# 675 Series muffler install



## ksfoster (Apr 4, 2010)

I have a 2009 Troy-Bilt lawnmower with a Briggs & Stratton 675 series engine. The muffler has a laver on the back of it that is thermostatically controlled. I am unable to figure out where this lever either connects or fits into the scheme of things on the engine so that I can replace the muffler. Does anyone have any experience with this particular issue?? Thanks in advance for your help! My wife is going to kill me if I don't fix her lawnmower...


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## WayGroovy (Sep 4, 2010)

I had to remove the top metal cover to the engine to replace mine. Remove the oil fill and check tube, one bolt. Remove the upper engine cover, Two bolts in the back, two on front. Now you should see a plastic lever going across the top of the engine. When the engine exhaust gets hot the metal bar moves forward. The metal bar pushes this plastic lever towards the front of the engine. The plastic bar pivots around a bolt. A spring holds the plastic bar normally back. The other end of the plastic bar rotates a small valve on the intake. When the engine gets hot, the air intake closes, causing the engine to shut down.

My 675 is acting up. It will start fine, then it starts to stutter, and will die under any amount of load. I have manually held the air intake valve open and this prevents the stuttering. I can't tell if the spring pressure on the plastic bar isn't good enough, if there is an actual temperature issue, or if the temperature sensor has gone bad and is activating at a now lower temperature. I also don't know where to go to buy parts.


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