Honda-SOHC
SOHC.co.uk Forums => CB750 => Topic started by: Martin6 on March 13, 2023, 07:01:21 PM
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I spent a very pleasant afternoon in the garage today, chasing down my warm tickover issue (off the choke).
A basic question: One thing I noticed, the manual specifies NGK D8ES plugs. David Silver sells DR8ES and this is what I have on the bike. Does the 'R' mean resistor? I also have 5k-Ohm plug caps. Is it OK to run resistor plugs together with resistor caps?
Thanks, Martin
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No, you either use resisted plugs OR resisted caps. The usual combination used is D8EA's with NGK resisted plugs.
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What I know, that R really means resistor, but not 100% sure. And running resistor plugs with resistor caps is definitely not OK.
You can confirm if plugs have resistor by measuring them with multimeter
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I feel they work fine together, there's debate to be had but one forum member won't let that happen ::)
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Mine works fine with resistors in both….at least for now. I’m also confident that if those on this forum have experienced issues, they certainty exist.
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Martin has the correct plugs in his bike, as he said the manual states D8ES. The ones David Silver sells are DR8ES. The modern alternative to the D8ES, which NGK stopped making years ago, are the D8EA.
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Absolutely, I had a right going on with Greenspark after being wrong footed by DS. Do they know? Oh, Greenspark we’re excellent by the way.
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Absolutely, I had ar right going on with Greenspark after being wrong footed by DS. Do they know?
DS has been told by hundreds of people on hundreds of occasions 🙄🙄🙄
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Dear me….I’ll add to the numbers 😁😳
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Gave up with NGK plugs some years ago now, with too many copies floating about and only use Denso now, and much better spark ;)
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Martin has the correct plugs in his bike, as he said the manual states D8ES. The ones David Silver sells are DR8ES. The modern alternative to the D8ES, which NGK stopped making years ago, are the D8EA.
Unfortunately, i don't have the correct plugs. I have the DR, resistor plugs, as well as the resistor caps. Could this be the cause of my poor running? It starts OK, but needs throttle and dies once the choke is off. Timing and points gap checks out OK. Valve clearances are fine. An afternoon on the carbs tomorrow, but I'll be looking for D8ES plugs from a reputable source.
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Or take Triggers tip and go alternative….?
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Which Denso plugs? X-24ES?
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Which Denso plugs? X-24ES?
24's are fine on a 750 sohc ;)
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Thanks :)
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Which Denso plugs? X-24ES?
24's are fine on a 750 sohc ;)
What is DENSO alternative for 500/550?
DENSO is not copied as NGK?
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Which Denso plugs? X-24ES?
24's are fine on a 750 sohc ;)
What is DENSO alternative for 500/550?
DENSO is not copied as NGK?
X-24ES for 400 four, X-22ES for 500 four, 550's and X-24 for 750K's ;)
Never come across a copy Denso to date .
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Which Denso plugs? X-24ES?
I bought a box of 10 Denso plugs from here Martin, reasonably priced as well, in fact cheap.
https://www.gsparkplug.com/1x-denso-standard-spark-plugs-x24es-u-x24esu-067800-1700-0678004130-4099.html
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£25 for 10No inc post👍
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Which Denso plugs? X-24ES?
24's are fine on a 750 sohc ;)
What is DENSO alternative for 500/550?
DENSO is not copied as NGK?
My workshop manual and owners manual quotes X22ES for 500s. Denso no 4090.
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Quite right it should be X22ES, that would have been what I bought, they've been in a box in the loft ever since.
TBH I've never used Denso except for a time in the 70s, I've always used NGK but for the price of the Denso plugs now I'll take a chance on them, plus no copies unlike the NGK plugs
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I've been using Denso X-24ES-U plugs in my 750F1 since I got the bike on the road after rebuild around 2008i sh and they work a lot better than the NGK's now that you can't get the proper ones (D8ES-L).
Cheers
Dennis
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Which Denso plugs? X-24ES?
24's are fine on a 750 sohc ;)
What is DENSO alternative for 500/550?
DENSO is not copied as NGK?
My workshop manual and owners manual quotes X22ES for 500s. Denso no 4090.
That is correct :o but, you can use either . The X-24 are a hotter running plug than the X-22 and i have found if you are only using the bike in fine spring and summer weather the X-24 are a better plug, which have been superseded to the X-24 ES-U . Seeing most members that do ride a SOHC, don't ride in cold conditions ;)
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Forgot to mention before. It is not just spark plugs that have superseded over the years, it is also fuel. The X-24ES-U is more suitable for E5 and E10 petrol ;)
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Please, do tell…..
