Am I running to lean now? (pics)

[maxamillion125]

The first 2 pics are before I dropped my main jet from 190 to 180. The bike pulls harder and revs out on top now, but am I running to lean now. Is it better to run it to lean or to rich. Before I dropped the main it was bogging and the powerband was really short and flat. Will turning the airscrew in help it run richer?

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[Ogener]

I actually like the color of the plug now, in fact think you could go a size or half smaller yet. The ideal color for a plug is a nice tan color, black is too rich and white or really light tan is too lean. So I think that you are okay. It is safer to run on the rich side of the jetting.

[dylans503]

you could turn the air screw in, but id only do a half turn or so, depending on how its jetted.

do you know what stock is?

go 1 turn out, then 2, then 3, and tell us which is making the most power, does the idle raise and drop when you play with it from 1.5- 2.5 turns out?

but about the main, it looks okay, but id do a plug chop test.

does it rev out all the way? or does it pop at all?

does it FEEL irratic? and scratchy/ throaty.

my kx 60 had a 175 main, stock was 200, and it sounded and felt waay to lean, but like its not getting gas lean not "holey hell this bike is out of control" lean.

but 4th gear id get tunnel vision from how fast itd accelerate. does it behave like that at all?

i say its fine though

[MotoXRyne]

Looks like you could still lean it out a tad more. Tan would be perfect, better to be slightly rich than slightly lean though.

[maxamillion125]

The idle doesn't really change when I turn the air screw from 1 to 2.5 turns out. Is this normal?

[greenguy500]

Are you doing a long high-speed run before shutting it off, or allowing it to idle back to the pits,camp before pulling the plug?

[mxn4life]

A proper plug chop is crucial to determining a proper reading.

Keep in mind that it is nearly impossible to jet a carb when a motor has lower than normal compression and expired silencer packing. When you repack your silencer and change your top end, this is the jetting procedure you should follow.

Properly jetting a carberator through the jetting circuits.

Place the needle clip in the middle clip position, and the air screw 1 turn out.

Make sure the float height is set to factory specs.

Turn idle screw all the way out, so that it's bearly touching the slide

Warm up your bike and preform throttle chops by holding throttle at 1/8, 1/2 and full.

Preforming a throttle chop procedure.

Place the bike in a given gear and dont shift. 1) Hold the throttle at 1/8

begin exceleration let rpm's peak. With clutch hand hold the kill switch keep the bike in gear and coast intil you come to a stop. pull and read the plug.

If plug reads rich back air screw 1/4 turn and repeat the plug chop procedure.

When you get to more than 3 turns out, change the pilot jet to one size smaller. Reset Air screw to 1 turn out and continue backing the air screw out 1/4 turns at a time. Continue plug chop procedure.

When the plug reads a golden brown color, you are done jetting the slow system "pilot circuit".

Preform the plug chop procedure, with the throttle wide open. Read plug, if rich drop 1 main jet size. Continue plug chop procedure.

When plug reads a golden brown color, you are done jetting the main system

"Main circuit".

Preform the plug chop procedure with the throttle half open. Read plug, if rich raise the needle clip position 1 position at a time. if lean lower clip position 1 at a time. By now the throttle should be crisp from begining to end.

When plug reads a golden brown color, you are done jetting the needle/ transition system. " needle circuit".

The needle controls the transition between the pilot and main jetting circuit.

Fine tuning Via idle screw and air screw Last step, turn the idle screw in so the bike idles at it's lowest. Turn idle up just to keep bike runing.

Your done, make sure to check plug at every atmospheric change, Temp Alttitude ect.

[juliend]

I've always been taught that the color of the tip of the plug is pretty much good only for leading you astray. You can get an idea of the plugs running temp and such, but you won't learn much in the way of fuel/air mix. A real plug chop is cutting the threads off the plug and reading the burn ring at the very base of the insulator. You must do this after running a fresh plug in a warmed up engine and run ONLY at the throttle position for the carb circuit you wish to read. You can't see the burn ring in your pics at all, so it's impossible (imo) to benefit from trying to read that plug from here. It's only evident that the running temp of the plug has increased from whatever changes you made.

If you do a plug chop, you'd follow the instructions above from Mxn, and then chop the plug and read the burn ring. About a 2mm thick ring with a nice brown mocha color is great. It's rich enough to be safe over a pretty good range of temp/elevation changes from where you're testing. If you went down to the coast from the mtn's you'd obviously need to re-jet. Brown and a little more than 2mm is ok and safe, but if it's much darker (black) or larger then you're getting on the rich side. If it's light colored and less than 2mm and you're too lean on whichever jet you're checking unless you're going for absolute max power.

That's my 2 cents anyhow, and the way I read a plug.

[maxamillion125]

Thanks for the input guys, good points!