well, i got the head and cylinder off today with not too much of a problem, turns out that the piston isn't seized, it's somewhere in the bottom end!!! NOT GOOD!!! WHAT DO I DO NOW???

i took some pics,Click on "250 R topend..." take a look and them me what you think

do i need a new head, or can i fix this one? probably better off just to get a new one??? what kind though, and what size???

HELP!!!

 

The head will be fine, just needs to be polished. I've seen a LOT worse!

I would think about tearing the cases apart, and looking in there for parts of the piston. It doesn't look too bad, but you don't want any pieces of ring or aluminum becoming airborn during high revs.

If I am seeing the pics correctly, you lost the top ring?
The piston obviously overheated too.

Are the ports chamfered at all? If they don't have a good chamfer on them, the rings may likely catch the edge of the port and either scrape the oil film off, or if really unlucky, break the ring off!

Did you do a proper plug check to check the jetting before "going for it" on your outing?

Give us a little history as to what led up to this, and the history/hours on the engine, and maybe we can shed a little light on what caused the problem, and what to do about it so's it doesn't happen again!

 

From looking at the pictures it appears to me you blew your rod bearings and they sucked up into your top end . This happened to me last year and i ended up with a total rebuild . Check to see if you can move the rod left and right . It should move slightly but not much also look down with a light into the bottom end where the rod meets the crank . Id say there is also loose bearings in you crank bearings which caused the lock up . As for the head you can polish it out i did and it worked fine . I ended up putting a new hot rod crank and rod in mine and bored it to 40 over . I had about 900.00 in it before it was done . But i replaced everything in it as i went . Good Luck

 

Did this have cooling problem?.this looks extremely "lean".

 

sell your 250r and buy a banshee

 

Your head is fine, just needs to be "neatened up" a bit.
The cylinder is fine also. Bore/hone and relief on the the exhust ports should take care of that. New piston/rings/ etc.

It looks like you had an exteme lean condition. What can happen here, even if you have it jetted properly is that the left side crank seal can leak (left side under the stator). This will let air in and lean your motor way out and smoke it all. I really think this when the bottom end seizes.

Take the piston off and junk it. No good to anyone now except maybe a recycler.

Move the rod, does it move back and forth easily? No=bad. Using the kickstarter (easy does it) see if you can rotate things and if they rotate easily. No=bad.
You need a new bottom end.

 

Yes the top ringis there, it is melted to the piston, i checked the plug before riding and it looked fine.I have about 4 hours on thet bike since i bought it a month ago, the moron ibought it from said it ahdn't been ringed in 2 years, since he bought it from the originl owner.

The rod is EXTREMLY loose, i was running klotz supertechnoplate 101 at 32:1 jetting was right on.

At this stage in the game, i'm thinking total rebuild, bottom end and all, i'l love this bike and want to get her running as soon as possible.

ANY HELP IS GREAT!!!!!

 

The decision you need to make now is, who is going to do the bottom end?
If you want a shop to do it, take it in and expect a large bill.
If you have the tools and are mechanically inclined and are willing to really dedicate yourself to it, you can do the work yourself.

 

I am pretty much in the same situation, only my motor isn't as bad. I decided that I would do the work myself with the help of a shop manual and people on this forum. So far so good, but I haven't tore into the bottom end all that much except removing the covers and clutch assembly. Another thing, if you want this done fast, do it yourself if you think you can, because a neighbors LT250R had a similar problem, and the shop took 2 months before the motor got back to my nieghbor.

 

Do it yourself,or buy a motor that's ready .