QuestionI've got a Briggs and Stratton 11 HP L head (horizontal) on a mower I'm trying to fix.
When I check the valve clearance at 1/4" past TDC I have the correct clearance .007 (aluminum block), however, during the ENTIRE compression stroke, the intake valve is open a few hundreths and it's blowing the fuel out of the carb. How could this possibly work? How could the engine ever NOT blow its combustion mixture out of the carb?
I've heard of a easy-start system that releases the compression when rpms are low (during crank) but I'm not sure if this engine has that. I pulled it off the mower and opened up the bottom end, and I don't see any mechanism in there that would do any such thing. Also, I thought those mechanisms worked on the exhaust valve. Anyway, on the cam, I only see the two regular lobes.
I've checked to make sure the flywheel key is in good shape, and the two dots on the cam are lined up the way they should be.
HELP, I don't know where to go from here!
Model 252707 Type 0621-05 Code 91081611.
AnswerChris
Are you checking the valve clearance at Top Dead Center (TDC)have you replaced the Intake Valve Seat or the exhaust seats?
This engine needs to have the following adjustments on the valves Intake .005 - .007 Exhaust should be .009 - .011 There may be a small obstruction holding that valve open.
You do have the compression relief (Easy Start System)A flooded engine, most likely due to extended unsuccessful attempts at starting or a defective carburetor (float valve stuck open or gas-logged float) will result in inability to start as well and a distinct odor of gas. You might find raw gas coming our of various orifices - air filter as well as exhaust. (Note that in severe cases, enough gas gets mixed in with the oil to significantly increase the level in the crankcase and reduce the effectiveness of the oil. This will require an oil change.
