07 WR450f speed issue

Merlin450 - to answer you question I don't necessarily need to do 100mph but I just noticed on the trails I needed a little more power. I ride in Upper Michigan near Houghton (parents live up here so I bought a bike to keep at their place so I can have some fun on vacations) Upper Michigan is a wonderland for ORV since they ripped out hundreds of miles of railroad tracks so the trails are wide and all the trails go through every town up here so getting refueled on gas or food/drink is easy, going very long distances is a snap. If anyone in this forumn wants some of the best trail riding.. this is the place. Plus it has some of the best snowmobiling, which is my second love. I went riding today with my friends and even though I didnt have time to do any mods I had no problem keeping up with them.. anyway I really appreciate everyones comments and I will start the mods to see what I get out of it.

bodi

We need to go back to the original ?... the bike is an 07, therefore a 13/50 stock gearing. the 06 and previous have 14/50 stock. change the front to a 14, lengthens the gears a little, making 1st now manageable. top speed will change to 80 mph. for all you guys doing 90+, please recalculate your tire diameter or make sure you are in MPH not KPH in the speedo, you are not doing 90+ !!!!

We need to go back to the original ?... the bike is an 07, therefore a 13/50 stock gearing. the 06 and previous have 14/50 stock. change the front to a 14, lengthens the gears a little, making 1st now manageable. top speed will change to 80 mph. for all you guys doing 90+, please recalculate your tire diameter or make sure you are in MPH not KPH in the speedo, you are not doing 90+ !!!!
I've done all the base mods, Powerbomb FMF Ti pipe, 15-45 gearing, Vegas2 Reno last year 102 mph GPS. 15-48 gearing, yesterdays local desert race 83 mph. Jeff S
Merlin450 - to answer you question I don't necessarily need to do 100mph but I just noticed on the trails I needed a little more power. I ride in Upper Michigan near Houghton (parents live up here so I bought a bike to keep at their place so I can have some fun on vacations) Upper Michigan is a wonderland for ORV since they ripped out hundreds of miles of railroad tracks so the trails are wide and all the trails go through every town up here so getting refueled on gas or food/drink is easy, going very long distances is a snap. If anyone in this forumn wants some of the best trail riding.. this is the place. Plus it has some of the best snowmobiling, which is my second love. I went riding today with my friends and even though I didnt have time to do any mods I had no problem keeping up with them.. anyway I really appreciate everyones comments and I will start the mods to see what I get out of it.

bodi

Bodi do all of the mods that you can. Bike was designed to do roughly 100 WOT but had to be limited due to emissions for sale in the US. You might say that the Factory had to do these mods and we are UN-doing them. I ride an 05 and street it regularly. No matter where I am or what gear I am in, it is nice to go wide open sometimes like when you need that 'bump' to pick the wheel up over a root or a hole or pass that grocery getter. On the freeway, if you dare, the turbulence can get rowdy so you wanna be able to maneuver. 70 ain't gonna get it when everyone else is runnin 80. I have ridden next to a caddilac with digital display reading 95 and could just barely pull away WOT. So I actually want more:eek: but can work with what I have. Have always wondered about the guys runnin YZ cams in theirs. Wonder what they can do..:applause:

You wont see 90 with stock gearing and all the free mods. like Jeff said,we had some really long really fast sections in our last race. I have all the free mods, stock gearing, correct jetting for the altitude and temp, and a 110/100 on the rear. Wide open in fifth for about 5 minutes (I'm not kidding) around 82-84 mph. It gets to the mid 70s pretty quick but after that you get about 1mph per every 5 seconds. maybe at sea level and going down hill you could hit 90 but seriously I doubt it.

I dont know how acurate the speedos are either. The fact that was able to hit the same speed as Jeff (48 vs 50 tooth) makes me question it. He does weigh a little more then me and runs a bigger/heaver tire but still...

The throttle stop has to be the biggest issue here - the bike is HALF THROTTLE stock! It barely turns! If you can't access your top RPMs, you can reach top speed. The YZ stop's gotta be another 20mph...

I have only had my bike for a few months so all of my riding has been in the mountains so I haven't pushed the limit yet. A friend has an 06 WR450 and we were out in Johnson Valley this past winter and he had it up to 83 mph on Soggy drylake.

