Fuel Mixture How does my plug look?

[SkyenX]

Hi everyone, not too sure what I'm looking at, or how to read my plug.

Engine was running rich with a dark black, sooty plug, so I leaned out the carb and here is what the plug looks like now.

Matte/chalky appearance, no soot, and an ashy/light brown insulator. Am I running too lean/hot?

Thank you!

 

[GreasyChris]

That looks pretty good. How's the bike running? Is it 4 stroking ? Boggy? If it's running good and the plug looks like that then that's pretty good. Could maybe go a touch leaner.

 

[SkyenX]

Bike is running very well, ran 35mph on a flat, everything stock. No bogging, very responsive and no 4 stroking as far as I could tell. Engine was screaming though, and making some knocking noises at those speeds. Could that be pre-ignition?
Took it for a run 20 minutes ago and now oil seems to be weeping from around the spark plug.

P.s. carb needle is on the leanest setting

 

[GreasyChris]

It wouldnt hurt to make sure all the bolts and nuts are tight. They have a habit of loosening off especially if it's a newer engine. Make sure the spark plug is tight. The weeping could be a bad seal on the plug or crappy casting on the head or the plug isnt tight. Sounds like you have it running good. Not sure about the knocking noise could be pre ignition or even a lean misfire. Try lowering the clip 1 notch and see if the noise is still there and how the performance is.

 

[CrazyDan]

That plug looks great. You can use teflon plumbing tape on the spark plug threads to get a better seal.

 

[SkyenX]

That plug looks great. You can use teflon plumbing tape on the spark plug threads to get a better seal.

Thanks, thats a great idea, I'll try that! I'll see if there's some made specifically for gasoline.

 

[SkyenX]

It wouldnt hurt to make sure all the bolts and nuts are tight. They have a habit of loosening off especially if it's a newer engine. Make sure the spark plug is tight. The weeping could be a bad seal on the plug or crappy casting on the head or the plug isnt tight. Sounds like you have it running good. Not sure about the knocking noise could be pre ignition or even a lean misfire. Try lowering the clip 1 notch and see if the noise is still there and how the performance is.

Thanks Chris, the head nuts were a little loose so i snugged them up. Noticed oil was weeping from the bottom gasket before so hopefully that fixes things. Clip was already one lower from factory and that was too rich. Attached is a photo of the same plug on that needle setting from before.

 

[SkyenX]

I'm worried that the bike might be running TOO lean now and I don't want it to overheat, what is the best way to check for this? Bogging?

 

[gary55]

I'm worried that the bike might be running TOO lean now and I don't want it to overheat, what is the best way to check for this? Bogging?

Where ever you had it set when the plug was a chocolate brown leave it there. That was perfect.

 

[SkyenX]

Where ever you had it set when the plug was a chocolate brown leave it there. That was perfect.

In those first three pictures? Yep that's what I have it set as currently, those are the most recent pictures. Thanks for the help