just got done experimenting with my new mods and was a little dissapointed at first. got my plug lookin nice and brown but couldn't get it to quit sputtering under full throttle at high rpms and it started getting a little warm under load . i just pulled the foam pre-filter off the airbox and hosed out my dirty radiator and now she screams. wow what a launch. that initial burst of speed is awesome. overheating problem went away also. i think she still needs more air though. i have a drop in k&n. do i need to adjust the air fuel needle to correct this problem?

 

Give us the scoop on how bad it will smoke your 600[img]i/expressions/face-icon-small-wink.gif[/img]

 

If your already rich you shouldn't need to rejet. just be careful and look for signs of leaning out. I was totally dialed with the stock airbox and pulled my airbox off and put a k&n clamp on filer on and it was too lean and I melted my pistons to the rings. but in your case with being on the rich side anyway you should be just fine. with the airbox on mine I was just at the point where I just a hare from being too lean on the top end for max power.

 

i'm good on the jetting, it was recommended i move the needle clip down one spot but my first plug was black so i moved it back up and nows it's brown. i'm not getting enough air and i can't leave that plastic snorkel off cause my seat won't fit right. do i need to add some inlets to my airbox?

 

yes,they need a lot of air when you put pipe on it,especially the explorer 400 is in more detuned state than the scrambler,so let it breath,if you don't care about the airbox,put a k&n filtercharger on it and it will deliver what the pipe need for max output,i remember when i first trail modded my 400 back some years ago with airbox,she was sputtering like
$hit all over the throttle and once i removed the $hitty airbox,
the thing came alive like it should,at least try it if you don't mind
especially with the porting you have done to it,it will add more power
through the range for sure,trust me on this one,a bigger main will be needed as well but a trail mods tend to be leaner in the midrange.