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YZ Bottom End Rust Spots

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To start off I bought this bike about a year ago for $1500.  It's a 2001 YZ250, have no idea when the top or bottom end was redone last.  All I've done to it was clean the carb, new air filter, and swapped the oil.  

 

I've probably put 10 hours or less on it since I bought it, haven't had time to ride it much since I've been at college.  Anyhow I've noticed that after I have warmed the bike up and I get into a tight spot for whatever reason and manage to stall it, if I don't start it back up within 5 minutes it is an absolute animal to get started again, pretty much have to roll start it.  Not sure if it's flooding real bad after it stalls but I was riding the other weekend and I stalled it trying to back out a mud hole and I was so tired after getting it out I waited probably 10 minutes before I went to try to start it again.  I did shut off the fuel while I was waiting but I could never get it started again, I tried and tried, even waited an hour and tried, nothing.  So I ended up having to push it 1/2 a mile up out of the woods.  About an hour and a half later tried starting it and it almost went after the fifth kick but then nothing.

 

I've been wanting to pull the jug to just check out the condition of the top and bottom end and I need to clean up the powervalve as it's currently leaking lots of spooge so I thought this was a good excuse if any.  Here's what I found, looks like there may be some blow by and I found some interesting rust spots on the crank.  What do you guys think?  Not sure how moisture may have gotten in there, the only thing I could think is that it may have been sitting for quite a long time.  Never replaced a bottom end before, it does not seem very smooth when I move the piston, wouldn't say really rough but not really smooth like a fresh bearing.

 

 

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When in doubt, put new stuff in. You're halfway there anyway.

That top end is gone.

I'd see what I could do about getting rid of that rust and clean out the crankcase area. It's possible some rust has made it's way up to the top end.

Time to freshen 'er up. She'll purr like a kitten when she's done...and you can be confident in it.

 

As always...check your jetting...not worth the risk of running a brand new motor with bad jetting.

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Yea I was gonna do the top end regardless, I just wanted to know what people's thoughts were on the bottom end.  I've never seen rust like that on a crank before in a bike that has been running.

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