2008 Yamaha WR450F Mods

[dladle75]

Hi, I have been searching around for a solid thread on doing the free mods on a 08' Yamaha WR450F, but have not found one specifically...any help? Also, what are some other mods worth paying for that will make the bike run to its full potential?

I get the bike on 3/9/09, bought a FMF Q4 Silencer exhaust to replace the stock and a dynojet kit for for the high altitude. I ride mostly in Colorado above 7000 feet. Thanks.

[honeycutt]

You can use the search feature in this section and the 07 thru 09 are all the same exact for the bold new graphics. Have fun:ride:

[Tonson]

After the Free Mods, the Best money I spent on the '08 WR450:_

Suspension:- respring to your rider weight and revalve.

Scott's Steering Damper with Sub Mount kit.

AIS Removal Kit

I'm 6'4" and 245lbs w/out gear. Ride mainly desert trails and life sapping coastal dunes. It took me a year to decide on spending this amount of money. Now I kick myself for not doing it right away from new.

The suspension work has transformed the handling of the bike and my confidence in tackling the rough stuff. It now does the work, not me. I can ride harder, faster and more aggressively and feel safer at the same time.

[dirt03]

Get the AIS removal kit. Its cheap and plenty worth it to get the full potential from the bike.

[dladle75]

Thanks dirt03, just ordered the AIS removal kit from ThumperTalk for a low price! I heard mixed reviews on doing it, but it appears it is a crowd favorite, can't beat the price either.

It seems as if all the mods tie together and have to be down at the same time...AIS removal, rejetting, throttle screw, exhaust upgrade, grey wire. Am I missing anything important?

I'll probably not even get a chance to ride the bike stock as I went to fire it up for the first time, the battery didn't have a charge & the weather went back to winter for a few days. Unable to kickstart it either. Go figure!!

[Routt North]

I have the 08" WR450 and did the AIS kit from TT. It is easy and well worth it. I also did the gray wire. The performance is great. My next step is exhaust and I think i will be done with the engine stuff.

I also agree with Tonson on the suspension. If you are not in the designated 140lb. to 180lb. class then you should at least upgrade the fork and rear springs. Factory Connection is a great resource.

Good Luck and have fun - It is an awesome bike.

[homer2000]

hi just wondering guys where i find the free mods section

[WR_Dave]

Open the WR400/425/450 forum and directly above the first thread there is a WR Performance sticky thread. Open that and near the bottom of it there is an '07 mod section. WR Dave

[CharWR450]

Thanks dirt03, just ordered the AIS removal kit from ThumperTalk for a low price! I heard mixed reviews on doing it, but it appears it is a crowd favorite, can't beat the price either.

It seems as if all the mods tie together and have to be down at the same time...AIS removal, rejetting, throttle screw, exhaust upgrade, grey wire. Am I missing anything important?

I'll probably not even get a chance to ride the bike stock as I went to fire it up for the first time, the battery didn't have a charge & the weather went back to winter for a few days. Unable to kickstart it either. Go figure!!

Do the air box mod (airbox snorkel).

[RockIslandRider]

Looks like you are on your way. I assume by now you've done the AIS removal kit, and ALL of the "free mods" posted on TT.

These are all excellent and necessary mods to "uncork" the stock bike. I have an '08 WR 450, and almost have the machine dialed in. The following worked for me - can't say it will work for you - but my bike pulls like a tractor... and flat out halls butt when i'm not in the forest. NOTE: the heavy fly wheel tames down the "yank" that a YZ produces... and helps maintain momentum in the technical stuff. Depending on your riding style and where/what you ride, you might want to consider some of the following:

yz 450 exhaust cam - somewhat expensive, but great improvement in performance. Definately worth the bucks. The '07 and '08 cams have sligthly less overlap than earlier models. I used an '07 YZ exhaust cam.

You will need to re-jet the carb. You are at 7,000 ft., so I don't know how to advise you on jetting, except you want to mirror the jetting for a YZ 450. You will need to by-pass the Air Cut Valve. Look for the Air Cut Valve post on the TT site. Use a #100 pilot air jet - #70 is stock for the WR. Buy a stock YZ needle (NFLR) unless you want to spend the $ for the JD kit. Buy the JD kit for the YZ, not the WR. At 7,000 ft. you might need a leaner needle. On second thought... but the JD kit.

