20-04-2019, 01:17 PM
Jon, you say "plenty of fuel visible coming through the modern inline filter at all times" what you are seeing is fuel filling the filter housing, you can from that, have no idea of the rate of flow. I have had personal experience of inadequate fuel flow from a bulkhead tank to a side draught carb. Liquid flow, gravity fed, through any orifice is entirely regulated by "head" which is precious little in your situation.
Remove the fuel pipe at the carb and direct it into a pint clean bottle, turn on the fuel tap and time exactly how long it takes for the bottle to fill. Any longer than 5 minutes and you have inadequate flow for bottom gear full throttle up a steep hill situations.
Many of the fuel taps have very fine mesh filters incorporated in the construction. Even when clean these severely reduce the rate of flow.
Remove the fuel pipe at the carb and direct it into a pint clean bottle, turn on the fuel tap and time exactly how long it takes for the bottle to fill. Any longer than 5 minutes and you have inadequate flow for bottom gear full throttle up a steep hill situations.
Many of the fuel taps have very fine mesh filters incorporated in the construction. Even when clean these severely reduce the rate of flow.