Hi All,
Need some help here. Very familiar with automobiles, not so much with small engines. Just fixed needle and seat in carburetor of briggs 28Q777 single piston 15.5 (?) HP engine. Was severely leaking fuel into oil. Also did a head gasket, valve cover gasket, adjusted lash on the valves and air gap on the armature. When running, the engine runs VERY good, strong and smooth, not burning anything, sounds good...excellent.
However, this engine has ALWAYS been a bit difficult to start. I noticed something very interesting tonight. When the engine is cranking (electric start), there is NO spark that's occurring. I have the spark plug out, gapped to 0.030" and grounded against the head. However, immediately after releasing the key (so the key position is in "run") there is spark visible. I tried this many times, and always the same, no spark when the engine is cranking, but spark when I release the key. Thinking back, this has always been how the engine was (inherited the mower about 6 years ago). It will start when I release the key and the engine catches, and fires right up and runs like a top.
Curious, I disconnected the electrical connector to the magneto, the one I think is responsible for grounding it out. Now I get spark when I'm cranking, but the engine won't fire. I suspect it's because this is also shutting off fuel through the solenoid in the fuel bowl.
So, Briggs and stratton geniuses out there...what do you think is going on? What would be causing the magneto to ground in the crank position? If you'd like me to test something, please indicate what you need and how you'd like me to test it.
Many thanks,
Brian
Need some help here. Very familiar with automobiles, not so much with small engines. Just fixed needle and seat in carburetor of briggs 28Q777 single piston 15.5 (?) HP engine. Was severely leaking fuel into oil. Also did a head gasket, valve cover gasket, adjusted lash on the valves and air gap on the armature. When running, the engine runs VERY good, strong and smooth, not burning anything, sounds good...excellent.
However, this engine has ALWAYS been a bit difficult to start. I noticed something very interesting tonight. When the engine is cranking (electric start), there is NO spark that's occurring. I have the spark plug out, gapped to 0.030" and grounded against the head. However, immediately after releasing the key (so the key position is in "run") there is spark visible. I tried this many times, and always the same, no spark when the engine is cranking, but spark when I release the key. Thinking back, this has always been how the engine was (inherited the mower about 6 years ago). It will start when I release the key and the engine catches, and fires right up and runs like a top.
Curious, I disconnected the electrical connector to the magneto, the one I think is responsible for grounding it out. Now I get spark when I'm cranking, but the engine won't fire. I suspect it's because this is also shutting off fuel through the solenoid in the fuel bowl.
So, Briggs and stratton geniuses out there...what do you think is going on? What would be causing the magneto to ground in the crank position? If you'd like me to test something, please indicate what you need and how you'd like me to test it.
Many thanks,
Brian