You can adjust the valves on your 17 horsepower Briggs and Stratton engine by turning the adjustment screws. The adjustments screws will determine how much fuel goes into the piston chamber.
Try watching the video in the link below.
The valve clearance is set by grinding the faces if there is too much clearance or grinding the tip of the stem if there is too little. If it is a OHV engine you can easily adjust the valves. Try going to the link below for a video that shows how to adjust the valves.
You do not state if it is a single or a twin (which it could be of either at that HP) so links to each below:
Yes They Do
Valves 21 hp Briggs and Stratton Intek V Twin can be adjusted by increasing the torque on screw band with a right rotation. This can eliminate some leaking problems.
If the valves are new you grind the end of the valve stem to the proper height . Otherwise you just clean the valves up real good and put them back in , there is no other adjustment .
This video will show you how: http://www.youtube.com/watch?v=NjzX-PUjKmo
The valve clearance for a Briggs and Stratton 406777 engine is typically set to 0.004 to 0.006 inches for both the intake and exhaust valves when the engine is at top dead center on the compression stroke. It's important to adjust the clearance when the engine is cold to ensure accurate measurements. Always refer to the specific service manual for your engine model for the most precise information.
To adjust the valves on a 15.5 Briggs & Stratton engine, first ensure the engine is cool and disconnect the spark plug for safety. Remove the valve cover to access the valves, then use a feeler gauge to measure the gap between the rocker arm and the valve stem. Adjust the gap as needed by loosening the lock nut and turning the adjustment screw until the correct clearance is achieved, typically around 0.003-0.005 inches for intake and exhaust. Reassemble the cover, reconnect the spark plug, and start the engine to check for proper operation.
Even though an Intek is not shown, it would be the YouTube video below.
If it is a Briggs and Stratton engine, it sounds like you might have to adjust the valves. There is a built in compression release that lets it crank over easier. If the valves are too loose it will not release the pressure.