Plug checks when jetting

[edz250r]

When you guys change a jet and then change your plug to check for lean/rich, do you put a new plug in, immediately do a WOT run and pull it or do you first do some normal riding for a bit and then do a WOT run?

The reason I ask is because my quad has been bogging out on top (ie: rich) and the plug was black when I pulled it. I put a new plug in without even dropping a jet size yet, started it up and made a WOT run without doing ANY riding, stopped, pulled the plug and it was dry and almost as white as it was when it was new. I'm just wondering if a new plug will change to the color (ie: chocolate brown) if it was only used for a 6-8 second run without any riding beforehand.

Sounds like its VERY LEAN.

too much air and too little fuel in the WOT position. The first plug might have already had residue buildup from previous runs.

Suggest you richen it up and try again.

[YFZRob]

It sounds like you're not properly reading the plug. The part you see just at a glance is NOT the part you should read. That section takes a bit longer to change color. You have to look at the BASE of the porcelin...and I mean the base....way down inside the plug. The base will develop a ring of color around it...this is what you read. If you cannot easily see it, hack saw the threaded section of the plug off so you can, like this...

http://www.looseboltsmotorsports.com/images/atv/NGK0005.JPG