Laegars 426 Chassis, making a YFZ450 motor fit...

[Paul400ex2002]

Ok guys I recently bought two complete laegars protrax chassis that are set up for yz426f motors. I'm wanting to put my yfz450 motor into one of them, and probably sell the other one. I have a set of junk cases i used tonight too kind of see what the situation looked like, and it seems like in order to make everything work the motor will have to sit too far to the right... Mainly because the sprocket won't line up if the motor was mounted where the 426 is.

Anybody have any ideas/insight on making the motor fit

[matt250r21]

I have a Laeger YZ 426 too, and tried to fit a 04 YFZ 450 quad motor in. I remember the lower motor mount was off and the chain wasn't lineing up. I didn't want to hack up the frame so I stopped there. I would just put the YZ 426 or YZ 450 motor in the Laeger if I were you. They are better then the quad motor anyways.

[Paul400ex2002]

that's my dilemma sorta. I have the 426 motor, but it's stock. I just spent 2500 bucks on my yfz motor because it dropped a valve, and i have a brand new cylinder, head, crank, etc. Do you know if it's possible to use the yfz head and cylinder on the yz426?? I know the cranks are different, but I think i may be able to use my falicon rod on the 426 crank, then get the 426 crank balanced.

[matt250r21]

Sorry, I don't know if any of the parts will interchange.

[2muchquad]

Sorry the heads are different.:(

[800screws]

i'm pretty sure the yz450 engine also will not line up with the 426 mounts...the lower motor mount is like 1/8 of an inch off.

[honda380]

how much you selling one of those frames for?

[Paul400ex2002]

i'm not really sure yet, let me get back to you on that. Shoot me an email so we have a better way to communicate. Paul416ex@yahoo.com

[jrspawn]

Hey, the YFZ450 is more of a pain to "correctly" fit into the 426 style chasis, and a little waste of time really. You are much better off with a YZ450f engine. I prefer the 03's. It will fit with little modification. I have done this a few times and works perfect. The lower motor mount(very bottom of engine) will be off by about 1/8", do correct this you can just slot your bottom mount(dont be affraid, keep a steady hand:D ) Then you will need to slot the headstay mounting hole where it bolts to the head, to do so once again get the good ol trusty die grinder and slot the opening, you will need to slot it all the way down, as the mounting point of the headstay is lower than the 426, finally you will need to make a new oil drain hole for the 450 as the 426 hole is way off. This is what lost creek and about every other company did when they moved from the 426's to the 450's with the hybrids. Walsh only made a handfull of true YZ450 frames. The key thing that tells the diff. between the yz and yz450f chasis was the drain hole location and size.

Justin

[Paul400ex2002]

how is the reliability of the yz 400/426 bottom end? The yfz head will work I believe, i have a junk one off my old motor and it fits perfect on the yz cylinder, i don't have a yfz cylinder here to see how it fits, but I'm pretty sure I can use it as well. I'm going to have the crank built, hopefully using my falicon rod off my yfz crank, and have it balanced. I'll be pulling the yz motor apart and checking clearances to see if i can get enough stroke out of it to bring it to yfz specs.

Anyone have rod length specs of the yz 400/426? I've got the stroke specs but I need to know what rod length they use. I want to use a yfz rod, hopefully mine, because of the bigger wrist pin, and i already have it so it'd be good to use.

This motor will be completely crazy if i can make everything work. My yfz motor flat out HAULS and the 426 cases are much stronger than the yfz, and i'm sure it'll make the same if not more power.

I heard that the 426 bottom end with the stock 450 top end will cause problums over time for what ever reason it was.

My 426 motor siezed after 1 oil change.