Don't change WR 426 to YZ timing

For all you wondering if the 01 WR426 is improved by changing the timing to YZ settings, forget it. Just changed mine with no other adjustments to the bike and there was no noticeable improvement. Still pulls strong top to bottom...just like before. Maybe carb abjustments mentioned by Dean will help: I'm waiting to hear and try. But otherwise, I'd suggest fellow 426ers enjoy what you've got in the stock bike (w'out air indiction restrictor and baffle, trimmed throttle stop). As a former pro mx'r tuned dual sporter I like extra power too so don't think I'd miss an improvement if it were there. My previous scooters were 98 400YZF and 99 250YZ. This 426 blazes!

Parry in Clovis

Doesn't look like it to me.

On my 2000WR the stop was on the back side of the round linkage where the cable attaches. Not very visible in this picture.

I went in from underneath with a 3/8" drive allen socket and a universal joint and extension. That made it a snap.

The carb you showed is from a 2000 WR - the throttle stop is in a different place on the 2001. If you take off the rear subframe, and loosen the carb so that you can rotate the top of the carb to the left, you'll see the stop on the right side of the carb under the throttle linkage. On the 01WR the screw is in the open - no disassembly of the carb is needed.

There are several good write-ups if you do a search.......

Parry in clovis

your the first person i've heard from who said he couldn't tell the difference.

try turning the camshaft one tooth clockwise, it's brilliant when you've done. far better than 'bench racing'.

seems to me you didn't moe it at all. DH!!!!

Taffy

Parry,

Just to make sure, confirm your running the exhaust with no baffle, along with the airbox lid gone and the throttle stop cut? After I changed to YZ timing and before I rejetted the most noticeable difference was a reduction in engine braking. It was a huge difference that was very obvious going down hills. Did you experience this? Even before I rejetted, I did notice more midrange hit but after changing needles it became much more noticeable.

Brad

PS

The throttle stop on the 2000 and 2001 models is the same and is in the same location. It was different before the FCR2 carb. Other than a jetting change and possible accel. pump differences, the carbs for 2000 and 2001 are identical. The throttle stop is #58 at the following site:

http://216.37.204.202/Yamaha_OEM/YamahaDB.asp?Type=13&A=162&B=35

Brad

[This message has been edited by Brad (edited 01-21-2001).]

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