push lawn mower not starting

[topgun129]

i was planning to grind down the valve end like 1mm and then recheck if it creates the proper valve clearance. basically i have a clearance tool like in the attached image and took the thinnest one and i could insert it thru where the valve closes against the head (right next to the piston), however with the exhaust valve i could not insert it thru (meaning a very tight close). seems like because of the lack of tight closing of the valve it creates a lack of compression. the exhaust valve closes tight and has valve clearance.

i took the image at top dead center (piston at top and valves fully closed). the bottom valve has a very small clearance while the top one does not at all (kinda hard to tell in the image).

 

[Scrubcadet10]

 

[bertsmobile1]

1mm will be way too much
Firstly make sure you are on the firing stroke and B&S recommends to go 1/4" past TDC
Too easy to to be at TDC exhaust stroke and really stuff things up
THe head should come off & the valve come out .
Valve lash is set by shortening the valve stem ( increases ) or cutting the seat deeper ( closes the lash )

In use the exhaust valve seat wears away which closes down the gap till there is nothing left .
Because it is a strait push ( no rockers ) if the valve lash is just 0 then you take .007" off the stem not 1mm
Pop the valve back in and measure the gap while pushing the valve in as hard as you can with your thumb
With my hands I find around 0.015" measured this way gives me around .009" with the spring on

 

[topgun129]

ok sounds good. i'll recheck with 1/4" past TDC and then if same result then i'll give the valve a very very light grind on the stem. thanks.