Yea, the model is in there..but...they only show NGK plugs. I have a cross-referenced Champion QL78YC. I may have to take it back and try to find a NGK. It really shouldn't be this hard to find a plug gap, though...should it? thanks for trying. Rich
Same gap for both resistor and non-resistor plugs
what's shown should work fine for yours.
No real difference between plugs,
gap is to get the right spark in order to properly ignite fuel/air mix
Unless you have a gapless plug...
CHECK YOUR GAPPING! I called merc to ask them a gapping for NGK plugs on my 2002 9.9 Merc. They told me 35 thousandths. Tried that and the engine ran like crap. After looking more closely on a tiny little sticker on the block, I found that the gap should have 60 thousandths. Just a thought on checking. I have also had a big performance difference in other motors I have owned when switching from Champion to NGK.
Silly question perhaps. I have been running the L78YC in my 99 johnson for over a year now. That is what they had when I bought my boat used. My mechanic said they should have the QL78YC. He explained that they are longer and fire more into the cylinder.
My question though is will there be a difference? Anything that I can notice. I never noticed a problem to begin with. Will there be a benifit?