yz400f to a wr450

[Bills racing]

I live in Anderson Ca. Im pretty sure that I have the only 426f/400ex hybrid in the county. So Im asking for help. How hard would it be to put the wr450f motor in my frame. They look like the exact same motor. Please help.

[CrackerboyLV]

I'll let you know. I'm putting a 2004 WR450 in place of my 2002 426 this week. I can't wait to have e-start...

[dehner47]

dude, there are hundereds if not thousands of 400ex hybrids with 426 motors stuffed in them. search this forum. you'll see plenty of them.

[CrackerboyLV]

I believe he already has a yz426 motor, he is looking to put a wr450 motor which is slightly different.

Here is what I have found out so far....

The 2004 wr has an 18mm pivot bolt hole. My yz had a 17mm. The earlier bushings are a smaller OD as well, but my case was machined for both. Press out the 18mm and press in the 17mm.

The lower engine mount hits the engine sump and does not allow the engine to drop into place without some grinding. It will most likely need to be removed and replaced with a new mount.

The rest of the mounts appear to be close. I won't know for sure until the lower mount is removed.

the oil lines are different, but the procedure should be the same as modifying the 426 lines.

The clutch cable feeds from the side and may be too short.

The coil on the wr is part of the spark plug wire and gets very close to the bottom of the gas tank.

[Bills racing]

Let me know how it goes. I can get a complete dirt bike for 1700 bucks. Im not racing anymore so I would like to make a sand bike out of this thing. But if its a pain it can just sit in my garage.