I have an 02 Trailboss. I have an Aaen megaphone muffler,green primary, K&N, and jetted from a 120 main to a 125. My problem is reading the spark plug. I put in a new plug and did the WOT run. The plug itself is blackish, but the tip of the electrode and the tip of the insulator are both a grayish color. I'm afraid it's running lean at certain throttle positions. I put the stock air filter back on today for the time being. I'd say the K&N is the culprit(if it is lean). My question is, what do I do if it is running lean on the low end? Can I richen it up with the pilot screw, clip position, or pilot jet. I'm pretty new to the Carb thing and any tips would be greatly appreciated.

 

Make sure the bike is warmed up and then ride for about a mile. Do not run wide open! vary the throttle, open it up every now and then. You will not hurt anything as long as you vary the throttle. This will allow more gas and oil to enter without running too lean. After you do this then check your plug. I changed my jets and checked 4 or 5 times then took it to the local mx track and checked it after about 20 minutes and it was perfect for me. It should be a chocolate color. I personally didn't see the true chocolate color until after I rode it on the mx track. Until then it was a light chocolate but, after the mx it was a true chocolaty color. You will have to check it often until you are satisfied that the jets are right for you to feel comfortable so that you don't feel like you have to check all the time.

 

Where is the needle clip now? Move it down the needle a couple of notches and try it. When at idle, adjust the pilot screw until you reach the highest idle. Open it another 1/4 to 1/2 turn after that. When adjusting the needle clip position, go to one extreme or the other at first. This way you make an easily recognizable difference, and learn the reaction to both.

Jetting seems like such a pain when you're doing it. But when finished, it's well worth it.

 

Brent, this is all fine and dandy, but I don't know the first thing about the needle clip. I've just read alot of posts about it. Anyway, wouldn't it be best to try one thing at a time? What should I try first? The pilot screw? I need to turn it clockwise to cut down on the air, right? I think what I will do before I try anything else is take it for a good ride. I may not have even gotten it hot enough to get a good plug reading. I really don't see why a muffler and air filter would make such a difference. Aaen told me that I shouldn't need to jet, but the plug was definately not brown, so I jetted. Now, the plug doesn't look much different at all and I went up 2 jet sizes. It runs like a scalded dog. I can easily stand it straight up on a wheelie, where before it wouldn't wheelie if I stood on the back rack.

 

If it runs so great, don't worry about it.

 

Just because it's running good doesn't mean it's not lean. Infact that is a characteristic of a lean engine, they run great, but the piston runs hot.

 

Hey MM84, How's that Randy ratio doing this year???

 

Maybe you should be giving me advise.

 

What started out as a friendly conversation is for some reason sounding more like an argument, and I don't know why. I'm not looking to argue or sound like something I'm not. I was just stating something that a few mechanics have told me. I'm no mechanic, and I didn't mean to sound like I really know what I'm talking about. That's just what I've heard. Didn't mean to offend you or anything.........As for the Randy ratio, it was stupid from the get-go, and I think it's the main reason they haven't won a game......... Oh, by the way, I don't come in here to talk about football, there are forums for that also.

 

Just a friendly poke between river rivals. I support the Pack but live in Mn. Catch a lot of he!! for it too. Saw the name an' couldn't resist. Anyway enough about f-ball....