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JustinBoots
08-15-2009, 11:23 AM
I'm new to sport quads and just bought a 2003 Suzuki Z400 Quadsport. When I got it it ran awesome, but when I went to do some maintenance, realized there was no air filter element or airbox lid. It was running totally open. Well I ordered all the new parts and put them on and now it is starved for power, popping and sputtering in first gear after about 1/4 throttle. I drove it back in the shop and took out the air filter and it was running like a scalded ape again.

My assumption is it's running too rich now that it's getting less air.

Question 1: Is my assumption headed in the right direction.

Question 2: I can't seem to find the fuel mixture screw on this carb. Can anyone point me in the right direction? I do have the idle control screw visible, but looking for that fuel screw.

If I'm headed in a totally wrong direction, please let me know that as well.
knoxville9
08-15-2009, 04:23 PM
The fuel screw is on the under side of the carb towards the front where it goes to the motor inside a lil hole
hhaceesa
08-15-2009, 04:33 PM
hey i have a 03 ltz 400 i run a k&n filter with no airbox lid i dont know anything about screws or air fuel mix my bike is popping at high end of all gears but just enough to loose a little power
knoxville9
08-15-2009, 04:40 PM
Then you should undo your carb from the boots and spin it sideways look under it towards the front inside a hole in front of the bowl is a flat head screw turn it counter clockwise until it stops popping
JustinBoots
08-16-2009, 06:12 AM
Ahhh!!! I saw that 1/2" deep hole there and thought maybe that could be the spot.

Thanks
destey
08-22-2009, 07:12 AM
sounds like its further off than the fuel screw can adjust for.

What jets does it have in it?

I'm running a k&n with no air box lid, and an exhaust mod. I had to go to a 32.5 pilot and a 152 main. Stock it came with a 22.5 and a 130.
JustinBoots
08-22-2009, 08:01 AM
yeah I got it a little better with the adjustment, but still not what it was before the installation of the air filter. I pulled the carb and cleaned it, but didn't see a sizing stamp on jets. The port was much larger than i am used to seeing in other carb work I've done. I decided I'm not a race quad guy now and have put it up for sale.