I don't think you get the big increase in total mph with the throttle stop removed. You just get there a whole lot quicker. He rode his bike once out there and he couldn't make it half way up the sand hill. Once the stop was replaced, no problem (except rider skill).

From what I have read, the grey wire removal goes along with the AIS removal. I never rode my bike in stock form. I did all of the mods before it hit any dirt so I can't speak to the difference.:applause:

I too did the mods(throtlle stop, airbox, and restrictor- left the rev limiter) before it hit dirt and I top out at 85 all tucked in. Put your body in the wind and it drops to 81.

I too did the mods(throtlle stop, airbox, and restrictor- left the rev limiter) before it hit dirt and I top out at 85 all tucked in. Put your body in the wind and it drops to 81.

Pavement kicks it up a notch I reckon...Caddilac speedo said so..running a 14-45 at the time which probably helped.

Pavement kicks it up a notch I reckon...Caddilac speedo said so..running a 14-45 at the time which probably helped.

I'm sure my body weight pulls it down also since I am heavier then most.

As far as the throttle stop goes, I just completely took that screw out, No problems since. Also the grey wire, and the baffle. After that Ive gotton it up to right around 85-86. MILES PER HOUR, not KPH.

I don't know what you mean that you have to purchase something for all the mods, cut the stock throttle limiter screw 100_1003-1.jpg ( free) , remove grey wire (free), remove rear pea shooter baffle ( free), remove airbox snorkle ( free) flip ACV diaphram (free). If you think the bike is good now wait till you do these mods and then let us know what you think. :applause: WR Dave.

Why do you say "Too short" in the picture above? I completely removed my screw and it seems to work fine. Am I missing something?

With a completely removed stop screw you run the risk of pulling the throttle plate out too far and having it get stuck above the slide track. When that happens you will have a bike that is wide open all the time and you won't find that out untill you roll off the throttle and it doesn't roll off. Too much of a risk in my opinion. :applause: If it was OK to do that then Keihin wouldn't even install them on pure motocross bikes since they don't have to meet any emmisions. Note that the pure race bikes don't have the ACV valve that the off-road bikes do. WR Dave

Why do you say "Too short" in the picture above? I completely removed my screw and it seems to work fine. Am I missing something?

whoa yeah you're not supposed to do that. It can also cause trouble with your TPS, if I understand correctly.

But hey, it's your bike.

The first ride on my 06 was disappointing only topping out at about 70mph, I did all the free mods (throttle stop, grey wire disconnect, airbox snorkle, exhaust core) but didn't remove the AIS. It now does 96mph. I'm not sure how much more i can get with the AIS removed, but it does better than 70mph now. All for free........!!!CORRECTION!!! i had to check my top speed it only does 90, maybe the 10 degrees here in MI slowed me down just now..BBBBRRRRRRRRRRRRRRRRRRR

The first ride on my 06 was disappointing only topping out at about 70mph, I did all the free mods (throttle stop, grey wire disconnect, airbox snorkle, exhaust core) but didn't remove the AIS. It now does 96mph. I'm not sure how much more i can get with the AIS removed, but it does better than 70mph now. All for free.

Won't get much more..maybe 1mph if your lucky

I'm sure your bike with just the free mods will do 96....

The first ride on my 06 was disappointing only topping out at about 70mph, I did all the free mods (throttle stop, grey wire disconnect, airbox snorkle, exhaust core) but didn't remove the AIS. It now does 96mph. I'm not sure how much more i can get with the AIS removed, but it does better than 70mph now. All for free.

Nice Haze:thumbsup:

I'm sure your bike with just the free mods will do 96....

Ride it like you stoled it, I have to trust my speedo. I would not recommend running wide open for an extended time, but it sure shuts up the "green, yellow, orange and red bikes" that i ride with. GO YAMI.

A buddy of mine on a 04 Wr450 and myself on my 06 had a side-by-side- comparo (to avoid the word drag race) on beautiful stretch of straight fire road (both are DS'd), and while I was WOT, he just twisted the throttle and pulled away! And he's got another 20lbs on me! The only difference is that he's got a FMF Q4 pipe and I'm running the stocker with peashooter removed. Do you think the pipe could make that much difference? Personally, I think my throttle stop screw is a little longer. (Might have to compare our screw lengths...)

I topped out at 134km/h (84mph).

Thoughts?

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