I ride the LPNF and other stuff in the area every weekend.
See my 'Krannies just right ride thread' in the CA section.
Yea, first time at Gorman. To be honest, after seeing the number of goons at the gate and in the parking lot, we considered turning around. But once we got deeper into the park, the riding was quite good, especially the blue square/black diamond trails. The "walls" were are joke though, especially compared to the 500 hill or even the sand hill at jawbone. My riding buddy didn't like the 120/east fraizer trail, so we turned around way too early there. Typically my favorite spot is Ballinger. I'll check out your thread.
If you want more off-idle throttle response and torque at lower rpms, you don't want a YZ header. That decreases back pressure, and increases flow only at higher rpms.
Advancing the timing helps to get back the response down low. You can do it at the stator pick up or, put in a Dynatek ECU.
So does a leaner needle. The stock 2006 YZ needle works great. You can prove this by dropping the needle you have two positions, to feel the change.
You can get to the needle by taking off the tank and nothing else, and rotating the carb back and forth to access the allen head screws on the top of the carb.
Adjusting your TPS to spec also helps.
Have you done the gray wire mod yet?
Blocked off the ACV system and changed the Pilot air jet? That helps a few percent.
Removed the backfire screen? (requires a switch to non-flammable filter oil like NoToil)
I ended up with an 06 yz header for $50 shipped off ebay. I read the 08-09 was too big (i think 42-45mm) to offset the corked up stock muffler so I passed on the CL one. When I measured the 06 yz header, I got an ID of 40mm, which is consistent with other posts here. I think the WR header is 38mm, but I'll measure it when I'll pull it to be sure. Anyway, the 06 header is just something to experiment with.
I also purchased a pair of 06 yz cams from a fellow TTer, which are in the mail, arriving Monday.
Hmmm, I've been meaning to look into ignition timing more. Hadn't heard of changing the timing at the stator pick-up.. I've read on the YZ forum here that they'll swap out CDI's to the '06 (or even 03-05) to get a little better response down low. I suppose I couldn't do that with the WR? Dynatek is probably out of my price range.
I currently have the JD red needle and have been pretty happy with it. How would the 06 yz needle (NFPR) compare? I've already done your recommended pumper mods (honda diaphragm kit, tokyo mods spring, #50 leak jet) and currently get just over a 0.5 second squirt. I am quite pleased with the results from the pumper mods. I have a #40 leak jet that I plan on trying out next time I pull the rear subframe (putting that air boot back on gives me nightmares )
I'll check the voltage/resistance of the TPS next time I'm in there. I haven't had any of the surging/etc issues I read about being common to these bikes.
Gray wire mod is done
ACV & pilot air jet (#70) are stock.
Backfire screen is stock. I run no-toil oil, but I am extremely disappointed in their filters. I've had two of their filters disintegrate at the seams after one wash.
Overall, the 07 yz exhaust cam alone was a big upgrade from mid to high RPMs and is an absolute blast to ride anywhere that is not singletrack. For ST, it's OK, but the WR exhaust cam was better - I could lug around in 3rd gear and have enough power to grunt it out. With the yz cam on ST's, I'm not fast enough to be in the powerband of 3rd, so I'm constantly battling not having enough power and engine braking in 2nd.