i just got a kfx 700 it has a full dual hmf exhaust and it runs great but when i first start it and i give it a lil gas 2 warm it up it wants 2 die but if i give it full gass its ok , whats your thoughts on that? and anotherthing when im ridin it, its allgood untill i let off the gass and it backfires a lil any ideas why thats happen?

 

Sounds lean. Was it rejetted for the aftermarket exhaust?
Try using a little of the choke lever to richen it up and see if the problem is still there. If the backfire stops, you'll need to go to a larger main jet.

 

Budman is right.......poping on de-cel is an indication that it is lean and the jets are probably wrong. If the person who had it before you did not re-jet the carbs then you need to do it. Any time you add an exhaust...more air out.....you need to rejet...more fuel in. Should be a simple fix.

 

yea my kfx700 used to do that to!!!the only difference is i got dmc alien pipes but all and all the same just go up on main jet!

 

thanks for your guys help !!!!!the guy that had it before me never changed the jetts !!!!so i got the right ones now im puttin them in this weekend i hope it takes care of the problem thanks again!!!!