Welp, QUAD CROSS YFZ450 has already done this. Here are the part numbers. All you do is connect the pull cable through the original hole on the carb and then drill out the other bit where the push cable goes through. I do not know how he bi-passed the electrical thingie on his. Also the carb on these is the same as the WR carb but they have a 100 pilot air jet versus the 70 pilot air jet on the WR.
yamaha microfiche page www.yamaha-motor.com click on part-service, then scroll down menu click on parts catalog, then WR 450F
I'm not sure where else to look up prices for those part numbers so cheaper places would be great.
Edgerat: what is that last COLLAR for? I didn't see that part number listed on the throttle assembly, or the carburetor side?
Motion pro should have one out soon, I heard that they already do, and it's about $66.00, but it may be on back order.
Hope this helps, I'm probably going to go this route, just because I don't like Motion Pro's products, and have more faith in OEM equipment.
I am not sure if the collar is the little thing that sits under the brake lever perch or if it is part of the throttle. That is just all the parts from that side of the bars. Bob at Magnolia yamaha can get you a better price on all those parts. he quoted me a price under 100 dollars.
On the electrical, I connected both of the wires off the thumb throttle to make it work. Because the bike would not rev out until I connected them. You don't need the collar, I didn't use it on mine. I've had it for three weeks and haven't had a problem with it. :woo
what did you do on the Carb side? did you have to drill it out? how did it connect in the inside? any other special parts, or was all able to snap together? I'm going to be buying this asap, and would love to know everything before I take on this task. Pictures would suuuuuuuure be nice... :lol :lol
Well, I was looking through the part numbers for the other 4-stroke yz/wr bikes, and the throttles are universal(same part numbers). The only thing that is different are throttle cables themselves. So I just bought a 2001 yz426F twist throttle off of ebay for $40.00. Mine is coming with the throttle cables too, so I will be able to see if those cablles will work. This may be the cheapest route to go for the twist throttle.
There is also a guy selling billet throttle tubes for 30.00 bucks to replace the cheap plastic one.....
Well I just finished mine today. The 2001 yz 426F throttle and cables fit perfectly, so I would venture to say that they are all universal. On the Carburetor I'm not sure how QUAD CROSS got away with only drilling a whole, cause the throttle cables come complete, with the nut attached, so I also cut a slot in the side of the carburetor to fish it through. It looks just like the bottom throttle hole now. The fit and finish is real nice, and there is no lag in the cables, or throttle housing. If you want a twist throttle, this is a good way to go. I bought my twist throttle complete off of ebay for 40.00, which is cheaper than the motion pro set-up. But beware you'll need to perform some surgery on your carb to make it work. I will post some picture of what I did to make it work later today.