I've seen a chart on plug color and how it relates to mixture, but I just can't find it! I thought someone here knows a link or can take a look at the attached picture. Lean or OK?

Thanks,
Shaun Bell

Just about ideal , Shaun.

Maybe just a touch richer on top end (1/16th turn on walbro). Idle looks real good.

That's only because I like to see just a touch more brownish tinge, incase things get a little on the hot side.

Otherwise, I'd be happy with that.

Good job!

Scott

Whitish=lean
Black=rich
TAN=GOOD SETTING

Your plug looks like it has been run a tad lean to me

My engine seems a bit rich from the factory and burbles,
if it is black, will this permanently foul the plug or
will the plug clean itself when I lean the needles ?

Pretty much. Just don't go too lean to try and help clean it up.
Personally I like to see a brown like a maple syrup color on the porcelain.
The metal sleeve will tell you idle, so you can get both set right.

If you notice in the picture there are little brown spots on the porcelain, and a powdery looking coat. That means it is burning the oil, and it is on the cusp of being lean on top. Although without knowing the brand of oil that is kind of speculative (no pun intended).

The metal sleeve is dry and light black, that is a good low end setting. If this engine is in a cowl it may just need a little more air flow over the cylinder, otherwise I'd just touch the top end.

Scott

a little lean in high end

Just a thought...I've noticed that the plug on some inverted cylinder engines tends to look darker and oily, even when running correct. Something about being upside down, or it could be oil is collecting on the plug while the engine is not running??

Kevin

Way too lean.....

I work on 2- strokes for a living....

for verification......Go to www.rivay-yamaha.com
I pretty much run the atv performance forum on there.....i run alcohol,nitromethane and nitrous oxide......

but all 2 stroke jetting is the same.....

You want the porcelain to be light to dark brown.....never grey......grey is too much heat......The outer ring where the thread start is your top end.....wide open throttle.....
it needs to be black to maybe a little damp when you pull the plug out.....also, always check the plug after you shut it off at full throttle.....other words....tie yur plane down and run at full throttle sor a few seconds. shut it down with the ignition. do not let it idle...look at your plug.....should be black to damp on the outer ring.......top end is now set for the moment.....now restart and put it at about half throttle.....it should blubber a little....it should not be smooth.....if its smooth, then richen up the low end screw until it blubbers a little.....now go to your desired idle setting.......
let idle for a minute...now transition it to full throttle.....do this quickly....if it stumbles a little like its rich thats ok....but if it hesitates then goes it is still lean.....richen slightly.....remember to do adjustments in 1/8 turn increments......
now...this is the hardest your engine will ever pull because its tied down.....now when you put it in the air it will lean out slightly due to not hardly any load......this adjustment on the ground is just a great starting point or final adjustment.....
while flying in normal flight path (straight and upright).....at half throttle or a little less listen to your engine....it should be blubbering slightly.....if its smooth then you need to land and richen it up slightly......if its already blubbery and sounds good then transition it to full throttle....if it cleans and goes immediately then its good.....if it blubbers for a second or tow then its rich...but that is ok....if you dont mind it doing that.....but if your hovering or doing stuff close to the ground then i recommend leaning it slightly.......now your midrange is set.....fly it full throttle in a slight down angle.....not a dive......if its smooth then you need to land and richen until it blubbers a little....once you get it to blubeer then go ahead and lean it slightly to where its smooth one second then blubbery another....this is a good top end setting so you dont build to much heat..........

Also you heat can be determined by looking at how far back the arm the color is changing.....the arm that you adjust you gap is what im talking about......if you notice in your picture it starts getting brown or black way back and down by the threads../?????
it should be this color on the top .....about half way between the end of the arm and where it just starts to bend and go down to the threads........

these recommendations are for people who dont understand tuning 100% and dont want to burn their expensive engine up.....not all will agree....but ill gurantee you that if you follow my recommendation you will only burn up or foul out a $3.00 plug and not a 1,000.00 engine..........

leaner situations are acceptable if you understand when you can and cant fly at full throttle at extensive amount of times.......


i will post a jetting procedure with pics.....

this will help get rid of any confusion......email me with any questions.......


Tim

I agree. . it's wayy to lean on the top end, probably close to 1/8 turn, but the bottom end seems to be about right.
I'd open the top 1/8 turn, fly it one flight, and see what the color is.

As for setting needles for a "blubbery" midrange, I think not. I set mine for a clean midrange and transition, with perhaps just a tad of richness on the bottom end for ease of starting and good cold (long "coasts" during landings need to be a tad richer in case of a go-around) throttle response. . .IF I can get them this way, then make sure teh top end is not too lean by looking at the sparkplugs.

I like to see a mid-tan colored center and side electrode, with a darker colored insulator and dk-brown/black body of the plug. White/powdery looking electrodes translate into too lean, a "glazed" looking insulator and wide "annealing ring" on the center electrode say too much heat. Black "specks" on a white electode say WAY too much heat and lean mixture, since pre-ignition or detonation are knocking carbon flakes off the piston, and they are coating the electrode. . BAD idea.

Go 1/8 richer on the high end needle, and forget about this "Max-RPM" frenzy. You do 90% of your flying in the mid-range. . . make the engine run best in that part of the rpm band, and the top end will take care of itself.

You're a little lean. A brownish tan color is best. If you are running a Walbro try a 16th to an 1/8th of a turn out on the top and check the plug after a few flights and see what happens.