I have returned to trials after a break of more years than I care to mention and I am currently restoring a 1972 Cota 247. I have been receiving conflicting advice on the premix ratio using modern oils. Any advice would be appreciated. Also, what recommendations does anyone have for clutch and gearbox oils?

Thanks!!!!

What makes you think you will get unconflicting answers about premix ratios on this forum?

had exactly the same bike a couple of years ago. it'll jump out of first gear every now and again and the carb will be worn and most likely require a new slide as a minimum once sorted though a very competant bike 9 (i won my class first time out at a very muddy trial and i dont normally at that club or in the mud)

as for oil i used 100ml of PJ1 per 5 litres of unleaded

wow scatching my head for gearbox oils i remembered i have a manual for the thing here in the office so straight from the book..

1972 cota 247

clutch 200ml sae 20

transmission 300ml sae 90

if you need anything else drop me a line.

Regarding the oil for the Cota, I have the same book but you will have a hard time finding straight sae20 oil. I have been using sae 10w 30 for the clutch in my old Cotas and it has been fine. For the gearbox straight 80-90 gear oil.