .040
The other is telling me to use Champion QL77JC4 set at .030

I can understand the different "QL" but the gap difference has me going

I just read where the NKGs don't agree with OMCs so I'll yank those back out, just put them in 2 days ago.:facepalm:

 

[Art Bernard]

Re: sparkplug question

Go with the mfg's recomendation. If the plug they recomend isn't available anymore, find out what plug replaced it and use that.

Art

 

[DamianJP]

Re: sparkplug question

Yup stick with the Champions.

I just went threw this with my motor.

QL means its low resistance, inductive suppressor .

And the C was Copper plus.

Basically good to go with either plug.

As far as the gap I dunno my book says L77J4 .040 gap too.
Ill dig around more.

DamianJP

 

[DamianJP]

Re: sparkplug question

Yup seen 3 other posts that say the shift to QL77JC4 also shifted the gap to .030. So far looking like .030.

 

[mark mcj]

Re: sparkplug question

Thanks for the replies!
To Art's reply, that's what is the confusing part.
The Johnson repair manual I have (Ver 1.7) states the L77J4 at .040 and the sticky in the top sercet files says QL77JC4's with the .030
I'll get the L77J4 or it's replacemnt and try the .030 if it doesn't preform as well as it has I'll open the gap to.040 and go from there.

 

[npd4432]

Re: sparkplug question

You can run either plug. The QL as stated is a inductive suppressor. Standard gap on most including your motor is .030 . I have had several OMC looper triples and they have run well with the .030 gap.