In Reply to: 8N fuel flow posted by John in Mich on June 13, 2022 at 19:19:57:
The fuel flow rate isn't listed in any OEM manual. It is a formula that JMOR calculated from the technical data that is listed and is good to go. PM on the carb is an essential part of maintaining your machine. If you suspect a carb problem, the first thing is to perform the fuel flow test. There are a few items that can hinder carb performance. The OEM FORD/MARVEL-SCHEBLER Carb consist of three filters in the system. Two are located on the Fuel Sediment Bulb Assembly and the third, often the one that gets neglected the most, is a fine mesh screen attached to the brass fuel inlet elbow on the carb and feeds the fuel line from the Bulb. The easiest and first test should be to loosen teh fuel lien at the elbow, gently slide it off to the side, and then open the Bulb 2 turns to see if fuel flows unobstructed and fills a pint in 2 minutes. If it fails, the problem is upstream, possibly the Bulb, dirty gas tank, or plugged tank vent. If fuel line flow passes, reconnect and then remove the NPT Drain Plug on the bottom of carb base and repeat flow test. If it fails, the problem is internal and may be time to clean and rebuild the unit. Many times you'll find the brass fuel inlet elbow screen is the root cause if has never been cleaned. A lot of guys don't know it is even there. OEM Manual specifies it is part of the PM system every so often. Here's one that appears to have never been cleaned.