What Plugs??

[s.wxman]

Over my years of ownership (and moving) I have visited 4 dealers regarding my Evinrude engine. Two have recommended QL78YC plugs and two have recommended QL77JC4 plugs. 1995 E150ELEOM. (60 degree V6 looper.)
Owner's manual says 77. I have an original service manual that says 77. I have a Clymer manual that says 78, unless VRO then 77 (I am still using VRO because it still works).
Two dealers say 77 good. Two dealers say years ago OMC changed recommendation to the 78 plug. I have primarily run the 77 plug without issue that I am aware of.
Anyone know the true recommended plug? What would be the probable benefit of one over the other in general terms?

Thanks
Wxman

 

[boobie]

Re: What Plugs??

The latest plug is the 78's. If it's running good on the 77's, keep on using them.

 

[s.wxman]

Re: What Plugs??

Any idea why the recommendation changed, what issue it addressed? No real problems, but I am not against better.

Thanks

 

[schematic]

Re: What Plugs??

Thats odd....BRP recommends QL82YC not QL78YC

 

[Tim Frank]

Re: What Plugs??

The latest plug is the 78's. If it's running good on the 77's, keep on using them.

+1 ^ gapped at 30 thou.

 

[s.wxman]

Re: What Plugs??

See how the confusion continues. I think I will stick with the 77s and not look back. I am sure there are plenty other things to worry about on an 18 yr old engine.

Thanks

 

[boobie]

Re: What Plugs??

Smart man !!

 

[woody66912]

Re: What Plugs??

Every once and a while we would see a false VRO horn, with the 77s, installed the 78s. That's what tech service would tell us. It had something to do with the early system check gauge.