Sparkplug (spark plug) cross reference guide for Happy Time style engines

Fabian

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Sparkplug (spark plug) cross reference guide for NGK, Bosch, Denso & Champion

Ok, been doing some research as to alternative plugs for the NGK BP*HS series that we seem to commonly use in our Happy Time or China Girl 2-stroke engines.

Cross reference part numbers and equivalents.

NGK BP5HS = Denso W16FP-U or Denso Iridium IWF 16 = Bosch W8B or W8BC or W8BP = Champion L92Y
NGK BP6HS = Denso W20FP-U or Denso Iridium IWF 20 = Bosch W7B or W7BC or W7BP = Champion L87Y
NGK BP7HS = Denso W22FP-U or Denso Iridium IWF 22 = Bosch W5B or W5BC or W5BP = Champion L64Y
NGK BP8HS = Denso W24FP-U or Denso Iridium IWF 24 = Bosch = None......................= Champion L61Y

Unfortunately, neither Denso or NGK manufacture a supplementary gap spark plug (multi pronged) to suit a 12.7mm thread reach.
With NGK, each heat range figure gives 70 degrees celcius (158 degrees fahrenheit) temperature differential at the firing tip, to the next heat range above or below the nominated sparkplug.
So, a BP7HS runs 70 degrees hotter than a BP8HS or 70 degrees cooler than a BP6HS sparkplug.

Now you can go out and play till your hearts content.


Fabian
 
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My unconfirmed notes, feedback appreciated....\


Spark plug gap .22-.25
NGK B6HS & B5HS
Champion L86C
Champion CJ7Y low profile ( I like these)
Autolite 425
ND W2OFS_U
Bosch W9EO
Diamond Fire E3.12
 
What was your impression of the Diamond Fire E3.12 spark plug.
It's the closest thing available to a supplementary gap (multi pronged) spark plug, which is my preferred option.

Have you tried the projector nose equivalent of the NGK B*HS series, being the BP*HS

Fabian
 
I put an E3.10 in my HT engine. It starts easier and runs wonderfully.
I have not put many miles on it though, as the dilapidated bicycle is not up to the task.
I cannot give you long term results.
 
After breaking the stock plug trying to remove it.I went with the Champion L86c plug. It has been in there several hundred mile no problems, quick starts. Napa also also crossed a Autolite plug 425. will try it next...I also use AMSOIL Interceptor oil a synthetic blend 10 oz to 2 gal... Very smooth running motor..
 

Dave, I'm sorry, I forgot? Probably other chat blogs. I opened up microsoft word and started dumping other peoples notes (copy,cut,paste) to it.

I've assembled a serious collection of info on our 2strks, have it in word format but can't post it here due to size constaint of the board. PM me your regular e-mail adress if as a MOD, you can post it! Would be of value to others!
 
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