Two Stroke Motocross

TSM Racing => YZ Project 2018 => Topic started by: rsmith on May 21, 2018, 08:42:41 PM

Title: First Look
Post by: rsmith on May 21, 2018, 08:42:41 PM
We picked this good looking used 2013 YZ250 up to document the process of inspecting and refreshing a used bike.

Longer term it is going to be a "test mule" for product tests and will be part of a really cool, but as yet to be announced, series. 

Stay tuned.

(http://www.twostrokemotocross.com/images/TSMProject13YZ250.png)

--Ron.
Title: Fork Service Surprise
Post by: rsmith on May 21, 2018, 09:09:17 PM
I started on the tear down and evaluation. No surprise the fork seals were leaking, I noticed that when we were evaluating it.

(http://www.twostrokemotocross.com/images/YZ250LeakySeals.jpg)

This was a bit disappointing but not surprising,  the original owner said he never serviced the forks.
(http://www.twostrokemotocross.com/images/ForkOil.jpg)

This on the other hand was a completely unwelcome surprise.
(http://www.twostrokemotocross.com/images/FreePiston.jpg)

From what I learned exploding free pistons aren't all that uncommon. Supposedly they fixed this after 2009, but this is a 2013 so draw what conclusion you will from that.

The upside to this is that a couple of different companies makes aluminum free pistons for it that are open on the sides to prevent the over pressure that causes this failure.
(http://www.twostrokemotocross.com/images/FreePistonReplacement.jpg)

Next time I will show you why it is important to take your brand new bike apart before you ride it.

--Ron.

Title: Re: First Look
Post by: OldNSlow on June 05, 2018, 10:33:43 AM
Nice, cant wait for this tear down and inspect/make right continues !!

OnS