Is my cylinder junk?

2 replies to this topic

Posted May 14, 2013 - 02:47 PM


Hello, I have a 05 yz450f it started smoking real bad.
i took it apart to do the top end and i assume this wear at the top is through the plating and the cylinder is bad, but im sure.

Also because my bike was smoking real bad what can i look for in the head to make sure its not coming in through there and not the rings. I would hate to just do a new cylinder piston and rings and it continue to smoke because i over looked the head?

Attached Thumbnails

  • 4 (1)_01.JPG
  • 4 (2)_01.JPG
  • 4 (3)_01.JPG
  • 4_01.JPG

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • grayracer513

Posted May 14, 2013 - 02:53 PM


The only way the head could be involved is via the valve guide seals or the head gasket, unless there's a crack someplace, which isn't very likely.

The cylinder appears to have significant wear, but without precisely measuring it, you can't really know. The pictures don't definitely show the plating being worn through, but if it is, you will normally see it as a distinctly grayer look tan the rest of the bore. There's nothing that I can see that would prevent that bore from being replated.


Posted May 14, 2013 - 03:41 PM


thank you.

ill probably send it out then and see what can be done.
Any recommendations on places to send it I'm in northern ca

if I sent my head out would they inspect that stuff or should my local yamaha shop be fully capable of inspecting it.

Related Content

WR Camshaft Swap Info - last post by jamesm113

WR Camshaft Swap Info

  • 0 replies

100 hrs on 2014 yz450f, shim valves or replace them? by ttr230rider6

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • Hot  79 replies

yz250x vs 450 4t comparisons (preferably desert riding) needed by JakeNorthrupYZ450F

Dirt Bike   Make / Model Specific   Yamaha   Yamaha 2-Stroke
  • 9 replies

yz400f throttle bog by yz400fmaniac

Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • * * * * *
  • Hot  28 replies

Is the 2016 GYTR Yamaha YZ450F too fast? by Fryboy

Dirt Bike   Special Interest Forums   Pro Racing
  • * - - - -
  • Hot  241 replies

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.