Potash123 26 #1 Posted June 29, 2018 I ran out of normal petrol for my Mountfield OHV mower. I put in some Premium Grade petrol in it laced with Castrol R40 which I use for my BSA Thunderbolt. What a difference, running slightly faster and pulls like a train. Will it do any damage. Starts better too !!! Share this post Link to post Share on other sites
Stormin 4,458 #2 Posted June 29, 2018 I would think if it's good enough for the Beeza, then it should be more than good enough for your mower. Share this post Link to post Share on other sites
Wristpin 400 #3 Posted June 29, 2018 Might run a bit hotter both due to the higher octane and the added oil making it a weaker mixture, fuel to air wise. very unlikely to do any harm unless worked hard for a prolonged time so revert to standard unleaded when convenient. Share this post Link to post Share on other sites
Potash123 26 #4 Posted June 30, 2018 Thanks lads nice to be back on here. Regards Colin Share this post Link to post Share on other sites
