Will an '09 WR450 crank fit into an '06 YFZ450?

[like it like it]

I have this 2006 YFZ450 stuck in the garage for a long time but it's well-maintained, we just don't bring it out. We do regular maintenance and all that. It was from my late father, so it was kinda hard to touch it after he passed. Now we're deciding to move on and we've got access to a brand new OEM 2009 WR450 crank. I know the older WR cranks are a match, but I'm not sure about the '09. Does anyone know if it'll fit perfectly or if there are clearance or spline issues? I want this to be perfect to honor him.

 

[JemP1990]

I havent tried the 09 crank myself, but I’ve heard the older WR cranks usually fit without issues. The 09 might have some slight differences though, so double check the spline count and clearance just to be safe

 

[GearHeadache]

I have this 2006 YFZ450 stuck in the garage for a long time but it's well-maintained, we just don't bring it out. We do regular maintenance and all that. It was from my late father, so it was kinda hard to touch it after he passed. Now we're deciding to move on and we've got access to a brand new OEM 2009 WR450 crank. I know the older WR cranks are a match, but I'm not sure about the '09. Does anyone know if it'll fit perfectly or if there are clearance or spline issues? I want this to be perfect to honor him.

Hey, man, that's an awesome tribute to your dad. Unfortunately, an '09 WR450F crank probably won't be a direct, perfect fit for your '06 YFZ450.
The biggest hang up is often the wrist pin size (YFZ usually 20mm, many WRs are 18mm for certain years).
Even if it physically bolts in, there could be clearance issues with the piston or balance differences.

what you need to do is to compare OEM part numbers for both cranks. If different, it's not a perfect match.
also call an expert engine builder who does Yamaha ATV/dirt bike motors. They'll tell you straight up what's involved (like needing a different piston) or if it's not worth it

 

[collincolt45]

Its close but not a perfect fit. You can MIGHT make it happen with some modification, but it's not guaranteed. For a perfect, hassle-free swap, it's best to stick with a crank specifically made for the YFZ or double-check compatibility with a trusted mechanic.

 

[Toph]

Swapping in that 2009 WR450 crank might work mechanically, but if it's not a direct match, forcing it in risks damaging a motor that holds sentimental value, you might be better off finding the exact YFZ450 crank even if it takes longer, just to keep it pure and true to your dad's original build

 

[Y0nko]

Better to compare the crankshaft part numbers and doublecheck bearing and spline compatibility before installing. It might still work with some machining or extra parts, but for a tribute build, OEM match would be safest