spark plug pics,lean or OK ?

Hi guys as some of you will know \I've been chaning main jets in my race bike. It was running lean with dynojet 140s so i went up to mikuni 152.5s. Since then I've done a track day at Cadwell on the 1st of Sep. and now my plugs looks like this see attached. I'm thinking it could still be a little lean.
I have some 160s.

What do you think ?

I've got no money for dyno time. and the bike isn't road legal.

The pics make it look a bit green ... but if it is light brow/grey then I'd say that was absolutely fine (if not a little rich as the plug threaded but looks slightly sooty) ... if it starts to look more white than grey, then up-jet ...

yeah, it's got a shiney apearance. It has got a green tinge to it.

Originally Posted by boo86

yeah, it's got a shiney apearance. It has got a green tinge to it.

What fuel are you using?

super unleaded. I think it's 97 RON.

Originally Posted by boo86

super unleaded. I think it's 97 RON.

Ah, that'll be the green then .. the super unleadeds have all sorts of fruity additives in ... I wouldn't like to say what colour they would turn the plug!!

Bring back good old 4-star I say ... you always knew where you were with plug colour and 4-star!!

Those plugs look fine to me. I would say it's running fine. I suppose when it's track use it can mean a big difference tho

Linky to spark plug pics:

http://home.wanadoo.nl/xavira/sparkplug/spark2.htm

Chin

You can't really tell much by just looking at the tip - you have to look at the insulator right down inside. And you can't tell much without knowing what the grade is and whether you 'chopped' it at peak revs or not. If you didn't, the risk is that you are merely looking at what the fueling is at part throttle. And finally, you can't tell anything at all from the body: that's only running at cylinder head temperature - about one seventh of what the insulator and electrodes are running at.

Start with: "does it feel that it is down on power or misfiring at max revs?"

[rowdy]

How does the bike feel , does it feel as if it lacks power or does it run ok, this may be a useless piece of info to you as my bike has FI but when my bike was dynod the fella that done it leaned it off a bit because he said they went better that way. He is the co founder of dynopro and was responsible for testing the bikes in mini twins at race meets so I kind of trust what he said, but he could be wrong.