Questionstarter motor kickback I have adjusted valve clearances also checked fly w key I removed the key and replaced the flywheel in a retarded mode. result perfect. Then i replaced key . returned to severe kickback
Answerbernie
Try some of these tips
You should only need to do this if you are replacing or grinding a valve. In most cases, the valves are undamaged but may appear in poor condition due to carbon buildup - which can be removed in-place fairly easily.
Remove the valve cover on the side of the engine next to the valves.
Use a feeler gauge to check the gap between the valve lifter and valve stem with the valve lifter in the relaxed - lowest - position. A typical value is .010 inches. Excessive clearance will require replacement of the valve or valve lifter. There could also be too little clearance - which is also bad - but the valves stems can be ground down to repair this problem which is either a defect in manufacturing or a result of a cam shaft replacement which is oversize.
Use a valve spring compressor to remove pressure on each valve.
The retaining clip or split cup should now be free. Remove these.
The valve should now slide out.
Loosen the valve spring compressor and remove the spring and any other hardware. Don't interchange the intake and exhaust valve springs.
Remove the built up carbon deposits from the valves and valve seats using a soft metal scraper. Some WD40 may help to loosen the caked on carbon.
Inspect the valves for serious burning or pitting especially on the seating (angled) surfaces. Once free of any carbon, they should be smooth and undamaged.
Similarly, inspect the valve seats for serious burning and pitting.
Inspect the springs for rust or other damage. Stand them on a flat surface and check for serious droop/tilt. Measure their free length and compare with your engine specifications. On old 3.5 and 4 HP Briggs and stratton engines the cam acts weirdly and opens the exhaust valve slightly on the compression stroke thus loosing air and fuel mixture and compression. This is probably due to wear of the valve or valve seat resulting in the cam pushing the valve up when it's really not supposed to be touching the tappet. You need to pull the head off and crank it slowly and watch the exhaust valve, if both valves close and then the exhaust valve pops up, an adjustment is required. To fix this grind the exhaust valve tappet side down 0.5 MM put the valve back in and check it out if it still does grind a little more off. the engine will run smoother than before and a little better
Note that many small Briggs and Stratton (and other) engines include a compression release feature to make starting easier. This has a similar effect in that it opens the exhaust valve during part of the compression stroke reducing the effort needed to pull the starter rope. This should not be confused with what Brian is describing, above. At normal operating rpm, the governor moves a secondary piece on the exhaust valve cam out of the way so that the behavior returns to normal. Unfortunately, unless the crankcase is open, there is no easy way to determine whether the compression release is present on your engine without a service manual.
