Woooohoooo!!! Holy @#!$%!!!!

[Scott_V]

I bought an 04 NOS WR450 about a month ago. Took it out for a ride in stock form at Jones Creek, Washington. I was regretting my first fourstroke purchase. ? The bike stumbled, had marginal power, and had no tractor like properties that everyone talks about. ? I was kind've ticked and really wanted my YZ250 back even if I had to kickstart the darn thing on every hill I rode.

Long story short,

Bought a JD kit and installed it per directions.

Took out snorkle.

Installed GYTR baffle.

Installed YZ throttle screw.

Took the bike to Brown's Camp in Tillamook Forest yesterday and , this bike is a rocketship. I love the tractable power on long rocky uphill climbs. I couldn't kill the thing no matter how bad of rider I am. Nice long straight or an obstacle on the trail? A wack of the throttle carries the front end for a LOOOOONNNNNG way . The only thing that sucks is I know that tires and chains are going to be a very frequent purchase.

It's not perfect yet. I still have a half throttle surge/stumble. I was going to look at the TPS. I've heard that sometimes these aren't adjusted properly. Anyone else have the same issue and what did you do to resolve it? My jetting setup is a stock jetting except for a 170 main, JD red needle on the fourth clip. Zip-Ty fuel screw at 1 3/4 turns. Altitude was 1500-2000 feet, low humidity and ~ 70 degrees.

The exhaust note sounds pretty crisp in the offensive throttle positions hinting at a slight lean condition. I am going to fuss with the needle a bit. Maybe use the blue needle but I am curious to hear other stories about adjusting the TPS.

[MrBill1]

Yup thats the trick with the WR they are SLOW when you first buy them, but when you do the AIS removal kit mods the bike FLYS

[Turismo]

Drop the needle 1 clip to lean it off if you have the stumbles at 1/2 throttle.

[Rip Wheeler]

It's not perfect yet. I still have a half throttle surge/stumble. I was going to look at the TPS. I've heard that sometimes these aren't adjusted properly. Anyone else have the same issue and what did you do to resolve it? My jetting setup is a stock jetting except for a 170 main, JD red needle on the fourth clip. Zip-Ty fuel screw at 1 3/4 turns. Altitude was 1500-2000 feet, low humidity and ~ 70 degrees.

Scott, I'm close to you and I bought a 04 WR450F new also. Mine came out of Canada, so I didnt have to do any of the mods. But your jetting will consume too much fuel. I also installed the JD kit, ended up using the blue needle, position #3 and I started out with the 170 main (came with a 160 in it) and then itr ran OK, made lots of power, but range was greatly diminished. So I bumped it back to the 168, and now I ended up witht he 165. Runs great, good power. I tried to find something that would work well from about 3500 and lower. It does feel a bit lean when I start geting around 4500, but I just drive around it, knowing I dont spend too much time up there. Also, get a ZIP ty fuel screw, great for fine tuning on the trail. And the stock muffler is really heavy. I use an FMF Powercore4 witht he quiet core insert and its 93 db, and will give you lots more snort to boot in addition to shaving off 3 lbs or more. Ypur TPS is basically normal. It will bounce timing at light loads and high speeds. Just unplug it if you do lots of this type of riding. ANd plug it back in when on the trail. If its left unplugged, your ignition mapping goes into a default and you will have a power loss.

[Scott_V]

(came with a 160 in it) .

Mine had a 165 in it stock

But your jetting will consume too much fuel.

30 miles yesterday and about a 1/2 tank. That is way better than my old ringdinger and good enough for me

It does feel a bit lean when I start geting around 4500, but I just drive around it, knowing I dont spend too much time up there.

Isn't it the higher you go the richer your setting gets? ?

Also, get a ZIP ty fuel screw, great for fine tuning on the trail.

GOT IT!!!!

And the stock muffler is really heavy. I use an FMF Powercore4 witht he quiet core insert and its 93 db, and will give you lots more snort to boot in addition to shaving off 3 lbs or more.

3 lbs really won't do much for me. If it was 10 or 15 yes. But $400 plus dollars for 3lbs and possibly a slight performance gain that I probably wouldn't notice? The stock one with the GYTR insert breathes well enough for now. $400 will buy the suspension work that will make me a better rider.

Ypur TPS is basically normal. It will bounce timing at light loads and high speeds.

I'm still not sold on this. Maybe I'm a consipracy theorist but there is a possiblity that these just aren't set optimally from the factory for my type of riding. I've heard of people changing these with great results. I'm imagining the timing curve they put on these things to just make them run all choked up and it's my guess that the mapping is probably not optimal and is just a make do so the pig will pass emissions.

Anyone else have a TPS story?

[trailordune]

i'm in western WA, similar conditions. after jetting i had light throttle stumble, unplugged the tps and it's gone and i don't notice any power loss off rode with it unplugged. sounds like you need a 48 pilot and smaller leak jet for oregon riding. look at Indy's jetting spec at top of page. I run a #35 leak jet + 72 starter jet, works well. this is for an 04.