Spark plugs (2016)

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Thanks .... if I can't get the proper ones ... I'll give these a go then ... so far just tried them in the shed after primary and drive chain adjust , seemed fine then , but no load ...
Craig
 
If the engine is fouling plugs, TROUBLESHOOT the reason WHY... going up/down a heat range is madness. Fuel mixture too rich? Ignition system weak? Intermittent misfire? Oil control problem? Low compression? Choke failing to on?

More info/symptoms...

TEST.. don't guess
 
concours said:
going up/down a heat range is madness.
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I've heard that about riding/racing 40+ year-old motorcycles, $2500 electric-start kits, 70+ bhp modifications, $4000 multi=speed gearboxes etc. etc.

I mean, c'mon, lots of pics and documentation of ruined pistons and valves, broken cranks, exploded crankcases, on and on, have any of these ever been caused by the wrong range of plug? So-called madness is a common commodity among old bike enthusiasts.
 
Danno said:
concours said:
going up/down a heat range is madness.
Click to expand...


I've heard that about riding/racing 40+ year-old motorcycles, $2500 electric-start kits, 70+ bhp modifications, $4000 multi=speed gearboxes etc. etc.

I mean, c'mon, lots of pics and documentation of ruined pistons and valves, broken cranks, exploded crankcases, on and on, have any of these ever been caused by the wrong range of plug? So-called madness is a common commodity among old bike enthusiasts.
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What I mean is: a heat range up/down on a (I can assume) street driven bike not being held at WOT for significant periods of time is jousting at windmills, there is a significant problem that must be addressed by troubleshooting. Then, the subtle tuning can be worked. There is a gross error as it stands, which must be remedied. JMWO :mrgreen:

OP, compression tested recently? Basics here... Suck/squeeze/bang/blow. Some tests to rule things out.
 
Craig said:
Thanks .... if I can't get the proper ones ... I'll give these a go then ... so far just tried them in the shed after primary and drive chain adjust , seemed fine then , but no load ...
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I wouldn't worry about it.

If you are going to use resistor plugs then you don't need resistor plug caps as well, use one or the other.
 
Yup , just the plugs will be resistor and I'm not sure I really need them with the Boyer MK4 .... I can't use multitester anywhere near the bike when it's running and thought maybe resistor plugs might help .... not much of a electrician or mechanic .... I am curious about how well my charging system is working .... the battery is 5 years old .... I am having no problems with it just curious...
Craig
 
Craig said:
Yup , just the plugs will be resistor and I'm not sure I really need them with the Boyer MK4 ....
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Correct, the Boyer MkIII and IV don't actually need resistors (unlike most digital ignition systems).
 
hello ... I got a pair of BPR7ES at crappy tire ( Canadian Tire ) this morning .... I did not see any BP7ES ... the package reads 3BPR7ES .... I went to counter and the young lady typed in the product code , it spit back BPR7ES , also BPR7ES cast into the plug themselves .... can't find any mention why a 3 would be used as a preface .... thoughts anyone .... I hope it doesn't mean they are knockoffs .... the local bike shop say sometimes that happens at Crappy Tire...
Craig
 
concours said:
What I mean is: a heat range up/down on a (I can assume) street driven bike not being held at WOT for significant periods of time is jousting at windmills, there is a significant problem that must be addressed by troubleshooting. Then, the subtle tuning can be worked. There is a gross error as it stands, which must be remedied. JMWO :mrgreen:


.
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Not just in this forum but in a lot of other ones too, there seems to be those that think an oily fouled plug or fluffy black fouled plug is a problem that can be cured with a hotter plug. A hotter plug won't suddenly come out looking a beautiful light tan if used in an oiling cylinder or if the mix is wrong.
 
Biscuit said:
concours said:
What I mean is: a heat range up/down on a (I can assume) street driven bike not being held at WOT for significant periods of time is jousting at windmills, there is a significant problem that must be addressed by troubleshooting. Then, the subtle tuning can be worked. There is a gross error as it stands, which must be remedied. JMWO :mrgreen:


.
Click to expand...

Not just in this forum but in a lot of other ones too, there seems to be those that think an oily fouled plug or fluffy black fouled plug is a problem that can be cured with a hotter plug. A hotter plug won't suddenly come out looking a beautiful light tan if used in an oiling cylinder or if the mix is wrong.
Click to expand...

Also on all forums; those who speak of those who disagree by harumphing, puffing the pipes, slipping on the slippers and acting as if any divergent opinion is ridiculous. I don't disagree about the troubleshooting, mixture adjustment, compression testing, etc. but can any of the esteemed posters tell me why the BP6ES is just fine for an air-cooled Triumph twin, but death for a Norton? Or is it just a matter of belief based on hearsay and not actual experience? Lets hear from the experienced who actually KNOW something. The rest of us are just believers.
 
I used BP6ES in my bike a few years ago because I was getting a misfire on right side ..... turned out it was a broken wire on Boyer pickup .... the hotter plug didn't seem to hurt the left side though ... I thought the 6 was the next hot step up from 7 so didn't worry about doing damage .... I have been told one range up or down on plugs is no biggie .... like I say I'm no mechanic , that reasoning seemed sensible to me ...
Craig
 
Danno said:
Biscuit said:
concours said:
What I mean is: a heat range up/down on a (I can assume) street driven bike not being held at WOT for significant periods of time is jousting at windmills, there is a significant problem that must be addressed by troubleshooting. Then, the subtle tuning can be worked. There is a gross error as it stands, which must be remedied. JMWO :mrgreen:


.
Click to expand...

