I have just recently taken the s/a out of my Z250 and it ran great if not way better than before when it was in but I took my airbox lid of and it ran like $hit and I mean that it was studdering falling all over itself and everthing! But before I took the s/a out it would run fine with the airbox lid off. Do u think it is running to lean or just right? No backfires and it hasnt overheated or anything on me so... Is reliability a factor?

P.S dont mean to sound like a worry wart but first quad and everthing...

 

When I 1st got my Z, before I knew much about ATV's, I took the airbox lid off and was impressed with the sound, but when I road it... it ran like royal crap! At the time I didnt know why, and just wished I could leave the airbox lid off, but for some reason couldnt. Now I have learned that when you take the lid off you need to jet up a size or two, so thats probably what the problem is.

 

I know I need to rejet with the airbox lid of now that i have taken the s/a out . But before the s/a was out I didnt have to refet it ran fine. My question is that is the s/a being out with the airbox lid ON making it run to lean?

 

You need to look at your spark plug, is it white, then you are running way to lean! If light brown, that is what yah want it to look like[img]i/expressions/face-icon-small-smile.gif[/img]

 

Yes. Thats why you would need to jet it [img]i/expressions/face-icon-small-smile.gif[/img]