Spark Plug !

Gulu73

Gulu73

New Member
I'm looking for a good NGK spark plug ! I researched and found that B6HS is good spark plug for 2 stroke chinese engines .. And im worried because i have Z4C spark plug and i matched the Z4C with the NGK B6HS and saw that the NGK is longer than the Z4C ! Does it make damage with my straight head 80cc/66cc engine ?
 
straight at first now slanted there was no power difference and yes it worked fine with straight head put it in and go on your way
 
Gulu73 said:
I'm looking for a good NGK spark plug !
...i matched the Z4C with the NGK B6HS
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The NGK B6HS is the hottest running, good for cold climates.
If you want a cooler plug in summer, go with the NGK B7HS.
If you live in Phoenix, run the NGK B8HS. It's for the hottest ambient temperatures.
 
F_Rod81 said:
I run an NGK iridium plug, if you tighten it too much then it will come in contact with the piston.
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Tighten it too much?
Either a plug is tight or it's useless ;-}

I run the BPR7HIX Iridium plug SickBikeParts sells in my 66cc Skyhawk slant head and my 50cc Skyhawk straight head with no problems.

Nice plugs, but their web site does caution that on some 48cc motors it may make head contact, perhaps the slant head 48cc?
 
KCvale said:
Tighten it too much?
Either a plug is tight or it's useless ;-}

I run the BPR7HIX Iridium plug SickBikeParts sells in my 66cc Skyhawk slant head and my 50cc Skyhawk straight head with no problems.

Nice plugs, but their web site does caution that on some 48cc motors it may make head contact, perhaps the slant head 48cc?
Click to expand...

Look and compare the stock plug to any NGK for our motors and you'll notice that there's about an 1/8'' difference from the seal washer. As a result, if you tighten it too much then the piston @ TDC will tap the gap closed and you won't be able to start. I have had this happen on two different builds, one straight head the other a slant head (both 66cc). Maybe by some occurrence I'm the only one that this has ever happened to.
 
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The "P" in BPR7HIX means projected tip plug, just as the "R" means resistor. If you were to use a BR7HIX I believe it would fit much better. I don't know but this leads me to believe that there'd be a B7HIX non-resistor.

NGK.com - Cross Reference Search Results

I contacted NGK about a BPR9HIX and they don't make one, this is the recommended plug for the Puch head on my BGF Z80. If you substitute whatever number in the part number in the url(change the 9 in br9hix) to whatever heatrange you want it would take you to that page.
 
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so my question is, whats the difference between the ngk B7HS and the BP7HS? Is it just the tip projection then? It wont help at all with the spark will it? Im going to be running a puch hi hi compression head on there.. so maybe not the projected tip?
 
F Rod 81 has experiance that I did not have to gain. I put a NGK BP6HS plug in my slant head motor. I took a marking pen and marked where the electrode was on the insulator so I would KNOW where the installed orientation of the electrode was. I got lucky and I had an installed orientation at about the 1 O'clock position. ( 6 O'clock being the bad position). My motor runs a little bit better. A little bit smoother. A little bit more top end
but, if the electrode would have been in the 4 to 8 O'Clock position? I would have aquired a proper washer to achieve the proper electrode orientation. It is THAT close.
 
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