Kiss my Keyster (carb kit needles)

[clarenceada]

Hi, Steve:
Can we just drop the usual veil of the internet for a moment and let me talk on a personal level without any rancor intended on my part (slap me if I get maudlin) and not have to back everything right now with outside verification, although I can if you want.

If you will look at the time of the my post: 8:55am I had been up for 36 hours due to my wife having health problems and my continuing dealing with the after affects of a certain "little Asian war". It mostly effects my ability to get a good night sleep, sleep deprivation, the doctors call it (I do get some interesting dreams). It makes me giddy and I was just pulling your chain' after you posted the "plug chart". this forum and working on bikes is like therapy for me and helped. I got some sleep, so here goes.

This chart has been around since the '60, you would see it in every mechanics shop, and it was made for high mileage car engines to show the effects of mechanical problems with the engines. That's why I asked if there was oil on the threads of the plug; if the engine isn't in good mechanical condition, any plug reading is going to be false due to oil getting on the porcelain.

Snakeoil is right, use an oxygen analyzer and a dyno. But don't stop there; have the intake hooked-up to an a flow meter, use an electronic ignition analyzer, put electrodes all over the engine to monitor head temp etc, etc.
But to use plug reading as a way of tuning an older Honda engine is difficult even in the best of shops with all the technology you want to throw at it. And every time you do a plug reading it needs to be done Exactly the same way, same rider, take account of the air temp, humidity (yes, the flame front inside of the engine travels at different speeds just by changing the humidity) ect. through more variables then I want to get into right now.

The thing is (not so much for newer stuff with programmable computers and fuel injection) tuning used to be more of an art then a science: look at Pop's Yoshimura, back in the day:

http://clingonforlife.blogspot.com/2010 ... imura.html

I've seen videos of him at the race track and he's got his hands on the bike when it first starts, to see how it's warming up, he had some kind of steth-o-scope and listened all over the engine, when the rider came by for a test run he was right close to the track listening to it as it went by.
All the other tuners at the time had the same technology but he made it work better then most because he was an artist. Engines are just an air pump and has like a musical instrument, the need to be tuned in the intake track and exhaust pipe. I worked part time when in college for an electric organ tuner and it was half electronics and half having a good ear to be able to tune it (and no I never got that good at it---solid state killed his job like TV repair)

Not saying I don't look at plugs and can tell if it's too rich
or lean but it's a broad measure. If I have done my work right and EVERYTHING is up to factory specs then there shouldn't be any problem (that's after doing everything LM has on his tuning page too).

Steve, I do want to say I do appreciate what you have done around here especially in the electric/ignition side and your tutorials. Sometimes it does seem you post to threads (mostly in the mechanical section) without reading the whole thing (possible you speed read) or off the top of your head without double checking your facts. I was taught to speed read in high school through one of them 60's federal programs, and I had to teach my self later on to Slow down when reading technical books as I wasn't picking up all that was on the page.

For Christmas I was given the book "The man who saved Britain: a personal journey into the disturbing world of James Bond" By Simon Winder. Which is a look at Britain after the ww2 and "the trauma faced by Britain in the 40's and 50's after the loss of the British Empire" and how James Bond was one of the few high lights of that time. I never quite understood how much England had lost thru the war; I thought we had won the war together and were equal partners but as Britain was losing there empire America was increasing it's influence world wide---along with China and The USSR. So maybe this is where you get your acidic sense of humor which I like (even if a little strange:-)

I know I get too far off the subject a lot of times and tend to go on but I hope you all will forgive me.


Clarence

Clarence, far be it from me to challenge any of Newton's Laws of Physics. If you're serious, or being just plain argumentative, please read, and comprehend, my posts again.

I've never had much luck reading carbs; might as well be a pot of tea for all the good, looking at a bunch of smudge marks on the end of a plug does me.

If you view the 'Common spark plug conditions' chart document (by clicking on it to open, then click again on the opened image to size it up) that I posted for you (in order to help), you'll see that none has anything other than a darkened body; and that is in spite of, and irrespective of, the colour and state of the electrodes or insulators. Not that it couldn't occur -- just that, in over forty years of playing with petrol engines, I've never seen such a phenomenon. Still, as I've always stated: 'every day's a schoolday!'. As always, I stand to be corrected.

