05 Seized, what to look for?

[kitscott]

Bought this 05 last year to follow my son around on his KX65.  Have done regular maintenance and it has been great over the last year for trail riding and keeping up with my kid, no racing.  Anyway, in my mind, it wasn't that long ago that I changed the oil (my memory being what it is...) so I was going to change oil after riding last week (and didn't check the oil level  ).  After riding up a logging road for about 45 minutes, we turned around and were heading back to camp when I let off the throttle and coasted downhill for a minute.  Before getting back on the throttle, it made a sound like a playing card stuck in the spokes of the wheel (except louder), then it seized.

 

I've done some searching in this forum and found some great stuff, but I'm starting to feel a little overwhelmed with it all as this will be a DIY fix.  

 

I have drained what oil was left (about 3/4 of a cup) and there didn't appear to be any grit or metal in it.  There also weren't any little bits of metal in the oil filter, but I'm wondering how long it's been since any oil went through the filter with that little bit of oil in the case.  I removed the spark plug and put some oil down the hole and after about 24 hours was finally able to move the kickstarter, so I can now move the engine enough to get to TDC.  After removing the valve cover, there is some bluing and pitting on the cam, but that's as far as I've gotten.

 

So, my questions are:

1. I assume that as I begin to take the top end apart, the damage will be obvious, but for those of you who have done this work before, what are the key things to look for and their priority?
2. Once I tear it down to see what the head, cylinder, and piston look like, is there some trick to checking the bottom end (Service manual is on its way)?
3. If the damage is limited to the top end, how affordably can a DIYer get it back up and running?  Maybe a best and worst case...?  I'm not really looking to upgrade anything (previous owner had already put Kibblewhite valves in, so I would replace them with Kibblewhites if necessary), just to get it back to its pre-seized condition.
4. Any other words of wisdom you'd be willing to share? (besides checking the oil before every ride  )

Thanks...

 

 

[Mike in OK]

Sorry for your troubles, I bet that was a long push back to the truck. I seized mine once while riding with my son too. If your's is like mine you will get lucky and all the damage is in the cylinder, and a top end kit will run under $200 for piston, rings and a gasket kit. No metal in your oil is a good sign though. Once you get in there you can check your rod play, you should have (practically) zero up and down play and a small amount of lateral play, specs will be in the book. If you have to split the cases then that's a whole other matter and someone more experienced than me will have to chime in on that one. Hope for the best and plan for the worst!

[Mike in OK]

Oh, and post pics of what you find, especially the cam shafts as it will be easier for us to troubleshoot with pics.

[nesc103y]

If you only got 3/4 cup of oil out of it you probably seized it due to lack of oil.

you should have got around 600cc if you drained the correct drain.

Bluing of the cam lobe kind of confirms it ran out of oil.

This is about the worst thing you can do to the motor.

Every lubricated surface would be metal on metal with no oil pumping. Including the oil pump.

Are you sure you drained the engine oil and not the transmission?

[MatthewMCRepair]

Here are rebuild vids for an 07' but should help you out for your 05':

 

http://www.howtomotorcyclerepair.com/07-crf250r-engine-rebuild-bottom-end/

[Mike in OK]

Here are rebuild vids for an 07' but should help you out for your 05':

http://www.howtomotorcyclerepair.com/07-crf250r-engine-rebuild-bottom-end/

Hey Matt how do I get to the rebuild part(s)?

Edit: never mind in found it.

Edited June 6, 2014 by Mike in OK

[kitscott]

Ok, it's been a week (or more) but thank you all for your comments and interest.  Here's where I'm at so far.  The cam looks like the culprit. You can see the bluing in this picture.

 

 

And this is the worst of it where the intake lobe nearer the sprocket is deformed:

 

 

Here's the lifter from that side:

 

 

I have taken the head off and the piston and cylinder "look" ok.  I'll be checking tolerances and taking pictures of those.  Meanwhile, without the head and the cylinder there, the bottom end moves very smoothly with no play in the rod (except for that little lateral play that Mike in OK said would be there).  

 

I'd be interested to hear your experience if you've seen this before and would take recommendations for reasonable, relatively low-cost options for replacement parts.

 

Thanks.

[nesc103y]

You can probably get it running by replacing parts.

But your in for a world of shit down the road.

A no oil failure is worse than a greanded motor.

I've seen enough of both to know.

If you buy new buckets chances are they will not fit in the guides.

every heated surface will have a similar issue.

 

I just rebuilt a grenaded 450 with a new bottom end that I picked up off ebay for 500 to my door.

you should consider a similar option.

[bucket list]

Ah, no disrespect Kit, but i had to laugh when you said " the cam was the culprit". It was just the innocent victim of the real culprit, LACK OF OIL!  The cam and bucket was just the first parts to cry " UNCLE ". AS 103 said there is probably many more parts worn to the point of near failure. You should be using the service manual and measuring every oil related part, reletive to the service limit, i mean everything, other wise you will see much grief down the road.  Just warning ya.

 

And i agree, finding an engine that hasn't had an oil related failure my be the better option.

Edited June 11, 2014 by bucket list