new carbs questions

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here are the plugs i have in garage champion N4G (the ones in bike now) champion N7YC NGK BP7ES NGK BP6ES which one??
 
A plug with the right reach, thread pitch, and heat range made by any manufacturer will work in a Norton head. I've used at least 5 different manufacturer's plugs testing this theory, and that's nothing compared to how many plugs would work. What is giving me great results is an Autolite APP 5224. Even though it is spec'd with the same reach as a BP7ES, it has 2mm more reach at the ground electrode, uses a 5/8" wrench, is a resistor plug, and is hotter than an NGK 7 series plug. I'm not always nice to my motor, and shift into 4th around 70 every time the opportunity arises. If it was a pristine restoration, I might not do that. If my motor was going to blow up, it would have already done so many times. I can't figure out why it hasn't. It probably wants me to get really far from home first, then blow up. Anyway, I can't use BP7ES plugs with my ignition setup. Well, I can, they just don't work that well. Enough about what works for my madness.

If you are using resistor caps with EI try the BP6ES. I seriously doubt you would burn up your motor if your plugs are currently black from fuel and you ride the way you have stated. If you need to hear that from somebody else, it might be a while. It could be considered coloring outside the lines.
 
Or blasphemy to some... I've come to really like the NGK BPR7 EIX or whatever those pointy bastards are.... All of the crud flying about inside my scruffy old cylinders seems to fall off without sticking onto them as it does the regular plugs.
 
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BPR6es are definitley too hot. I run 8's in mine and they have good color and I don't ride much more than 55-60mph. You are too rich somewhere. Likely the pilot jet. Do you have the carbs with the fixed pilot or the removable pilot.
 
Schwany said:
Race gas should start a Norton by just staring at the Norton in anger.

When did Austin sell a Mini with 1 SU on it? Or is that an aftermarket solution for lazy tuners?
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Seems the Coopers got twin carbies, most other models were singles.
 
jbruney said:
Or blasphemy to some... I've come to really like the NGK BPR7 EIX or whatever those pointy bastards are.... All of the crud flying about inside my scruffy old cylinders seems to fall off without sticking onto them as it does the regular plugs.
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Currently running the same (as per my pic) without issues...
Have just bought some cheap NOS 'Unipart' plugs (does that name mean anything outside of the UK?) advertised as: BPR7ES 'equivalents', will be interesting to see how they fare.....
 
Yours look nearly identical to mine EstuaryBoy.... and never a misfire, whereas by this time I'd have burned through 3 pairs of BP7 ES. I'll choose reliability over chasing perfection every time for some reason I've been unable to fathom because I'm picky about what is crammed on my pile of nuts & bolts..... Not so much of how it looks.

SU carbs are truly beasts.... Had one which made an old '50 model panhead howl at the moon as a man child... 100% reliable, puked fuel all over my leg, improved performance vastly, looked so good, but it was quite large..... I wander again as the wife says....
 
gortnipper said:
Yes. Or a N7YC. Same same for this case.
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Agree... as suggested elsewhere, anything that replicates the OE plug, assuming the engine has no radical reworking or is not being used in abnormal conditions...
My NGK endorsement was simply through familiarity of use, until digital ignition prompted a change to plugs with an: 'R' in the title :)
 
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Tornado said:
Seems the Coopers got twin carbies, most other models were singles.
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My 989 Austin Mini had dual carburetors on it, which is what got me to wondering about which Austin Mini models only had a single SU. I don't recall ever seeing a single carburetor model. Go carts with a license plate and a roof. Friend had a pair of stacks from an 48 IDA Weber sticking out of his hood on a Cooper. That thing was a lot of fun to drive. It left Corvettes crying for mama on a road course.
 
i gonna try some NGK BPR7EIX and i also sent a message to Amal asking for their thoughts
will keep you'uns posted
 
Apologies if this is a: Granny/Eggs scenario, but the BPR7EIX are resistor plugs, so worth checking their compatibility with your ignition and plug caps, perhaps?
 
My bad. I was under the impression that this Champion N4G plug was the same heat range as a 7 series NGK plug. I looked, and it looks like it is closer to a NGK 9, which is too cold. I suggested the 6 because it is only one step warmer than a 7. No big deal, because a 7 is not that hot. However, a 6 is considerably warmer than the Champion 4.

That NGK BPR7EIX should be correct and give you the waffle gold you desire. One would hope anyway. Unless you can't use a resistor plug as mentioned.

alan hodge said:
champion N4G
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Triton Thrasher said:
Almost all Austin Minis had a single SU.
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OK. I guess I was hanging with the wrong crowd. Those crazy performance oriented types. The imports that I saw here in the USA were all dual carbureted, even the 850's. That said, I didn't see that many, and never a new one in a dealer show room.
 
have pazon surefire and solid copper core wires and non resistor caps so BPR7EIX wont work?
 
Schwany said:
OK. I guess I was hanging with the wrong crowd. Those crazy performance oriented types. The imports that I saw here in the USA were all dual carbureted, even the 850's. That said, I didn't see that many, and never a new one in a dealer show room.
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I must admit I didn’t know there were twin carb 850s.
 
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