Not just in this forum but in a lot of other ones too, there seems to be those that think an oily fouled plug or fluffy black fouled plug is a problem that can be cured with a hotter plug. A hotter plug won't suddenly come out looking a beautiful light tan if used in an oiling cylinder or if the mix is wrong.
Click to expand...

Also on all forums; those who speak of those who disagree by harumphing, puffing the pipes, slipping on the slippers and acting as if any divergent opinion is ridiculous. I don't disagree about the troubleshooting, mixture adjustment, compression testing, etc. but can any of the esteemed posters tell me why the BP6ES is just fine for an air-cooled Triumph twin, but death for a Norton? Or is it just a matter of belief based on hearsay and not actual experience? Lets hear from the experienced who actually KNOW something. The rest of us are just believers.
Click to expand...


OK, the slippers are coming off!

A Champion N3C is one plug range cooler than that recommended by the OEM. The OP stated a plug fouling issue. Diagnostics 101 suggest coming from a known and changing to plugs back to an OEM recommended warmer heat range seems pretty reasonable to me and I think pete.v summarized it very nicely early on in this thread. Plugs can and do foul for a variety of reasons so remove one of the reasons by going up a heat range with a protruding electrode per manufacturers recommendation. As lead beater suggested, maybe the plugs are of bogus quality.


esteemed posters tell me why the BP6ES is just fine for an air-cooled Triumph twin, but death for a Norton
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First, in my mind, there are no esteemed posters here, just Norton enthusiasts. Many people bring many things to this forum and tribalism adds nothing here. As for the question as to "why the BP6ES is just fine for an air-cooled Triumph twin"'; that is best left to the OEM's. Best as I can tell, nobody mentioned "death for a Norton". I suppose plug recommendations are based on a range of expected conditions. Maybe Triumph simply did plug chops and the plug readings indicated this is the heat range the motor wants - how novel!

For reference, with most of my race engines I run BP9EV (two steps cooler than OEM recommendations) as heat can be a problem with aggressive race engines and keeping the plug clean is not a problem.
 
The NGK site say the BP6ES would be 1 range hotter than the BP7ES .... counter intuitive but that what NGK info. site claims
Craig
 
Craig said:
The NGK site say the BP6ES would be 1 range hotter than the BP7ES .... counter intuitive but that what NGK info. site claims
Craig
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Yes, and as best as I can tell the Champion cross reference seems to indicate a N3C is one step cooler than a BP7ES.
 
Iridium plugs technology has proved durable, 50000 miles in the missus BMW 318i on one set and still going strong. The iridium allows an optimum pointy electrode design to have long life. I use NGK wherever I can, but when I looked for the Commando I couldnt find an obvious cross reference.

So I fitted Denso IW22 and am very happy with them, I would suggest that if fitting them did not cure the OPs problem, then the problem is not the plugs.
 
Got 20000 Km on the 4 NGK iridiums in the Ducati ..... will check on them next spring when I look at valve train ....
so far so good
Craig
 
I think that spark plugs are spark plugs, and brand really makes no difference, this of course, is assuming the correct cross-referenced heat range and type is used and you don't get a hold of a defective plug in the first place (rare). Not only combustion chamber shape but head material and design come into play when manufacturers spec a certain plug. I think cooler plugs are spec'd for engines that can't get rid of head heat easily. My 850 is spec'd for Champion N 7's. This is hotter than the N 3's spec'd for the op's 750. Does the lower compression ratio of the 850 translate to a cooler running head? And is that why the plug needs to be hotter? My guess is yes. As far as what works in Triumph twins or Ducati's for that matter, different animals. And of course racing too puts extraordinary demands on an engine with a lot more heat to get rid of so it's no wonder cooler plugs are needed. On a road bike, I really don't think it does make a lot of difference if the heat range is 1 hotter or 1 cooler but my point is don't expect to tune out plug fouling for any reason with a heat range change without making sure the rest of the engine condition and tune is up to snuff.
 
Danno said:
Also on all forums; those who speak of those who disagree by harumphing, puffing the pipes, slipping on the slippers and acting as if any divergent opinion is ridiculous. I don't disagree about the troubleshooting, mixture adjustment, compression testing, etc. but can any of the esteemed posters tell me why the BP6ES is just fine for an air-cooled Triumph twin, but death for a Norton? Or is it just a matter of belief based on hearsay and not actual experience? Lets hear from the experienced who actually KNOW something. The rest of us are just believers.
Click to expand...

I do not think the bp6es is death for Norton. No 2 bikes are exactly alike and a few just may run better with that plug. There is nothing written in stone except for some peoples iron clad opinions.

However, with the Triumphs timing being around 36 BTDC, the BP6ES would be Normal for them.
 
All you guys are esteemed to me for your experience and enthusiasm. I just like to know the real reason when I hear something that doesn't make sense to me. Jim C. said get those 6s out of there "before it's too late." Maybe he has had or knows someone who has had a less than positive experience with one range hotter than recommended plugs in a street motor with nearly zero performance mods.

Today I received the 8-pack of NOS Champion N4G plugs and immediately replaced the BP6ES plugs with a pair of these antiques. Still seems to be a little fat. I noticed he mains are 240s, but haven't really had it on full throttle yet. The Burlens Amal tuning guide says nothing wrong with starting 2 ranges high on the mains and the factory book says 220s. I guess next step will be dropping the needles to the top notch from the middle.
 
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