426 Big Bore

Does anyone know a place that sell a Big Bore for an 01 426? I know Luke's racing has a 444 but does anyone have anything bigger? Or can you swamp a 426 motor with a 450?

444 is exactly 5 cc short of the 449 displacement of the 450. I doubt you'll miss the extra 5.

444 is exactly 5 cc short of the 449 displacement of the 450. I doubt you'll miss the extra 5.

Gray - Is there is difference in stroke between the 400/426 and the 450? I ask 'cause my 400 (now 444) feels downright anemic compared to my 450 in the low end torque department.

Yes, the 450 has a 63.4 mm stroke vs. a 60.1 for the 426

Yes, the 450 has a 63.4 mm stroke vs. a 60.1 for the 426

How does that translate into differences in power delivery given that the displacements are the same (almost)? Low end torque?

444 is exactly 5 cc short of the 449 displacement of the 450. I doubt you'll miss the extra 5.

agree but I would like to get up to the 480CC I was thinking if you can swap a 426/450 then a 480 would probably work

agree but I would like to get up to the 480CC I was thinking if you can swap a 426/450 then a 480 would probably work
I'm not 100% certain that it's a bolt-in, but it should be doable using an '03-'05 YZ450 or an '03-'06 WR.

But, with the prices of early YZ450's being what they currently are, why not start there and get a suspension upgrade along with it?

How does that translate into differences in power delivery given that the displacements are the same (almost)? Low end torque?

An engine with a longer stroke in any given displacement will produce its power at a lower RPM than one with a relatively shorter stroke. It's a function of piston speed which is higher with a longer stroke.

So I take it the 03-05 450 engine/frame is similar to the 426?

I can just take off the cyclinder of a 426 and replace it with a 450/480? that would be sweet!!

No, and it wouldn't change anything if it did fit. The bore of the 426 is the same as the 450 at 95 mm. The stroke is determined by the crank. (and no, that won't fit, either)

No, and it wouldn't change anything if it did fit. The bore of the 426 is the same as the 450 at 95 mm. The stroke is determined by the crank. (and no, that won't fit, either)

hey gray

i am confused. would i be able to put on a 480 big bore kit from a 03-04 yz450f onto a 426?

hey gray

i am confused. would i be able to put on a 480 big bore kit from a 03-04 yz450f onto a 426?

..No.

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