This engine is on a mower and it is now a good time of year to turn it into a project. Here are the symptoms. Engine typically starts on first pull and runs fine initially. In the summer after a few minutes the engine develops a small popping sound. I hear the popping sound around once every five seconds or so. This continues for the duration of its operation. The last few uses in the late fall it was fairly cold - around 40 degrees F. Engine started as usual on the fist pull but did not start any small popping sounds until after around 30 minutes of picking up leaves. So in warm weather the light popping sound started after 5 minutes but in colder weather the same popping sound only developed after around 30 minutes of operation. If also did not pop nearly so frequently in the colder weather - maybe once every 45 to 60 seconds or so. I was looking for what might cause this type of symptom. I am kind of thinking it may be a carbon buildup on the exhaust valve but what do you think? This is a rather old Briggs engine in the 150cc size range. Steve

I have a Husky log splitter that uses a 6.75 hp Briggs & Stratton engine. Model # 126T02-0298-B1. It was running and just stopped suddenly. Thought it was bad gas so replaced it. Could not get it started. Pulled Carb and rebuilt it. Still would not start. Spark was good. Finally checked compression and "nothing". No compression at all. Pulled valve cover off the side and saw that exhaust valve was moving up and down but intake valve was not. No movement at all. Push rod did not move the valve. I pulled the head and engine looked OK. Some carbon but not much. Exhaust valve move in and out properly. Intake valve stayed closed. Never moved. Thought it was stuck, so I removed the retainer and spring and pulled the valve. Was not stuck. Moved freely and shaft is nice and clean. No pitting. Valve seat is great. Rotated engine and discovered that the push rod for intake is not moving at all. It is obviously in the closed position since the intake valve was fully closed. If it was "up", I would try and push it down. I have seen on another post where a slight tap on the push rod freed it up and a little penetrant oil got everything back into shape. Here, just the opposite. I feel pretty certain that I either have a bent push rod (or tappet valve (Sears), or whatever they call it on these small engines) or I have a broken or missing lobe on the camshaft. Before I pulled that cover, and went to all that hassle, I thought I would check for any words of wisdom from the experts.