What spark plugs for a ‘66 273 Commando?

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SSVDP

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I’m not a big fan of Champion spark plugs (not impressed with their quality).
What is a good alternative for a stock 273 Commando?

26A281C2-B9ED-4A7A-91A7-01AD8125CCAF.jpeg
 
I’m not a big fan of Champion spark plugs (not impressed with their quality).
What is a good alternative for a stock 273 Commando?

View attachment 1716008028
Compression? What pistons did you use in your rebuild? I need to screw in a new set but My 10 year old Champions are still working.
 
The egge with stock compression
The egge with stock compression
The N10Y's that came stock are a bit too cold and the 2 barrel N14Y's are too hot. I ran RN12Y's and they are just right. Your compression is around 9.5/1 which is halfway in the middle of the two.
 
Or the cross overs to NGK,Autolite,etc.
Just watch the cross overs. I started out with Autolites crossed over from N10Y Champions. The chart I used was too cold and I chased a rough idle for a long time.
 
Produktfinder

I use always NGK, motorcycle, 2stroke, classic cars, kart and more.
Sometimes you need a cross reference chart from the intermet.
Never disapointed! If the NGK plug fouls, your engine had a problem. Best thing they are cheap too
!
 
Needs to be a 5 heat range in NGK, not 4 [ unless the engine is severely worn & burning oil ].
 
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