2007 WR450 Performance Mods

Forgive my ignorance. What is the large piece on the top left with the tubing. Is that the AIS? I didn't see in your pictures where you removed that.

Thanks so much for posting the pix. I should have mine in a few weeks. :worthy:

To remove the small baffle from the muffler remove 6 allen screws and remove the end cap. Next drill out the two rivets holding the baffle in place (arrow). Use neddle nose pliers to pull it out.

muffler.jpg

Please let me know if I'm wrong, but can't you remove the hole insert by unscrewing the four allen head bolts? Thats what I did on my '06 and replaced the end cap. I didn't drill any rivets.

Forgive my ignorance. What is the large piece on the top left with the tubing. Is that the AIS? I didn't see in your pictures where you removed that.

Yes that is the AIS.

Please let me know if I'm wrong, but can't you remove the hole insert by unscrewing the four allen head bolts? Thats what I did on my '06 and replaced the end cap. I didn't drill any rivets.

I am told that doing that doesn't allow enough back pressure and makes it loud. The noise makes you think you are all fast and powerful when actually you are not.

Well, I definatley notice the difference. Anyonee else familiar with this topic?

I am told that doing that doesn't allow enough back pressure and makes it loud. The noise makes you think you are all fast and powerful when actually you are not.

Back pressure my ass :worthy:

You were misinformed, the only purpose that tiny insert serves is to make the bike rev slow and choke the engine down! Even the PMB insert allows for decent gains while still being whisper quiet

Listen to the riders on this board, the stock WR pipe holds this bike back big time!!

Sounds like if you remove the whole assembly, then you can at least put it back on if you don't notice a difference, yes?

I don't guess buying a rivet gun is that big of a deal though, but do you destroy the small baffle when you remove it? Could it be put back in if you really felt the need? I can't imagine why you would though.

Sounds like if you remove the whole assembly, then you can at least put it back on if you don't notice a difference, yes?

I don't guess buying a rivet gun is that big of a deal though, but do you destroy the small baffle when you remove it? Could it be put back in if you really felt the need? I can't imagine why you would though.

Yeah the stinger is removeable or replacable with the bigger one seen here

http://shop.thumpertalk.com/product_p/exh_pmb_wrinsert.htm

Once you drill out the little baffle, its a done deal unless you weld it back in...but why would you want to do that?

msgbean what did you use to plug off your ais?

Has anybody seen or heard of after market mufflers for the 07 WR450F yet e.g Pro Circuit , FMF etc

My first thought would be to check their specific websites :worthy:...SC

My first thought would be to check their specific websites :D...SC

How helpful sometimes there not on there but are available:rolleyes:

Oh and i did check those 2 websites too. It doesnt have to be those brands. :worthy:

msgbean what did you use to plug off your ais?

I used the Yamaha kit but it was for an 06 and the exhaust plug doesn't work so I found me piece of metal about 1/16" thick, drilled two holes in it for the screws and used the original gasket.

How did you plug the hole in the head? In your picture you show the pipe that goes into the head. Did you plug it with something home made? I had a difficult time getting the heat shielding piece and metal cap/clamp onto that piece of tubing. I had to cut of the end of it and use high temp silicone to attach that piece. The kit I used was for an 06 as well. I called GYT-R service line and talked to the tech who was making the kit for the 2007 which will be out in a few weeks. He said that the cap and shielding I had would not fit on the tube that goes into the head. That is why I cut the flange on the end and siliconed the cap on.

why would you drill out the baffle rivets when you can remove the 4 allen screws and take it out? That is what I did and it is neither too loud, nor does it inhibit the motor with a lack of back pressure. The pipe diameter, lenght and bend creates enough backpressure to make the bike run perfect. That is how they choose the pipe size, length, and bend to begin with.

