I know this topic has been covered, and I did searches so I wouldn't have to bug you guys unnecessarily, but I couldn't really find the answer to my question.

I have a 2001 400EX, just put on my new White Bros. E-Series pipe this morning, kept all 12 disks in it. I ran it with the airbox lid on and off, and couldn't tell a difference. It seems to run just fine either way. At this point I don't really want to make airbox modifications, and I don't want to rejet if I don't have to.

Am I missing out if I run it this way? I ride trails and track, and dunes, and I just don't want to mess with it all the time. What do you guys think?

Corry

 

Pull the plug. If its white-then yes up the main and possibly pilot jets a few sizes. If its brown then no don't touch it. I don't think theres any way it would be black so it isn't rich. Let us know how the plug is.

 

I would agree!

 

Here are 3 links I found that should tell your everything you need to know about it. It helped me out alot.
Tuning your E-series

How to "Read" a spark plug

Quick Jetting guide

 

i'm taking it out in the am - I will let you guys know about the plug when I get back. Thanks for the links, and the help!

 

OK - this is interesting. I took my quad out this morning, but before I rode it I pulled the plug and checked it. Black. On the top, where the gap is. The bottom is all white. But I think it's been black - before I put the pipe on I had pulled it once and the top was black like that. What's that mean?

The only thing I can think of is I ride at high elevations sometimes, like 7500 feet, and I didn't rejet....maybe that turned the plug black?

And, I ran my quad through all the gears this morning, and tried to hit all my rpm's, and it didn't miss at all or backfire or anything. Ran like a top!

So...I am tempted to just leave it alone......is that OK?

 

Corry,
My guess is that you are a little lean. Put in a brand new plug, get to high rpm and hit the kill switch and do a plug read. My guess is that it will be on the white side. That may be perfect for the Cinders, though...

It is interesting that your air box lid did not make any difference. Are you using the stock foam filter?

Clark

 

Hi Clark! [img]i/expressions/face-icon-small-happy.gif[/img]

Yeah, I am using my stock foam filter, with that sticky filter stuff on it, too. I expected the lid off would make a huge difference......hmmmmmmmm....

I bought a 142.5 main jet to take with me to the Cinders just in case I need it. I don't want to sit around while everyone else is riding! I also bought a new plug - so I will do the plug test! I need to check the porcelain part of the plug - right?

Thanks for the help, guys!

Corry

 

i have a 2001 400ex and i have and e series slip on and a k&n air filter and i rejeted mine to 152 stock is (148) so if your just doing a pipe i would say no you wouldnt have to rejet (as long as its running alright)

john

 

Yeah, I think you're right. I called White Bros. today, and talked with them, too, about reading the plug. The guy I talked to said that taking plug readings is hard to do accurately these days with all the different additives in the gas, etc. He said the best way to tell is just to ride it, and pay close attention to if it's heating up quickly or not, or missing, etc. My guess is, if anything, I'm running a little lean. I'm taking it out to the track in a couple of days, and I will be able to tell out there if I am getting the power out of it that I need.

Thanks again to those of you who responded to this post. Your help is always appreciated. Maybe one day when I am wise I can return the favor! [img]i/expressions/face-icon-small-wink.gif[/img]

Corry