1972 Briggs 5HP Model 130202 with brand new OEM Briggs carb
This is the model with the "Pulsa-Jet" carb that bolts on top of the fuel tank. There is only one adjustment screw for the fuel mixture.
The repair manual states that the starting/default position for the screw is 1.5 turns out to get it to start and run- which I have always done. Then, you adjust in or out as needed to get it to run the best.
On most engines I have ever done this ends up being from 1-1.5 turns out. On this particular carb the best setting is (only) 1/2 turn out! Any more than that and it sputters black smoke when you go to open the throttle quickly. It starts, idles, and runs best at the 1/2 turn out setting.
Should I be concerned?
Any idea why it runs so well at only 1/2 turn out?
Am I worrying too much and should just let it go and move on?
Thank you,
Michael