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It is a Briggs and Stratton. I have studied it by taking the top cover off and it seems as though something may have snapped when the cord handle whipped back in. The spring is not broken and I can tease the cord fulyl out by inserting a screwdriver between top of the cord reel and the cover. ie by depressing the reel. I think maybe a (ser) clip may have snapped as every time I allow the cord to wind back in which it does easily, it will only pull out a few inches without jamming. When I depress the cord reel, I can tease the cord out again. Any advice welcome. I can't undo anything more as the cord reel is inaccessible being fixed by rivets instead of screws.