I have had this kick back on starting with a number of these silly little sprinter mowers, when they decide they don't want to go over compression they can nearly break your fingers. I should have weighed the blade bar the other day when I had one off but they are so light, probably 100 grams and my belief is this is no different than trying to start a motor with the blade carrier missing or loose. I wanted to see if I could add some weight to it to see what it would do but the bloke wanted to pick it up so I just left it and warned him of the problem. I am thinking of adding some weight above the blade bar to see if this helps solve the problem. I'm also thinking that increased spinning mass weight may also help with some of these Briggs that have hunting issues . Anybody have any thoughts?
