do lawnmowers run on diesel?
There are a few commercial mowers that run on diesel, but they are few and far between. Both John Deere and Kubota make a diesel model.
john deere sit on mowers?
John Deere is not the company they used to be. I doubt they have a tensioner and if there is it has little, little adjustment. If the belt keeps breaking clean you better bring it in for some warranty work. If it shreds everytime your working it too ...
Red John Deere?
There were in fact some John Deere tractors that were painted red but they were generally only for special industrial orders in the 1960's.