Oh and i did check those 2 websites too. It doesnt have to be those brands. :worthy:

How about this then...Figure out what brands you might want and then call the company. The '07 is brand new, so common sense tells me that the aftermarket companies may not have anything available just yet...SC

How did you plug the hole in the head? In your picture you show the pipe that goes into the head. Did you plug it with something home made? I had a difficult time getting the heat shielding piece and metal cap/clamp onto that piece of tubing. I had to cut of the end of it and use high temp silicone to attach that piece. The kit I used was for an 06 as well. I called GYT-R service line and talked to the tech who was making the kit for the 2007 which will be out in a few weeks. He said that the cap and shielding I had would not fit on the tube that goes into the head. That is why I cut the flange on the end and siliconed the cap on.

The nice thing about the 07 is that the pipe is now bolted to the head. I found a piece of metal about 1/16" thick and I traced the end of the pipe onto it. Used a hack saw to cut it to shape, then drilled two holes into it. You can use the metal gasket and screws off of the pipe to hold it in place. I forgot to take a picture of it before I installed it and I'm not taking it off again so here is the best I can do photo wise.

plug.jpg

I used the Yamaha kit but it was for an 06 and the exhaust plug doesn't work so I found me piece of metal about 1/16" thick, drilled two holes in it for the screws and used the original gasket.

Thank you

My first ride on my 07 wr450 was like riding thoroughbred with the two hind legs tied together. It feels light and nimble just like an YZ but just as the power hits it stops pulling. After riding for about 3 hours I thought to myself “Self, you need to uncork it to let the beast out.”:D

Mod 1: Pulling the snorkel from the top of the air box leaves plenty of CFM’s for the carburetor.

Mod 2: The “Gray wire” mod is now the “Blue/White” (Sky blue for everything other than USA) :cry: wire mod. I looked at the wire schematic and found the best place to cut (or pill) the wire is at the CDI unit. The CDI unit has three connectors; you need the connector with three wires. Look for the wire that changes from blue/white to sky blue going to the CDI. Pull out the blue/white wire out of the connector and fold it back into the conduit then electrical tape or silicone it in order to water proof it. This is a good idea if you won’t to change it back to factory or servicing. The second reason is that it will not interfere with the starter circuit at all.

Correction: The "Gray" wire mod is for YZ mapping and the "Sky Blue" wire is for better starting in neutral. Sorry guys!

http://www.thumperfaq.com/gray_wire.htm

http://www.thumperfaq.com/blue_wire.htm

Mod 3: AIS removal is a walk in the park. Items to acquire are an assortment of vacuum plugs from the auto store and a piece of 1/8” x 3/4” steel or aluminum stock for the block off plate. Start by removing the seat and tank for access. You will have to loosen up the left coolant hose right next to where the air injection pipe meets the head in order to access the bolts. Once the AIS system is off use the flange on the injection pipe as a template to trace a pattern onto the 1/8” x 3/4" x 2” stock. Drill two 17/64” holes 28mm apart and grind away the rest to shape. Use the existing bolts and gasket to install it. I pulled up the coolant hose and used a ball point allen wrench to break loose and tighten the left bolt. Cap off the Vacuum port and air box port with the vacuum plugs accompanied with the factory clamps for security. This is imperative if you wish reinstall it for a street legal cert at a later date for state inspection. (Save your old parts!)

Mod 4: Let me just say two words, “Throttle Stop” &%$#@!! After removing the sub frame and shock to access the carb, I twisted the throttle to see how much it opened and much to my surprise, HALF WAY! I am not kidding and don’t call me Surly! :prof: I could not have pulled out that screw and shorten it fast enough. 12mm off stock screw, 18.2mm from shoulder to tip. While the rear shock is off, pull apart the swing arm and linkage and lube it with a high quality grease and loctite and re-torque all the nuts and bolts.

Just waiting for my JD jetting kit, mixture screw and PMB insert. Stiffen up the preload on the rear shock for my 210 lbs. dead weight and I’ll need clearance from Houston in order to launch! :bonk:

I will give you some pics once I learn how to attach them. :worthy:

Guys you are killing me.

Do NOT post anymore write ups about the 2007 WR450 till I get mine. LOL

My dealer keeps saying any day now. I told him I could have drove to California to pick it up.

Keep up the good reviews.

I want to ride................................

65 in Texas today..........................

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