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I was under the impression that colder plugs had higher number than hotter plugs. So an X24ES plug would be colder not hotter. As it happens it's recommended by NGK to go a step colder when using Ethanol so the X24ES would be better if that's the case.
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I was talking about DENSO plugs, NOT NGK :o I think you need to go back to spark plug school as, they are a lot more complicated these days ;)
All spark plug manufactures have there own heat range, and that is heat transfer from the engine. The plug can differ from standard copper up to Iridium which all have there own heat dispersal ;)
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The key point here is that higher performance engines require a ‘colder’ plug to help disperse the resultant heat from combustion faster. The ceramic insulators on ‘colder’ plugs are generally smaller, allowing faster heat dispersion.
In the Denso terminology, the bigger the number the colder the plug. So an X-22 is a ‘hotter’ plug compared with the X-24 which is ‘colder’ in Denso terminology.
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And as far as I can determine that’s exactly what I said, higher number colder. So an X24es would be a colder plug than the X22es not hotter.
Maybe I was there that day.
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The key point here is that higher performance engines require a ‘colder’ plug to help disperse the resultant heat from combustion faster. The ceramic insulators on ‘colder’ plugs are generally smaller, allowing faster heat dispersion.
In the Denso terminology, the bigger the number the colder the plug. So an X-22 is a ‘hotter’ plug compared with the X-24 which is ‘colder’ in Denso terminology.
I agree James but with the nature of interpretation I describe the colder plug as having larger insulation for more dispersion in surface area from plug tip to plug wall and then onward to the cylinder head casting.
[attachimg=1]
It is a bit semantics though as so many describe in opposite direction as I've found over the years, champions I always have to reference the numbers as it just doesn't stick in my mind like NGK :)
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The key point here is that higher performance engines require a ‘colder’ plug to help disperse the resultant heat from combustion faster. The ceramic insulators on ‘colder’ plugs are generally smaller, allowing faster heat dispersion.
In the Denso terminology, the bigger the number the colder the plug. So an X-22 is a ‘hotter’ plug compared with the X-24 which is ‘colder’ in Denso terminology.
I agree James but with the nature of interpretation I describe the colder plug as having larger insulation for more dispersion in surface area from plug tip to plug wall and then onward to the cylinder head casting.
(Attachment Link)
It is a bit semantics though as so many describe in opposite direction as I've found over the years, champions I always have to reference the numbers as it just doesn't stick in my mind like NGK :)
Fair point (late night post). What I probably should have referenced was the ‘gas pocket’ clearly shown in your pics above. In Denso speak ‘colder’ plugs generally have a larger gas pocket, and larger ceramic insulator / surface area, hence slower heat dispersion away from the plug (and vice versa).
Sent from my iPhone using Tapatalk Pro
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I was under the impression that colder plugs had higher number than hotter plugs. So an X24ES plug would be colder not hotter. As it happens it's recommended by NGK to go a step colder when using Ethanol so the X24ES would be better if that's the case.
I have been using D8 in my 500,and 200,
the 500 runs well,
ordered 6 X24 to try,
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I was under the impression that colder plugs had higher number than hotter plugs. So an X24ES plug would be colder not hotter. As it happens it's recommended by NGK to go a step colder when using Ethanol so the X24ES would be better if that's the case.
I have been using D8 in my 500,and 200,
the 500 runs well,
ordered 6 X24 to try,
Okay sitting outside in the welcome sunshine, listening to Simon Mayo album show, before going over to Johnny Walker,
Fitting the new Denso x24 plug
2 for the 200,at 25thou
4 for the 500,set at 32thou,
Started up,both running sweetly
These are the D8 ngk out of the 500,
A little dark on the outside, during to starting to warm it up,I find the plug come out easily if it's warm
(https://uploads.tapatalk-cdn.com/20230319/1f48081c261e547f55666a8046e1ebd2.jpg)
Sent from my SM-A750FN using Tapatalk
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32 thou John, that's a little wide, pretty sure they should be 25 thou or something like.
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32 thou John, that's a little wide, pretty sure they should be 25 thou or something like.
With the Boyer giving a nice fat spark I make use of it
Gives what appears to be a good burn, look how clean the plugs are,
The engine seems to like it,
Very responsive
Sent from my SM-A750FN using Tapatalk