matt400ex
10-22-2003, 12:26 PM
Hi all. My 2000 400ex has me confused on what I'm doing wrong with the air to fuel mix. I've been racing it the past couple of months and its ran GREAT! No missing at all, and I've been able to keep up with everyone. I'm running a FMF silencer with the disc's and cap on the back. I'm running K&N's power kit on stage 2, with a 165 main jet, and the pilot jet is a 42, and I have a K&N filter with some small holes drill in the air box lid.
Now my pipe has always been covered with sut, or carbon. Well when getting ready for this weeks race, I noticed my grab bar and number plate were black too. I pulled off the seat, and found my air box was smashed in on the bottom, and my filter was covered with mud. (did this a few weeks back "bottoming out") My air box supports have been broken since I've owned the quad and the box has always sagged down.
Well, I patched the hole on the bottom of the box, raised the box back up to where it should sit, and reconditioned the filter. Now the quad runs like crap. It is missing out in the low to mid range. It idles fine and pulls O.K. up top. I checked the plug and its look good, with very little carbon build up. I've tried running with the air box lid off and it only seems to bog the bike down (always has).
So my question is, if I'm not getting enough air, why does it run worse with the lid off. The bike actually ran better trying to breathe through a dirty air filter. My main jet isn't all that big, and I'm sure the mixture screw is turned out the 3.5 turns it should be. I'm sure the problem is simple, I just can't seem to put it together. Thanks in advance for any help!!!
Matt
Now my pipe has always been covered with sut, or carbon. Well when getting ready for this weeks race, I noticed my grab bar and number plate were black too. I pulled off the seat, and found my air box was smashed in on the bottom, and my filter was covered with mud. (did this a few weeks back "bottoming out") My air box supports have been broken since I've owned the quad and the box has always sagged down.
Well, I patched the hole on the bottom of the box, raised the box back up to where it should sit, and reconditioned the filter. Now the quad runs like crap. It is missing out in the low to mid range. It idles fine and pulls O.K. up top. I checked the plug and its look good, with very little carbon build up. I've tried running with the air box lid off and it only seems to bog the bike down (always has).
So my question is, if I'm not getting enough air, why does it run worse with the lid off. The bike actually ran better trying to breathe through a dirty air filter. My main jet isn't all that big, and I'm sure the mixture screw is turned out the 3.5 turns it should be. I'm sure the problem is simple, I just can't seem to put it together. Thanks in advance for any help!!!
Matt