Someone please help !!!!I just installed a Weisco 440 kit in my 400ex .It has a stage 1hot cam ,slight port job ,K&N filter Scorpion muffler ,with stock head pipe .It has a 155 main ,and stock pilot jet,withthe needle clip in the middle position .Air screw is turned out the stock 1 1/2 turns .It seems to run well from idle to just over half ,but then pops ,sputters ,and will not rev up ,and sometimes backfires with flames at higher RPM's .What do I need to do with the carb ion order for it to ruin decent ???PLEASE HELP !!! Thanks[img]i/expressions/face-icon-small-disgusted.gif[/img]

 

I run a 185 main jet in a stock carb on my 440EX. The spark plug is always a light brown and I have yet to foul a plug in 2 years of use. Your machine needs more fuel.

 

Thanks buddy ,I really appreciate it .Will do .So the clip on the needle is good in the stock position ?

 

I run a 180 main in mine and a 42 pilot jet... runs great. Yes the stock position of the clip is fine.

 

Thanks much .This kit was just installed ,so am I gonna notice a pretty substantial diff with this 440 ??It was a pretty fast quad to begin with ,in fact Im recovering from surgery on my knee after tearing it up(my knee) down at the Oregon sand dunes when it was just the 400ex .So I figured I might as well make it quicker so that I can tear up my other knee...Right !! Ha,Ha. Im just hoping it was worth the $500.00 bill .Are you happy with the 440 ??

Thanks a lot ,

 

440 Kit is a thing of beauty, getting the carb to run perfect with it, a task in a half never will it be perfect off the stock carb upgrade the carb or play with jets and settings on the carb, also if its popping and that it means its not getting enough fuel, if you have a fuel filter take it off, check your gas cap to make sure it still releases pressure and takes in ( more or less suck and blow on the hose connected to the gas cap, after picking yourself up from the floor from gas fumes you'll know if it works)

 

Hey ,thanks for the great info !!Carbs have always been kind of a mystry to me .This is the first 4 stroke that I have ever owned .Things just seem to be a little bit diff on the the 4 strokes than the 2 strokes .
So in essence you are saying that I can still make the stock carb work ,Im just not going to get the full potential of my new 440 kit out of it ?? Thanks in advance .

440LW

 

I ran the stock position for the needle and it runs fine. Later on I switched the needle to one level difference to make it richer (I can't remember if that is up or down, I believe it is up). I didn't notice any difference, but I would much rather run a little rich than lean. I ride Dumont and the 440EX will take Raptors and Predators with pipes, etc. with ease on Comp Hill. Enjoy your 440, I know I do!!

 

Cool ,I heard Dumont is just awesome!!! Id like to make it out there one of these days .I think Ill leave the clip in the stock position ,and bump up the main to 180 ,or 185 .I can't wait till my knee heals so that I can go test it out .Thanks for the info bud!!!

440LW

 

Make sure to put the 42 pilot jet in your carb... it make a huge difference in the way your bike starts.