I have been reading on the web that reading the plug as we do is nonsense, since the tip and the middle of the electrode only show idle and half throttle, while the real reading, to check if you're lean etc. must be done at the very end of the center electrode i.e. where it is attached to the plug itself. To do so you need a sort of special tool, with lens and light. So I googled it and in fact there are tons of 'spark plug reading tools' for sale.
Without the tool, but with light and a lens, I tried to check my plug as far inside as I could see, and needless to say it is in fact quite more lighter than the tip, i.e. the area which I usually quickly read, and that many post here on RR when they want opinions about their plugs.
Does this 'deep-reading' technique apply only to the racing guys or to our engines as well..?
05-08-2008 12:11 AM
pgkevet Heliman Location: surrey UK
..my aged and dim memory of engines (circa 1970) recalls a glass plug insulator so you could look at the colour of the flame???
from reading through some of the sites on this second link , they seem to be saying two cycle and four cycle engines will have different ideal colors , and that synthetic oil will effect color also
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05-08-2008 12:39 AM
FCM Elite Veteran Location: Malaysia
It probably is technically correct to look 'inside' the plug but who cares? Reading the plug tip works well i.e. light coloured tip = lean mixture, dark tip = rich mixture, nice medium tan (or grey depending on oil) colour = pretty much optimum mixture. Reading 'inside' doesn't change this although it may be true that guys running full blown racing engines do need to be more precise than we do with our midly tuned, fixed speed/timing industrial 2 stroke engines.
The glass viewing plug used to be sold as 'Colourtune' if I remember. Difficult for us to use this when hovering
..heard of a Carbsmart? Well now introducing ChromaSmart the Ultimate in Gasser self-tuning modules..to be used with ChromaGov (patented frequency refractive tachometer technology) and, of course, ChromaFlex for automated collective management.
All these and more can be bought from the ChromaCon website.
"ChromaCon users have bigger Penises"
<I'll shut up now>
pgk
05-08-2008 09:04 AM
FCM Elite Veteran Location: Malaysia
I dunno, it all sounds like a load of Chromabullsh!t to me
I don't know, apparently racing guys read the tip too, but only for idle, and read the center for half throttle and the bottom for full throttle. There must be some truth because reading kits like this one are common on the web. This page explains it well.
05-08-2008 11:44 AM
copperclad Elite Veteran Location: ..
hi the sites under two cycle plug reading seem to be in line with what we have been doing , dana
I don't know, apparently racing guys read the tip too, but only for idle, and read the center for half throttle and the bottom for full throttle. There must be some truth because reading kits like this one are common on the web.
I’m enjoying this thread. I notice my buddy is not spewing foul words at you for starting it and providing actual scientific explanations as to why reading a plug is hocus pocus for a heli. In an airplane it is quite common to run full throttle for extended periods of time so reading the plug for a full power run is plausible. With a heli you are hardly ever at full throttle for very long. Unless you use head loaders …
It's not hocas pocas. I think people get confused reading plugs when they are breaking in their new engine and also running huge quantities of synthetic oil, something I do see happen here. The plug tip colour is a very good indication of how your engine is running. If is doesn't make sense when comparing this with your needles settings, then something is wrong.
Yes, you can use head loaders if you want but these are also an approximation only of the load the engine feels when flying. The really important mixture setting for helicopters is at or around the hover point. This is where the engine is operating most of it's time and this is what you see if you look at the plug after a flight whether you are hovering on the low or high needle. I know, it can be argued that you spoil the plug reading by landing and idling the engine before shut down but unless your low needle is seriously out of wack, it will not be running long enough at idle to affect the colour of the plug unless you deliberately idle for extended periods.
This is where the engine is operating most of it's time and this is what you see if you look at the plug after a flight whether you are hovering on the low or high needle.
You just shot yourself in the foot with this argument. If you are hovering on the low needle then what would the plug look like if you were to run on just the high needle? If you are hovering on the high needle then what would the plug look like if you were to run on just the low? If you are hovering on a combination of the low and high needle (which is more than likely for most of us) then what would the plug look like if you were to run on just the low or just the high? You have no idea which screw to turn and how much. Secondly, you have no control over the timing of these fixed timed engines that we use and that is part of the plug reading.
The variation in load due to regular flight far exceeds the load variation between the blades and the head loaders because you tune the head loaders to equal the load of the blades at hover (at least I did).
People are using all different plugs, different oils, different fuel/oil mixture ratios, different fuels, different run speeds, different mufflers etc., yet you think you have this plug reading down to a science. That’s a laugh. Nothing could be further from science then this hocus pocus plug reading.
shuttlepilot Elite Veteran Location: Mullins, South Carolina
Ace, with all due respect.....in laymans terms. If your plug looks black or smutty....chances are you are running too rich. If it is white-ish you are running lean. I really don't believe you can argue that. I don't think there is really a method that is a "science", but certainly not "hocus pocus" either.
Gas is Great Quick OD 26
05-09-2008 05:40 PM
Dr. Fibinotchi Key Veteran Location: Sioux Falls SD
hmm"People are using all different plugs, different oils, different fuel/oil mixture ratios, different fuels, different run speeds, different mufflers etc., yet you think you have this plug reading down to a science. That’s a laugh. Nothing could be further from science then this hocus pocus plug reading""
I agree with this completlly. Two diffrent oils Klotz and yamalube burn diffrent on my engine. I ran to temp of the engine in diffrent places and sound. If you looked at the plug you would think its way off but the engine runs perfect.
-Cody
All that a man achieves and all that he fails to achieve is the direct result of his own thoughts
05-09-2008 05:50 PM
AceBird Elite Veteran Location: Utica, NY USA
Quote
If your plug looks black or smutty....chances are you are running too rich. If it is white-ish you are running lean.
I am not denying that you can get some useful information from the plug especially when things are way off but there are people directing those that have no experience with a gas engine as though it is as reliable as a stethoscope that a doctor uses for heart beat.
It is a reliable way of dtermining if your engine is running with the correct fuel air ratio. If you want to chase engine temps/different oils/ratios/fuel to try and get everything the same then this is not the way to do it. Each fuel/oil set up should be treated seperately. The plug will not lie to you. My plug will look different to your plug for sure. But that doesn't mean you can dismiss this method of engine tuning as a black art - it isn't and thousands of gasser heli flyers know this - are they all wrong I wonder
But that doesn't mean you can dismiss this method of engine tuning as a black art - it isn't and thousands of gasser heli flyers know this - are they all wrong I wonder
Thousands of experienced gasser heli flyers who have determined over many years what "their" plug should look like, granted. But someone with no experience looking at compressed photos on an internet forum could be fooled by what they see.
