whats the deal? DRZ400sm 2008

My bike seems under powered. I have a two brother slip on, stock header, 3x3 mod, jd jet kit (4500ft elevation-blue needle, 3rd clip, 155 main, had to install an 20 pilot due to fuel mixture screw not having an affect, and a thumper talk extended screw) K&N filter and 38 rear sprocket with a 15 front.  I get around 52 mpg average. No matter how hard I try theres no way I can ride a wheely. Thinking it was operator error I gave up. 


Until I rode my buddies 2005 drz400sm with full yoshimura rs2, 3x3, dyno jet kit, 38 rear and 15 front as well. states he's getting 80-90 miles to a tank. And 1st through 3rd wheelies were easy as pie. Its really hard to think a header pipe would add that much torque???


So im stuck at should I spend 450 on a full yoshi pipe to enjoy my bike a bit more?? am I running the wrong setup on my carb? I had to drop the pilot to a 20 because the fuel mixture screw with the stock had absolutely no change. I now have control with the smaller jet. Should I get the keihn fuel screw and go with a bigger pilot jet thinking my screw is damaged?

Edited by james7607

Yes a full exhaust makes that kind of difference. Along with the right settings in your carb. You are also running a gear ratio that is not wheelie friendly if power wheelies are your thing.

What's you elevation and currant jet kit brand?

Its a jd jet kit. I'm currently at 4500-4600ft elevation. I know its not wheelie friendly and i enjoy the more toped but I'm just stumped on how another bike with nearly the only difference being a full yoshi. His bike had 15-38t as well. 

I ride at about the same elevation and higher. The JD kit recommends the red needle at that elevation. I did the 3x3 and rejetted the stock carb following the directions in the JD kit.

I have not installed the MRD/SSW exhaust yet (anxiously awaiting its delivery) but I noticed better throttle response and more power throughout the RPM range. Leads me to believe I have the carb set up correct (proper fuel curve).

Physics still apply; If you set up the intake to allow more air/fuel in you also have to improve its way out (exhaust). The only way to get the full effect is a full performance exhaust system.

Hope this helps...

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