VF500F Very Hard to Crank

Hey folks, I'm the (not so) proud (at the moment) new owner of an '86 VF500F with under 10k miles. Bought non-running of course (dead battery & busted ignition switch), but appeared to be in decent enough shape for a 28 year old sportbike.

Anyway, after popping in a new battery & ign switch, and doing some basic checks, I try to start it. No go. I pop the alternator cover, and wouldn't you know the crank wont turn over. I have an Oh Sh*t moment.

Luckily, with a little bit of persuading, I got it to turn over, but it still gets stuck at the same spot on every rotation, even with all of the plugs out. Would this be an issue with cams/valves? I would figure if that was the case it would only get stuck on every other revolution, due to the cams rotating at half the speed of the crank. However, knowing that cam/valve problems on these are common...

I have also put oil in the cylinders in case there's any seizing issues there. Spark plugs look good. Any insights?

The bike:

 

I should add that I usually work on 60's and 70's Hondas, and this the newest bike I've ever owned. Sad but true. DOHC, watercooled, V4, tubular frame? Downright space age!

 

Is the crankcase totally full of a fuelly smelling liquid? Did you drain and replace the engine oil before cranking?

 

It had been drained before I got it. Now filled with fresh oil.

 

Bring your own battery and a socket to fit the crankshaft nut (accessible through a small easy-to-remove cover) looking at any used bike, especially a VF500 !!! If it won't crank over and seems stuck like yours, it's only fit for parting out.

 

Ok, I popped off the valve covers and everything looks ok visually. I loosened all of the tappets to see if that would make a difference. No change. It still gets stuck 180 degrees off TDC 1.

 

Sounds like a hydro-lock to me. Did you check if the crankcase is full of liquid with no air space--old carbs can leak a full tank of fuel down into the bottom end.

 

Well now... it runs! After soaking in oil and lightening the load (loosened tappets, plugs out), the engine finally turned over pretty quickly with the starter. I re-adjusted the valves, buttoned everything up and bam! Started right away.

Now, after some more warming up, maybe another oil transfusion and filter is in order. Anything else I should be doing other than keeping a very close eye on everything?