How to make your own air box lid pre-filter (step by step)

**maxfior** · 07-28-2008, 09:14 AM

Originally posted by Speedy 400ex
it still bogs off idle even with the 42 pilot. so im confused in what i need to do to fix it. also the thing heats up really fast.

• What is the needle position?
• What main do you have installed?
• Is filter clean and oiled properly?
• What did you set for fuel/air screw? 2 1/2 turns out to start?

The engine should heat up pretty quickly, esp. in the summer time; my engine gets HOT to the touch (middle part of the jug) within 1.5 minutes sometime less… Do you have a after market pipe installed? You won’t have to jet too much from stock if you have the OEM pipe on. Let me know.

EDIT: I see you have a slip on. #155 and #40 or #42 should work with your pipe. How is your plug? Does it run okay past idle? How is WOT?

Max

**Speedy 400ex** · 07-28-2008, 09:46 AM

I dont know about the needle position, where do i chainge that? i have a 155 main in there. it idles well but it bogs when i punch it but if i roll in to it I can get to WOT which feals good. i dident tuch the fuel air screw. Im going to go get a socket that fits today.

**maxfior** · 07-28-2008, 10:08 AM

Originally posted by Speedy 400ex
I dont know about the needle position, where do i chainge that? i have a 155 main in there. it idles well but it bogs when i punch it but if i roll in to it I can get to WOT which feals good. i dident tuch the fuel air screw. Im going to go get a socket that fits today.

Sounds like you have a pretty good attack plan. Check the plug and also check the fuel screw out. You'll have to pull the carb or move it to the side to get access to it. Turn it all the way in (tighten lightly) then back it out 2 and 1/2. After that, you can check the needle; it's at the top, where the slide is. You'll have to pull the top of the carb and get access to the needle. Then you can make sure it's in the middle (if memory serves there are 5 steps, so you'll want to be in the middle. I know my 2005 has a fixed needle. I'm pretty sure stock should be in the middle. I'd check your fuel air screw before you rip in the carb more as it might be your issue. WOT feels good, so that means that your main jet is good. If the fuel air screw does not help you might want to try a different pilot jet. Let me know what happens.

Max

**Speedy 400ex** · 07-28-2008, 08:09 PM

well i just took the plug out and from looking in my clymer the plug is carbon fouled and one of causes was a rich fuel mixture. Is this just a matter of changing the fuel air mix?

**Speedy 400ex** · 08-14-2008, 10:35 PM

ok well i got it now i think. thanks for the help

**maxfior** · 08-15-2008, 06:25 AM

It looks like you are on the right track... dark plug could be air/fuel I would check the screw first, try 2 1/2 turns out. I believe that's what I'm running on my 05. Jetting sure can be a pain in the ares!

Max

**08Outlaw** · 02-25-2009, 07:43 AM

Want to thank Max for a great tip on the airbox!! I too love to save some $ and make my own parts! Take a look at the results on my 08 Outlaw 525s- and the resulting performance is awesome- the beast can finally breathe!!!

**08Outlaw** · 02-25-2009, 07:45 AM

more.....

**08Outlaw** · 02-25-2009, 07:47 AM

yet another....

**maxfior** · 02-25-2009, 07:48 AM

Originally posted by 08Outlaw
more.....

THAT looks REALLY nice man! Good work! It is a good feeling when you can make some stuff your self and save a few bones for other items, plus, stabbing the throttle and feeling the extra gained power is nice too!!!

M.

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