250sx cam bolt removal

[whiteman350x]

Trying to tear down top end on a 250sx engine that has been sitting about 20 years. No carb on it, so intake had rust in it and you can see rust in cylinder thru plug hole. Of course the cam is turned with one of the bolts on the gear straight down. Crank will not turn at this point. I have filled the cylinder with atf. Rocker box is off so the valves aren't holding it. Timing tensioner is out. Don't have enough slack in the chain to slip the gear around. Really don't want to cut the chain. Any ideas on how to procede?

[shortline10]

I’ve run into this a bunch of times , I can usually finagle the chain off with a little prying . You can also try removing the cover on the stator side and use a 17mm socket to turn the crankshaft .
If you have some time use a 50/50 mixture of acetone and ATF down the plug hole to free up the piston .