I think that you tube video only apply's to the dohc model, may be wrong though???. Gear box oil changed today and it was quite rank looking compared to the stuff we put in. Linkage taken off, cleaned and greased etc. May be psychological but after taking it a short run it did appear much smoother changing gear. On closer inspection there was a wee bit of play in the linkage. I will have to update when this Scottish weather is a bit more tolerable to see if the problem is completely solved, however, fingers crossed!!!!