It needs at least 70 psi to run.
scotts intek 6.5 starter cord replace
SAE 30
0.030
For a Briggs & Stratton Intek engine "PH8170"
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.
0.030"
120 is nominal
Even though an Intek is not shown, it would be the YouTube video below.
Try this site: http://outdoorpowerinfo.com/repairs/
48 oz oil capacity
try .030 unless it is an Intek OHV and then 0.020"
In many product descriptions I'm seeing 8.5tp engines as replacements for 5.5hp engines.