07 yz450f crank bearings shot

[Handy Andy]

Alright, thanks. So it's pretty safe to assume that it's just the bearing in need of replacement?

[grayracer513]

Yes. I also disagree with your original premise that the end play was making any noise at all. If the mains are at fault, it's the radial play, not the end play.

[Handy Andy]

Yes I agree that in theory there will not be any axial movement of the crank while the engine is running regardless of if there is excessive end play. However in this case if you feel the minimal amount of force required to move the crank side to side it is understandable that due to tolerances, vibration, etc. that during operation it is possible that there will be axial movement, and if you pull the crank back and forth it makes a distinct clunk very representative of the noise it makes while running.

[Handy Andy]

I tore it apart yesterday and the bearings are indeed bad. It also has a hot rods crank in it...I assume the bearings were hot rods (read: chinese) too.

[grayracer513]

I tore it apart yesterday and the bearings are indeed bad. It also has a hot rods crank in it...I assume the bearings were hot rods (read: chinese) too.

Hot Rods cranks are not Chinese. They are sourced from Taiwan.

[letitride]

What crank and gasket set are you using?

I'm using all OEM, the wiesco kit was tempting for the price but I figured you can't go wrong with OEM. Through hondaeasttolledo.com it ends up being around $125 more then the wiesco kit.

[letitride]

I put my bottom end together last night, The new crank sits tight inside the bearings the only side to side play I get is the amount thats in the bearing, the old crank would slide back and fourth in side the bearing. But I have the same radial play that I had, actually feels like a little more probably will feel the same once theres some thick oil coating the bearings. Before I put the bearings in I compared them to the old ones side by side and I wouldn't have been able to tell the differnce between the two. I'm thinking there was nothing wrong with my crank and main bearings and even that transmision bearing that felt bad freed up after heating the case and trying to work my bearing puller in.? O well I pretty much have a brand new motor now:thumbsup:

[crf450319]

I've got my bike apart right now, replacing the top end and found that a new cylinder would be a good idea.

I have 0.012" axial play on the end of my crank (dial gauge), I was looking for this thread hoping that someone else had measured with a dial gauge indicator and had posted what they got... found only 1 result on the first page of this thread. From what I've read, it sounds like the movement I've got is somewhat normal.