E-Series Question Again

[Wheelie]

I got my E-series slip-on pipe last Friday and tested it all weekend and overall am happy with it....but.....the top end power is not what I was hoping. The low and mid range is incredible, but once the R's build it feels "flat" ? Does adding discs increase top end power, the modified stock silencer felt stronger on top.

I am running a modified airbox lix (the hole is about the size of the entire lid), modded stock filter (no steel mesh), lowered the clip on the needle one notch, and a 160 main.

Please help, need more power once the revs build, I don't want to go back to the stocker.

[Stunz]

Try a 165 mj.
You can also add more disk.

[skemp]

I felt like I had a nice power boost everywhere. If this flat feeling is happening at full throttle or close to it, your main jet may need to be changed. Both a rich and lean condition will give a flat feeling, but a rich condition will also blubber and feel like the motor is loaded up. A lean condition will feel like you are running out of gas, like the power is only there when the throttle is pegged. Your 160 main jet sounds good for the intake modifications you have, but when you add that pipe, it will lean things out a lot. I think you might be running lean on the main jet, but I can't be sure without riding it. You could try to go up a few sizes, and then ride it. Buy a couple new spark plugs so you can do some plug runs. In case you don't know, this is simply running at full throttle in the highest gear you can for as long as you can keeping the engine under a load and the RPMs not too high. When space runs out (or after about 10 seconds), hit the kill switch while keeping the throttle pinned and come to a stop, pull out the plug, and examine the entire tip for color. You want a light brown/tan color. White or gray is lean, and dark, dark brown/black is rich. Make the necessary changes to the main jet (bigger or smaller / richer or leaner), and do the same thing. It will take some time, but once you get it dialed in, it will run like it should.

You mention that as the RPMs build up it starts to feel flat. If this is just happening with engine RPMs, and not with throttle positioning, it probably isn't jetting.

After all of this, if it still feels flat at high RPMs, realize this motor wasn't built to put out its best power at high RPMs, but rather right around 7,000 RPM, so at higher levels, power drops, so this could explain the flat feeling.

I felt my pipe made a big difference everywhere, but since I don't usually have it wide open all the time, I might not notice a difference up top like you do.

A flat feeling 'could' easily be fixed by jetting changes, so try that if the flat feeling comes at 3/4 to full throttle.

Hope I have helped.

[400exRacerX]

the slip-on was designed for low-mid range and the full system was designed for mid-top.