YZ exhaust header. Much larger diameter, more free flowing. The '07 YZ 450F Exhaust header will bolt right on. Don't try to order an OEM graphite gasket, because they don't make one for this mod. Go to NAPA, and but a sheet of Fel-Pro 2499 Pro-Ramic high temp gasket material. It comes in a 12" x 28-1/2" by 1/16" thick sheet. Motor heads use this for home made exh. gaskets. You may have to special order. Cut a piece about 1-1/2" wide and wrap it around the YZ header. Make sure the ends butt up perfectly. Slide the stock exhaust pipe over and clamp it down. It fills the gap perfectly. This will help mid to top end. I didn't notice much loss on the bottom, but i did this mod at the same time i dropped in the yz exh cam. I don't have a big budget, but you can use the same principle with an '07 YZ mega bomb or power bomb header.

Buy a couple of new rear tires. You'll need them.

Power Now is a great mod if you do allot of tight technical stuff... and have an extra 100 bucks.

I hope you have your MSO. If you do, make your bike street legal w/ a Baja kit. Spend the money for a Trail Tech Vapor. If for any other reason, it has a coolant temp sensor and a tach.

Aloha and Good Luck

[dladle75]

So far I got rid of the AIS, shortened the throttle stop, removed the air box, threw on a FMF Q4 exhaust. The bike definitely opened up after the first round of mods.

The battery was 2 years old & was junk. A new one fired the bike up.

Did an oil change at 40 miles & the bike felt much smoother through the gears.

The stock tires they give ya, have worn rather fast after 50 miles. Think I'll give the Maxxis a try.

I plan on rejetting for high altitude & throwing in a scary fast power now.

Maybe cut the gray wire when I put on a bigger 3.6 gal tank.

You can have never have enough power. Great bike so far!

[William1]

Do not waste your money on the powernow. Properly jet and adjust your carb instead unless you do not mind slowing the bike down. Buy a James Dean jet kit. Do the oring mod or install a Merge Racing stiffer AP spring. Set your AP timing. Maybe splurge on an ALJ (adjustable leak jet) - worth it on an alloy framed bike due to carb R&R being such a PITA. Plan this all out and do it at all at the same time, slowlt and methodically.

By doing the muffler and opening the airbox, you may be running a bit on the lean side, so get the jetting done soon.

Do the grey wire asap.

The AIS does nothing for power. All it does is lighten the bike a little, make it easier to work on with less junk in the way and less BS to possibly fail. However, it is very important to remove or disable if you use a wideband A/F to tune your bike.

[Mtn-Track]

YOU DON'T NEED TO SPEND A TON OF $$$$ ON CARB KITS!

This is mine. Runs like a ROCKET! Yeah, I LIVE AND RIDE IN YOUR STATE!

Year: 2008

Model (400 - 426 - 450): 450

Cam Timing (WR/YZ): WR

Main jet: 152 (yes, a 152!)

Pilot Jet: STOCK

PAJ: STOCK

Leak Jet: STOCK

Starter Jet: STOCK

Fuel screw (turns out): 2

Needle Model/Clip position: GYTR-AIS REM. KIT "MYSTERY NEEDLE", 2ND FROM THE TOP.

Grey Wire Mod (Y/N): Y

TPS Connected (Y/N): Y

Airbox Snorkel/Lid (on or off): OFF

AIS Removed (Y/N): Y

Airfilter Brand: STOCK

Exhaust Brand: FMF POWERCORE 4

Average Altitude: 5000-14,000ft

Average Temperature: 50-80F

Average Humidity: Pretty darn DRY!

Degree of Satisfaction (0-10): 9.5

Additional Mods/Comments: This bike runs STRONG! NO STUTTER or any overheating from 5000-11,000ft, and starts instantly. Above 11,000ft some of the stutter starts to come back, but it's minimal, and it still starts right up. No bog or hesitation anywhere in my altitude range!

[dladle75]

Not to change the subject, but what is everyone's thought on the Scary Fast Power Now product for the carb?

[Woodrider37]

2008 WR450f owner, I love it. mine is.

AIS Removed Kits.

Fuel screw turns out 2.

Grey Wire Mod .

Airbox Snorkel/Lid - ON.

Baffle removed

Happy Trail