Ultimate which spark plug thread

[Sark]

Ok let's hear it what are your favorite plugs for a specific engine. I'm still trying to understand plugs. I see for my.ruppster, some say champion j-8c or rj17lm rj 19lm etc... j8 c has been problematic compared to others.

My briggs 3 up also runs better on rj17lm. And if anyone has the patience what's the difference from rj19lm???

And if you say search function!!! I have combed this site. Literally. Should be a sticky!!

Anyway would be a good reference!

 

[Fantic Freddy]

For my 2 stroke '70 Broncco TX7, Bosch works the best, for my American flatheads, its Champion.

 

[creia]

For (unmodified) Briggs and Tecumseh engines NGK BM6Y. Years ago Champion plugs "used to be" the gold standard- not any more. About 8 years ago My son and I started getting Champion "duds" brand new out of the box. We went to NGK and never looked back (and never got another dud). Just take a look at what brand plugs most small engine repair shops and motorcycle repair shops used = NGK. That tells you something right there.
Michael

 

[diveinhollow]

I have tried several spark plugs one of most effective while racing I would choose denso

Sent from my LG-H830 using Tapatalk

 

[Oldschoolcool]

Sark, the RJ19LM is the next step hotter plug from the RJ17LM.

 

[Tom S.]

I make my purchase decision based on how attractive I find the manufacturer's logo/decal. That's as rational a means as any other. NGK's and Champion's logos are both iconic, so I use each brand - NGK in my Japanese motorcycles and Champion in my minis.

 

[San Diego]

For Briggs 5 HP flatheads:

NGK BU8H. Surface gap, so you don't have to index the plug to face the right way. Click on the plug pic for a larger view in this link:

Your Parts Search Returned 1 Part(s)

A lot of kart racers use this plug.

 

[capguncowboy]

For Briggs 5 HP flatheads:

NGK BU8H. Surface gap, so you don't have to index the plug to face the right way. Click on the plug pic for a larger view in this link:

Your Parts Search Returned 1 Part(s)

A lot of kart racers use this plug.

Does that really make a difference? It doesn't seem like it would

 

[Sark]

Thank you creia! I'm looking for specifics which plug model for what motor not just which brand. What works best for say an hs40, a briggs 3hp, 5hp, and a predator.

Thx!!

 

[San Diego]

Does that really make a difference? It doesn't seem like it would

Yes. Every little bit helps, especially when it doesn't cost you much/anything extra.

 

[San Diego]

Predator:

Autolite 3910X

 

[SAS289]

For (unmodified) Briggs and Tecumseh engines NGK BM6Y. Years ago Champion plugs "used to be" the gold standard- not any more. About 8 years ago My son and I started getting Champion "duds" brand new out of the box. We went to NGK and never looked back (and never got another dud). Just take a look at what brand plugs most small engine repair shops and motorcycle repair shops used = NGK. That tells you something right there.
Michael

Years ago I had a new Champion "dud". Was kicking the hell out of my normally 2 kick RM250. Even had someone verify spark while I kicked. Put another plug in it and it started right up. The lesson there was that even though you see a spark, doesn't mean it is a good spark. In this case not good enough to start the 2 stroke engine.

 

[T-Town Mini]

I use E3 spark plugs in all my small engines, now.

E3.22 is used in the Predator.