ok it runs im just a little rich i think.

[Speedy 400ex]

Well i got to ride my bike on the new jeting this past weekend for two days. i recently had to rejet because of the air box mod i did using a stage 2 dyna jet kit. From reading the plug and riding if feals a little rich. Im wondering what i need to lean out.

Current set up
42 pilot(im going to remove the choke soon.)
the main jet is a 170.
the needle is on the 3rd clip.

pic of the plug

[Brauap]

It looks fine.. maybe even a little to lean. But thats just me.. some other people will prolly disagree..

[Honda#4]

That kinda how my plug looks, could be a bit browner though.

Originally posted by Brauap
It looks fine.. maybe even a little to lean. But thats just me.. some other people will prolly disagree..

x2. plug reading can be dificult. I know shell gasoline will make your plug look cleaner because of the additives. Is that hows it looks for what range in the throttle position? Was that a full throttle reading? mid reading? low end? idle?

[Speedy 400ex]

Thats from the idle to full. I rode it hard, at all speeds, i even toped it out. it got like 10 hours of riding. maybe ill go with it a little longer and see.

[leasureryan]

To hell with that plug reading......that is such an inacurate way of telling your air/fuel. If the bike feels rich bro......lean it out. I would say with just a WB slip on and a simple air box mod...a 170 sounds rich to me...from experiance. I would drop it down to a 168 or even a 165....see how it is, do another plug reading if it makes you feel comfortable. Ypu won't have to run it long to change the color, if it does at all. Like I said...I find it very inacurate, it's a good start, or round about yes....but. The true way to get it right though is with an air/fuel meter on a dyno. I know they aren't always available everywhere, but if you get the chance, flip the small amount of cash and get your jetting right. Mine cost me $55....

[MtnEX]

That plug looks good to me.

With that said, you really have to check it 3 different times with different plugs on the 3 circuits to get an understanding of where you are at.

I haven't done the 42 pilot jet myself, but I figure you're fat on the pilot.

A 170 sounds a little large on the main jet. If it feels fat, it may be. I'd have to guess your good color is coming from running it in the needle (1/8 - 3/4 throttle).

If I were you, I'd put a fresh plug in it and go on a 3/4-Full throttle run... then let it cool, then pull the plug and have a look. Then I'd go from there. If it's black, go down on the main some and check again.