I have just purchased a Montesa 315 RZ, it seems to be missing a chain tensioner, where can I purchase these from, and are they expensive? There seems to be a bit of play in the brake discs, can this be resolved? What is the correct mixture for the petrol to oil mixture, I was told it is 80:1 with fully synthetic 2 stroke oil, is this right? can anyone advise me which 2 stroke oil to use? and also the recommended gearbox oil, and how often it should be changed. Thanks.

Not sure on tensioner other than Sandifords. If it is just the pad then this is standard with all modern bikes so any dealer. Mont stuff seem good value from main dealers. Brake disc float so don't worry if only a mm or 2.

Having run 3 315s over 8 years found Castrol TTS fully synthetic very good, approx 50 to 60 to 1. 80cc to 4 litres. Ran ATF in my clutch/gearbox and worked well. Change every 6 weeks as cost is minimal. If you change gearbox oil to other than ATF or Std Elf oil suggest going practicing before as oil has major effect on clutch feel and drag. Enjoy, Top quality bike if if not so fashionable now.