Bought the CB550K0 three weeks ago, US model bought from England with a seized engine.
Having raced karts for 15 years I thought an seized engine rebuild would be fairly easy.
So bike stripped down to the frame in 2 days.
Rocker cover off to discover that one the cam gear screws was down inside the head channel. no option but to split the cam chain and order a new link.
head off and inside pistons are at the top and outside pistons bottom. no movement in the crank at all.
Only 1mm on inside bores to fill with release fluids
soaked in parrifin for three days - no movement.
soaked in Diesel for three days still no movement - applied 2 heat guns until the diesel was bubbling - still stuck
soaked in Liqid-Moly penetrating oil and TQF and heated every night for 10 days.
last night got 0.5mm movement by rocking barrels front to back with a large screwdriver under the fins ay the rear and a 5mm steel plate under the front fins at the two raised points on the front of the crankcase.
Tonight same rocking again while my son tapped the pistons gently with a wooden block and hammer.
30 mins later barrels off - 2 x small ends tight.
next session tomorrow night