XJ600 - I connected the battery and turned on the petrol gave it half choke and it fired up third jab. However, the clutch would not free up whatever I tried. My friendly bike shop said if it's been laid up for a while ( it has) the plates may be stuck up with old oil or oil that is too thick.
I bought some modern 10/40 a new filter and a sump plug washer and he is ordering a clutch cover gasket for tomorrow. Back home I drain the oil and yes it looks like straight 50 grade. I removed the clutch cover and pulled out the pates which were very stuck together.
I'll pat them down with kitchen roll to remove whatever in on them and then apply some 10/40. True to form, as found on the rest of the bike, one of the clutch spring bolts was a rather badly mauled Phillips head thing. I had to rumage in my nuts and bolts boxes to find one that looks like an almost perfect match. Being a hex head, like the originals, I can at least apply the correct torque to it now.