Topic: fuel petcock filter not filtering too well

[kurtkarram]

I have a project cb500, with a brand new bolt on dual spigot petcock. It has the circular metal mesh filter on it. It is not leaking through the tank bolts. The tank is relatively clean, has a couple of small rust patches. Opening up the carb bowls, there are rust sediments in every one. Most of it is fine powder like, but there are some bigger chunks. Opening up the cup on the petcock shows some rust that it has caught.

I'm curious as to how effective these filters are? Should I remove it and switch to inline filters? i know I shouldn't run both. Any other methods to make it more effective? Different type of filter?

I know the obvious answer is to clean the tank but it's already very clean. It's just concerning how much it's letting through.

[newday777]

You need to derust your tank!
I do the electrolysis cleaning method, 3-4 days, followed by Evaporust, 2 days, then rinse with diesel fuel(the oils in diesel fuel prevent flash rusting)4 times, to get all moisture out, then coat the tank with 2 stroke oil to protect it from rust.
Then the tank filter will do it's job.

[HondaMan]

The petcock filters work very well. The inline filters always (and I do mean always) restrict the fuel flow, particularly noticed during modern interstate travel at speed. With the CB550 in the mountains here in Colorado, at high altitudes (8000+ feet) the typical 550 with an inline filter(s) will not be able to run 60 MPH or more for lack of fuel flow. The 750s with 1 spigot outlet (late K4 onward) act similarly, not being able to hold interstate speeds of 80 MPH out here when inline filters are used. I have "magically" fixed 4 of these situations in the past 8 years by installing new fuel lines, properly routed, and without the inline filters on 550s and 750s.

I haven't [yet] had to 'fix' a 750 with dual fuel hoses and inline filters, though. I haven't seen one of those!