Oldfeller--FSO wrote on 12/31/69 at 16:00:12:Arthur provides us yet another indication of the need for the much finer filtration levels provided by folded paper type filtration.
BTW, my stock petcOck filter screen was partially plugged up with brownish varnish deposits last time I took my petcOck off. I think the fine brown powder he is finding in his tank are solids that parcipitate out of the gasoline (leftovers from the cracking process that are coming out of solution over time). I had the same stuff inside my tank.
Some refer to the brown stuff as rust particles, but I don't have any physical rust on the sides of my tank that I can tell and rust wouldn't coat a filter screen like this brown stuff can.
The screen type filters don't always cut it as varnish and fuel oxidation build up on screen surfaces (mainly because bikes can sit too much in the cold part of the year). The little bits of varnish powder that do make it through the screen mesh aren't going to do your fine jets any good and they are going to build up in your float bowl.
But opinions do vary. As do the approaches to keeping all the trash out of your carburetor.
Oldfeller
Wow. I never dreamed that I'd beens so lucky during 40 years of riding. How ever did I escape all these nightmare scenarios in all my bikes? I guess the Savage is a lot more "high tech" than even I knew.
A lot of the stuff in your tank has to do with past maintenance practices on your bike. Water, old gas and dirt. The photo above is not a photo of a petc0ck from Ron Ayers. That is mine after 7 years of use. See any varnish? (I know, I must have cleaned it up, right?)
Sure you get some dirt from the fuel, but the fact that things were stuck in your filter proves that it does it's job. Stuff that goes through the screen is actually able to go through your carb, too.
Let's not just talk about "fine" jets, either. Let's be more accurate. A main jet orifice (#145-155) is from 1.45 to 1.55 MM which means that the diameter is .057 to .061". That's almost 1/16". If you have stuff clogging the main jet, you've got bigger problems to worry about...(I'll let you calculate the other jets and orifices)
IMHO, if you want to over engineer it, that's just fine. However, that's doesn't mean that it's necessary to keep your carb clean. There is a drain on the bottom of your carb, too. Open it up from time to time, and let that fine stuff out.
Oh...and once you feel that your fuel is spotless and clear, don't forget that water still goes through the tank and inline filters. Water can condense from the air or come out of the gas pump, so regular maintenance is still a good idea anyway.
Good luck.