AIS kit jetting too rich?
Posted March 06, 2008 - 02:14 PM
I ride a 07 wr450 in Southern cal 1000'-7000'. I run the stock pipe with the inner most baffle removed (the one that need the rivets drilled out to remove).
Posted March 06, 2008 - 05:46 PM
Posted March 06, 2008 - 06:36 PM
Posted March 07, 2008 - 07:32 PM
Posted March 08, 2008 - 09:29 AM
Posted March 08, 2008 - 09:44 AM
do you mean move the clip up (lower the needle) or move the clip down (raise the needle)?
Moving the clip towards the flat (flat/top of the needle) to lean (lower the needle) as you go up in altitude. Less air density = Less fuel needed.
Posted March 08, 2008 - 10:52 AM
Below are my comments on your jetting issue. They are excerpted from an earlier discussion thread on this same subject.
What follows is the excerpt from the October 2007 Dirt Rider 450 shootout article entitled 2007 450 Off-Road Comparison: "Making the Yamaha Run. It is pretty easy to make the WR go from snore to score. Just buy the GYTR kit (GYT-5TJ93-69-01, $49.95) that includes the shorter throttle stop, a block-off kit for the Air Induction System (AIS) and a set of jets that bump the power by richening the jetting, then follow the included instructions. This is how we tested the bike in Costa Rica for its debut and in our first test. But in light of current standards and enforcements here in California, we also came up with the setting that we tested the bike in for this comparison. We used the shorter throttle stop, took out only the smallest stuffer from the muffler and removed the restrictor from the top of the airbox. We also disconnected the gray wire at the six-pin connector underneath the left sidepanel. We left the stock jetting in the bike and did not mess with the AIS, as it has no performance effect on the engine aside from causing the lean popping noises inside the exhaust. With this setting, we felt the bike was more ridable and smoother in the smaller throttle positions than the GYTR-jetted bike, and it got better fuel economy. Plus, it ran better at elevations above 7000 feet."
Finally, leaving the stock jetting alone as mentioned in the article would seem to imply that the stock needle was not changed. However, I would still get rid of the AIS, if you want to go with the Dirt Rider recommended jetting, because listening to it pop is annoying and may cover up a lean jetting problem.
Finally, finally. The SEARCH function is a great tool on Thumpertalk.