Notes on Briggs & Stratton tune-up

(From: (Willjim@gte.net).)

Once the air filter is saturated it must be wrung out. I typically place them in a paper towel and squeeze. Then possibly a second paper towel. No oil should be dripping out of the filter when gently squeezed. Chilten's B&S engine section says to simply squeeze the filter of excess oil - no mention of a paper towel, etc.

In adjusting the carburetor, Chilten says about 1-1/2 turns but 2 turns is my standard.

I get the engine running first - warm it up to general operating temp. No applied choke, air cleaner installed. Adjust the main jet if you can get it to run at rated speed - preferably under load (turn in to the lean studder, out to the rich studder then back in about 1/2 way between these extremes). Then adjust the idle, at idle - at no load - using the same operation as the main jet. You may then go back and repeat/refine the process a second time as the idle adjustment may affect the main a bit.

For the 92000 in particular (typical but refer to your specific engine model for exact specifications), from Chilten's second edition, "Repair & Tune-Up Guide for Small Engines" (successor to [2]):

• Plug type: 1.5"/2.0"
  • Champion CJ-8/J-8
  • Autolite A-7NX/A-71
  • A.C. CS-45/GC-46).

• Plug gap: 0.030"

• Point gap 0.020"

• Armature air gap:
  • 2-leg 0.006" - 0.010"
  • 3-leg 0.012" - 0.016"