100 hrs on 2014 yz450f, shim valves or replace them?

Yes...

&%$#@!... That delays me to getting it back together till late next week

&%$#@!... That delays me to getting it back together till late next week

Take the cylinder off carefully, you may be able to reuse the gasket. Always better to replace but sometimes they come off with no damage, and it can save your weekend...

Take the cylinder off carefully, you may be able to reuse the gasket. Always better to replace but sometimes they come off with no damage, and it can save your weekend...

I figured if I'm going to pull the cylinder and everything to do the rings I'm just going to do the the top end while I'm at it. I order a new gasket and new oem top end kit. So I'm hung up anyways :(

The base gasket is a steel shim type, and cannot be reused.

I've got a 14 450 it just started getting hard to start checked the clearance and the was no gap here's a valve out of it its done about 120hrs now I

I'm impressed that it ran at all with no gap. Have you done valve checks/adjustments before? I don't see a picture either.

The smallest gauge I had was .03 and that wouldn't go in tbh it ran alright once it was going. I did a full build on it about 25hrs ago and they was OK then

They must of just decided they've had enough lol

IMG-20160506-WA0005.jpeg

Edited by Aaron_Baker

Fortunately OEM valves for this bike are pretty damn cheap.

 

Edit:  Head assembly is only ~$335 too.

Edited by GHILL28

Not here in the UK they was about £50 each 

In that case it might not be a bad idea to get someone in the US to send you a new complete head. Not that much more than new valves.

Does this cylinder need to be honed? You can still see the lines going horizontally and doesn't seem glazed but I'm not sure. What do you think ImageUploadedByThumper Talk1463015241.157308.jpg

Does this cylinder need to be honed? You can still see the lines going horizontally and doesn't seem glazed but I'm not sure. What do you think ImageUploadedByThumper Talk1463015241.157308.jpg

That side looks great to me.

That side looks great to me.

So if the whole thing looks like this you wouldn't worry about getting it honed?

I'm a huge proponent of using ball hones on Nikasil four-strokes, but that one simply doesn't merit doing it.  Clean it up with a Scotch-Brite and run it.

So if the whole thing looks like this you wouldn't worry about getting it honed?

I would put it back in as is, no honing.

Well guys I got it all finished and I have the bike broke in!! I must say it went pretty smooth and thanks to all you guys for helping out answering my questions! I really appreciate it. I pretty much followed the same break in period as the Manual recommends (I did the same when it was new) and everything seems to work flawlessly with no leaked or anything.

I think a little bit of coolant got in the bottom end when I was taking it apart. So I refilled with new oil and And after the initial start up, of Idling for a few minutes, I drained the oil again and it was a little cloudy. So I refilled it again and did my break in. Going to dump the oil again tomorrow and refill it again.

Fortunately OEM valves for this bike are pretty damn cheap.

Edit: Head assembly is only ~$335 too.

What website to order from?

BikeBandit, Chapparal, RockyMountainATV, etc etc

If anyone's interested there's a 16 yz450f head for sale in Thumper talk classifieds. I believe the guys asking 350.00...Seems like a smoking deal for a head with 5 hours on it.

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