hi guys . i have a 12 hp synchro balanced model 281707 type 0411 briggs . engine starts right up but the whole engine vibrates like crazy , i unbolted the engine off the riding mower frame and took the pan off . i could see the side of the outer counterweight was rubbing on the side of the crankshaft gear . counter weight has a lot of movement toward the flywheel and the bottom pulleys, there is a miniature conn. rod look alike holding the weights and at the end of the rod there is nothing holding it thats where the weight movement is coming from , is there suppose to be a bolt there? at the other end of the rod there is a long bolt that thru from the outer - rod-and inner weight. but no bolt at the other end of the weight rod. i went to the part list on www.briggs
& stratton and it does not show a bolt there.