"old" Tenere piston stuck after storage
 

I recently wheeled my 1985 XT600 out of the garage for the first time in about 3 years and the kickstart is locked solid. The piston seems to be seized in the cylinder, Ive tried push starting and there is NO movement. I rebuilt the engine and only rode about 300km before putting it into storage for way to long. I know, I should have turned the engine over from time to time but ....
What to do now, should I open up the top end and have a look inside? What am I likely to find ? Rust? Disaster?
My poor poor bike. .

ATF and acetone mix, pour some down the plug hole and let sit for a couple days. Even after breaking it loose there may be a bad rust ring that will always be rough. It may smoke from now on also.

I had gotten a parts bike that had no exhaust on it and it sat in a shed for several years, it also couldn't be kicked over so I dumped PB Blaster into the cylinder, then a day later some ATF. I also sprayed the valves with PB through the exhaust and intake ports to make sure they weren't seized. After a couple days it came loose and fired up pretty easily then. Smoked some for about 10 miles but actually ran good, still does.

That is excellent advice!
Fill up the cylinder .... let it soak a couple days. Also, make certain the cylinder is not filled up with FUEL! If if is ... then you have Hydro-lock, just drain oil to make sure.

Once motor turns over ... do as advised above ... pull head off for a rebuild.
The cylinder may be shot, rings too??

WD40 is also a good rust dissolver. Dump some of that in there too! :mchappy:
Good luck!