If you're not serious, nor being just plain argumentative, please ignore the foregoing.....?

[e3steve]

Clarence, it is said that one should "wait a while before clicking SEND" when one has composed an email. We are all guilty of not doing so, I'm sure; but I try to read and re-read my scribe to understand how it might be interpreted by the recipient. The trouble with writing, to the reader, is that each of us processes thoughts entirely differently and interprets or misinterprets the actual intended meanings.

No rancour from my quarter. We're all pals and sometimes we must agree to differ. I, for one, get enough earache & arse-ache from the old woman, so I come here to lighten my moods. And I always try to inject a little (sometimes-caustic) humour into posts.

Guilty of speed reading and of sometimes not fully absorbing the info? Well, I've just tied my own shoelaces together as a penance, so that says it all! ☺

'Nuff said.

[jensen]

Hi,

Interesting post, at least for the technical issue's.
Reading plugs isn't my thing, too complicated.

One will never know how much oil the engine is using, and how much is burnt.
Closing the carb (shutting off) while riding sucks oil through the valveguides.

It's hard to predict what effect it has on the color.
Screwing the plug in and out again and again isn't good either.

I like the word dyno in your mail, Clarence, I think I stick to that.
And when my starts bike to misbehave and there's no dyno in the neighborhood, well, I have to keep this post in mind,

Jensen

[Hotshoe]

Thanks for posting those links Brew, the one by Gordon Jennings really jumps out at me.
It's kinda buried but here's the path from the http://faq.f650.com/FAQs/SparkPlugFAQ.htm#Plug link:

Procedures -- PLUG CHOPS -- FOR PLUG READS -- www.strappe.com

He was a mover and shaker in the motorcycle scene during the 305's era and was really well known for his technical writing.... I wish I'd read more of his stuff at the time rather than digging through Cycle News looking for my name in their race results.
It's a bit long winded but worth reading for those interested in learning from experience.

[teazer]

Great thread. First off, plug chops are really only good at wide open full load and that's because that's when the plug is hottest. At anything less than WOT, the plug is cooler and will have more colour regardless of the jetting.

The way I read a plug is to get a 10x magnifying glass and strong light to check the mixture ring deep down where the insulator meets the steel shell. I want to see 1-2mm wide strip of brown or greay down there. The insulator nose at WOT should be clean and more or less white but not bleached looking.

Side and center electrodes tell you how hot they got at WOT - nothing more nothing less. If the heat range is wrong or timing is off, that makes a huge difference to overall plug temperatures and the tip temps. You want to see the side and center electrodes with the color burned clean for about half their length.

If the tips are rounded or there is any cement boil the plug is getting too hot. First get the right heat range for your tests and then get the timing right and then fine tune the main jet.

So that's all great for a race bike but it's also OK for a street bike, but it's easier on a dyno with gas analysis.

Doing a plug chop at less than WOT should leave more color on the plug but as an absolute measure, it doesn't tell you much of anything. It's a good comparative tool if conditions are the same from one chop to another. Not much use trying to compare a flat out chop on a cold day with tootling around the block on a warm day and trying to make much sense out of the difference.

What plug reading tells you is the temperature that it reached more fuel and it's darker, retard the timing slightly and it will be darker because it's running cooler.

[Snakeoil]

Hotshoe,

Thanks for posting that link to Gordon Jennings article. I always read his articles back in the day and this one is a keeper for sure. Pretty much most of what has been discussed here is mentioned in that article and more. He also gives the relationships between all. That's key in my opinion. I think we all have a decent grasp of the basic concepts, but to know the details of how they interrelate is what separates the guys on the podium from the also-rans.

For vintage bikes, regardless of the brand, and the world of changing gasoline characteristics, I think this might become more important to understand than ever before. It's not only the go-fast guy trying to safely squeeze ever hp they can from their engines, but the run of the mill vintage bike owners who run OEM spec bikes on nothing near the gasoline they were intended to run on.

I've cut and pasted this article into a Word document and saved it to my hard drive for future reference. I'm sure I'll go back to it again and again.

Thanks and regards,

Rob

[teazer]

That old Jennings article should be mandatory reading. Thanks for the link. I still have a paper copy of that article somewhere filed away.