NGK BR4HS - Iridium or other upgrade?

Pablo

Master Bike Builder & Forum Sponsor
Dec 28, 2007
3,665
6
38
Duvall, WA PNW
www.sickbikeparts.com
My 80cc takes a NGK BR4HS. Currently there is a Chinese cheesebo equivalent plug in there.

I was just wondering if anyone could cross reference the NGK BR4HS to an even "better" plug?
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
237
63
up north now
You can't get much worse than the plugs that come with these from China.
You can't get much better than an NGK.
Bosh platinum maybe....

Anything else is just throwing away money IMHO.
 

Pablo

Master Bike Builder & Forum Sponsor
Dec 28, 2007
3,665
6
38
Duvall, WA PNW
www.sickbikeparts.com
You can't get much worse than the plugs that come with these from China.
You can't get much better than an NGK.
Bosh platinum maybe....

Anything else is just throwing away money IMHO.
Deadly correct.

I can even say that a Bosch Platinum is not better than an NGK.

Anyways I emailed NGK and they responded:
Unfortunately at this time we do not have anything available. With the
1/2" thread reach plugs there are only standard nickel plugs available.
There is an iridium IX series BR6HIX available, but is so much colder
that it will most likely foul out pretty quickly. Thank you.
 

Norman

LORD VADER Moderator
Jan 16, 2008
2,605
2
38
68
pampa texas
Guys
I'm still running the plug that came with the engines kit it starts right up and runs smooth with the nice brown color on its insulator. So find out whats a good one so when the time comes that I have to look for a new plug I won't have to look far and hard.
Norman
 

Pablo

Master Bike Builder & Forum Sponsor
Dec 28, 2007
3,665
6
38
Duvall, WA PNW
www.sickbikeparts.com
I don't think you will go wrong with NGK. My instructions call for BR4HS. You could use this if you have a 70-80CC. Or non-resistor B4HS. OR you could step down one heat range to the B(R)5HS.

BR6HIX - I may try it.......
 

Easy Rider

Santa Cruz Scooter Works
Jan 15, 2008
2,144
4
38
Nor*Cal
I've used NGKs for many years/decades in my jetski, scooters and karts but as of last year I've switched to Autolites. I think NGK went thru a phase where their plugs were easily fouling up and going bad. (But that was 2 years ago) I found a box of B6HS plugs that are at least 10 years old. They are the ones with the gold/yellow coating. I've been using them in my bike. I know they are a colder and longer plug but it works fine and I have a little bit more bottom end.
 

MotorbikeMike

Dealer
Dec 29, 2007
477
1
18
Sacramento
Hi the B6HS is a good plug for MOST of these engines, tho some may lack the clearance above.
In some of these engines, the stock plug does NOT fill all the threads.

2-strokes love colder plugs as long as they do not easily foull out.

Mike
 

Easy Rider

Santa Cruz Scooter Works
Jan 15, 2008
2,144
4
38
Nor*Cal
I checked the dome clearance before I used them and I was surprised how much vacant space there was. It was like the size of an expresso cup.:eek:
 

Norman

LORD VADER Moderator
Jan 16, 2008
2,605
2
38
68
pampa texas
If the plugs threads stick out into the combustion chamber that's not a good thing as hard carbon deposits can tear up the heads threads when you take the plug out for what ever reason you need to take the plug out for. I also if I think of it I'll power wire brush the new plugs threads and a little dab of never seize on the threads and everytime I round trip a plug and have access to a wire wheel and never seize I do this. To clean the plug hole a little spray of carb cleaner but I don't do this unless it looks really nasty.What about the nasty that goes into the cylinder you ask. Well I hope it goes out with the exhaust on the first time it fires as aluminum powder that fine in the never seize will burn and burn clean up and out the pipe it goes. what do yo think is in the good old firecrackers aluminum powder and potassium chlorate and maybe a pinch of flowers of sulfur.
Norman
 
Last edited:

Easy Rider

Santa Cruz Scooter Works
Jan 15, 2008
2,144
4
38
Nor*Cal
Gosh Dag it Norm! You had me worried so I put on my parka & gloves and went into my freezing (55 degree) cold garage to check out my plug. After taking it out, it looked nice with a tanish brown color to it. LOL I have about 100 miles on it only.
It's probably b/c I use a mix of 110VP(1 part) and 92(3 parts) octane gas with Castrol 747 oil.
 

Norman

LORD VADER Moderator
Jan 16, 2008
2,605
2
38
68
pampa texas
Quit your whinning cold shop. Mine is 20 degrees and I did all the posts for the carb pictures. Well I did cheat a little fired up the heater. I've got a stock head I could take a shot of a plug in it and if I can find a plug too long I could take a shot of how it would look. The power wire brushing thing I learned the hard ways some time a new plug will have a little burr where the ground electrode is welded on the plug and it acts like a lathe bit when you screw it in cuts nasty new threads so I try to make sure that the threads are clean and no burrs and the never seize will stop aluminum and steel from gaulling in most cases and it helps seal the plug. A LITTLE goes a long ways beleive me I look at neverseize and seems pretty soon I'm wearing the shlt all over me.
 

Norman

LORD VADER Moderator
Jan 16, 2008
2,605
2
38
68
pampa texas
Head what it looks like.




Head with too long of threads on plug and wrong plug just to show.



head with stock china plug and a couple of the threads showing on the head



If you pull off the head I like to resurface the head on a pane of glass with 320 wet/dry sand paper glued to the glass and wet sand it to true it up. I use water on the sand paper with a dash of soap in the water to help keep the paper from clogging up with the sanding dust. All I do is get the contacting surface a dull uniform color all the way around so this goes pretty quick. I have not done this head the area in question is what looks like a narrow ring on the head.
 

Pablo

Master Bike Builder & Forum Sponsor
Dec 28, 2007
3,665
6
38
Duvall, WA PNW
www.sickbikeparts.com
My first NGK B6HS and the stock plug are so soaked and fouled from the super rich conditions that they gave up the ghost. It probably didn't help that the aluminum anti-seize was washed down and around as well.

I'm convinced a B6HS is not the best plug for cold, wet conditions and first start/tuning conditions. I may return to it in the summer though.

SO I just received my two B5HS plugs that I bought on eBay. (great seller) I was not having luck finding B4HS or B5HS locally. And it seems B4HS is just a complete rarity. So now it's wait for decent weather and free time!!(^)