prawnboy

I have had this little gem for over 35 years. In that time the engine has never missed a beat. Although she hasnt been run for about 5-6 years, I attempted to fire her up a few weeks back and it ran really rough, wouldnt rev and spat oil out of the exhaust pipe. I thought it about time for a refresh. I am more than happy about stripping a single cylinder as I have done so with several others (Honda 125, Kawasaki 50) in the past. My problem is, the nut on the end of the crankshaft on the clutch side is being very resistant to being removed. The engine is still in the frame so as to firmly hold the engine still so I can apply leverage, but still it fails to budge and I have applied plenty of leverage. Can anybody confirm that it is normal RH thread or have I made a schoolboy error and it is LH thread? Clutch basket nut was no problem, although it is still fitted. Help!!