I have just been looking through Sherco's website and on their setup and lubrication guide they recommend a fuel/oil ratio of 80:1, I was told to use 50:1 by the guy I bought the bike off.

Which ratio should I use, or is there any other recommendations?

The bike is a Sherco 290 2002.

I think 50:1 is too much with a synthetic oil.

I use between 75 and 80:1 and run fine for 2.5 years.

Won't do any good to have more oil in there. Can make it run hotter.

Thanks, I'll try 80:1 next time.