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Bman11
04-09-2011, 04:37 AM
I have a new 2007 400ex. I put a motoworks pipe on and it runs like crap. Adjusted it so it wouldn't sputter under acceleration. Now it will stall if I let off the gas completely. How and where can I adjust it so it doesn't stall? Sorry for the noob question.
dave07ex
04-09-2011, 06:27 AM
Need more info. Aside from a slip-on, are there any other mods? If you didn't get the quad brand new, have the jets been changed? You posted that you 'adjusted it', what did you mean by that?
CJM
04-09-2011, 06:27 AM
Did you change the jetting for the pipe?
Bman11
04-09-2011, 06:50 AM
No I haven't changed the jets. Any recommendations? The only things we have adjusted were the small finer knob (idle screw) on the left side of the carb and the smaller screw right next to that I think that's the air fuel mixture screw.
dave07ex
04-09-2011, 09:14 AM
Search the stickies for the threads on jetting. Your questions can likely be answered there. You should probably decide what, if anything, else you plan to modify and then consider purchasing a range of new jets for your planned upgrade path. Jets themselves are cheap, tuning the carb is trial and error but definitely educate yourself before you go adjusting and replacing things.
Even with just a slip-on muffler you probably need to increase the main jet size and possibly adjust the pilot screw. Don't go changing anything just based on that statement. Take an hour or so to read the many posts on jetting. Good luck.
Bman11
04-09-2011, 09:45 AM
Will do thanks dave
kt1148
04-09-2011, 10:02 AM
According to Motoworks(when I called them about my slip-on) the stock jets in the 400ex were fine :huh . Right now I'm running 152/40 for jetting, but I've added more than just a slip-on too.Also, the air/fuel screw is on the underside of carb when mounted to the quad, it has a D-shaped head. I was able to move it with some small needle nose pliers.
Honda4LifeWes36
04-10-2011, 12:17 AM
My buddy hear the same thing when he called about changing jets. He had a Dr. D slip on and they told him to leave the jets alone.

We looked into it on the a couple sites, switched em up, runs a whole lot better now.

X2 on searchin the stickies.