Tuning mixture by plug color

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computeruser

computeruser

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Plug color? That would require you to have and install a new plug in order to tune. If the existing one isn’t broken, why would you change it? And what would you then do with the perfectly serviceable one you removed?

I think pretty much all of my saws, mower, etc are in original plugs and still run fine >10 years later. Saw tuning is by ear and feel in the cut, sometimes verified by a tach out of curiosity.
 
buttercup

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Whats wrong with four stroke until cutting?
I just cant see it any simpler and more easily understanding than that.
You want it more complicated or what ?
 

RTK

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Whats wrong with four stroke until cutting?
I just cant see it any simpler and more easily understanding than that.
You want it more complicated or what ?

Nothing wrong with doing it that way and no one said it wasn’t. Since we don’t have EGT’s, CHT’s, fuel flow, etc. it is one more way to tell how your mixture is set, that’s all. I wanted to know if anyone here used it.
 

Evan

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I thought this sled was running lean it may actually be fat on the bottom and lean up top. It's running about 700rpm over its recomended 8500 . I'll do clutching before any jetting.
The plug color set my mind at slight ease I'm still not going to hold it wide open for long runs because my ear says shes lean and il trust it more than an all around color from a days ridding and idling
 

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Cliff R

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Difficult if not near impossible to tune anything on this new fuel reading plugs.

The only effective way to tune is to make sure the engine "four strokes" at no-load, then cleans up quickly and pulls strong in the cut. Anytime the load is removed it should instantly "four stroke". If you try to lean things up for more RPM's and don't make sure this is happening smoking the P/C becomes a real possibility.

Rev-limiting and timing-retarding coils make this sort of tuning a bit more difficult, but in any and all cases er just little more toward being rich than lean. I find that with some of these newer saws with rev-limiting coils you have to sneak up on the best tune starting out noticeably rich then leaning it up a little with each cut until you find the best setting. This happens mostly with coils that have a relatively low RPM cut-in point, others are high enough it's really not a big player with finding the best tune.

Correct tuning is a big deal when it comes to 2-stroke power equipment. We continue to read about folks "smoking" P/C's on here, especially with Echo saws. This ONLY happens because the owner/operator is NOT taking the time to remove the limiter caps and add some fuel so the saw doesn't run too lean. Echo seems to be more bent of pleasing the EPA than other makes. The vast majority of the Echo saws I've un-boxed and put in service here were so lean they would BARELY run until fully warmed up, and even then pretty "anemic" until the limiter caps were removed and correct carb settings made.......Cliff
 
Joisey

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My newest saw is an almost 20 year old Stihl HT75 pole pruner. That saw came with the limiter caps that somehow 'fell off', which benefitted engine performance all around. My other two saws are both Homelite, an XL-12 and an XL-2. I tuned all of these by ear, without problems. I have noticed a marked change in spark plug coating when I changed my 2 stroke oil about 10 years ago to Amsoil Saber premix oil.

Now there is no carbon on the plug shell and the electrode is an ash grey instead of a light chocolate brown. Mix ratio is the same as the oil that I previously used, Stihl and Homelite oil respectively.

Knock on wood, the XL-12 is still running original fuel hoses and has zero trouble with the new gasoline.
 
MacAttack

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Correct tuning is a big deal when it comes to 2-stroke power equipment. We continue to read about folks "smoking" P/C's on here, especially with Echo saws. This ONLY happens because the owner/operator is NOT taking the time to remove the limiter caps and add some fuel so the saw doesn't run too lean. Echo seems to be more bent of pleasing the EPA than other makes. The vast majority of the Echo saws I've un-boxed and put in service here were so lean they would BARELY run until fully warmed up, and even then pretty "anemic" until the limiter caps were removed and correct carb settings made.......Cliff

My dad has been buying up basically new gas trimmers at the local flea market from different guys that get them as customer returns and sells cheap, like $10, as non-runners. With most of them, literally all he has had to do to them is adjust the carb needles. They are being shipped with the factory settings so lean, they wouldn't even run. i have one of them, some kind of Homelite trimmer, richened up the carb and it runs perfect.
 
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