Clogged jets

[FireFoxIV 58]

My 912 has always idled I little rough and I kinda pawned it on the carbs being out of sync. But last time I ran it, it idled so rough there was no way I was goin flyin. I tweaked the throttle arms to see if I could get it to run smoother, but no matter what I did it just got worse. So I dropped the float bowls and took out the idle jets, and what I found sure made sense why it ran roughly at idle and smooth at 2500rpms and up. 

this is the mixture screw

[marcusofcotton 51]

Yikes, what is it from? What does the filter/gascolator look like?

[1avidflyer 1983]

I'd have a heart to heart talk with you fuel filter... As far as syncing the carbs, I just went through that with my 912, and used a single vacuum gauge.  Lines going from each intake manifold to a T, with valves in both of those lines.  The other line went to the vacuum gauge.  One valve open, one closed and then reverse the valves to compare the difference and adjust accordingly.  I ran across something on youtube that will probably do even better once you are close.  JImChuk

 

[dholly 718]

Yuck! Curious when the last time the carbs were cleaned or rebuilt? Fuel filter replaced? Do you have finger strainers at the tank outlets? Do you use a Mr. Funnel or other fine filter when handing fuel? Did you ever determine the source of this contamination, or exactly what it was?

[FireFoxIV 58]

Yuck! Curious when the last time the carbs were cleaned or rebuilt? Fuel filter replaced? Do you have finger strainers at the tank outlets? Do you use a Mr. Funnel or other fine filter when handing fuel? Did you ever determine the source of this contamination, or exactly what it was?

The carbs where rebuilt February 2019 with 50hrs on them. I think there's finger screens in the tanks but it's hard to see since I cant get the fitting out because one of them is bonded to the the female fitting thats glued to the fiberglass tank. And the other one is a nylon fitting that's stuck. The only other fuel filter in the whole fuel system is the screen in the gasgolator. I don't use a filter when I'm filling, I know I should, but the jugs I use are for filling my airplane only and there clean, know tellin about the fuel though. I have know idea what it is or where it came from

[1avidflyer 1983]

Might not be a bad idea to have a filter right after the fuel pump, at least for a while till you get the junk out.  I always run my fuel through a Mr Funnel, but I'm always filling up at home from cans.  JImChuk

[dholly 718]

I had a ACS 'Homebuilders' gascolator on both my Kitfoxes and how that crud could get thru the gascolator is a big question to me. Is the gascolator filter screen in place?

Just a FYI, ACS has both high and low pressure versions with SS screen filter mesh sizes 74 or 122 microns respectively and a gasket that in not ethanol proof. I replaced the gasket with the E-proof gasket and finer SS 74 micron screen on both. 74 micron is about the dia. of a human hair, definitely should catch the crud you found. Another FYI, the low pressure gascolator is rated to max continuous fuel pressure of 3lbs. but seems to work fine with slightly higher psi elec boost pumps.

[FireFoxIV 58]

Might not be a bad idea to have a filter right after the fuel pump, at least for a while till you get the junk out.  I always run my fuel through a Mr Funnel, but I'm always filling up at home from cans.  JImChuk

Im geting a inline fuel filter to put in downstream of the fuel pump, and I'll probably flush all the fuel lines to make sure I get all the crud out

I had a ACS 'Homebuilders' gascolator on both my Kitfoxes and how that crud could get thru the gascolator is a big question to me. Is the gascolator filter screen in place?

Just a FYI, ACS has both high and low pressure versions with SS screen filter mesh sizes 74 or 122 microns respectively and a gasket that in not ethanol proof. I replaced the gasket with the E-proof gasket and finer SS 74 micron screen on both. 74 micron is about the dia. of a human hair, definitely should catch the crud you found. Another FYI, the low pressure gascolator is rated to max continuous fuel pressure of 3lbs. but seems to work fine with slightly higher psi elec boost pumps.

there is a really fine screen in the gasgolator, the pieces of FOD are quite abit bigger than that screen. It almost looks like the fertilizer that i put on my runway, at least for color anyways

[ChrisBolkan 130]

I really like that balance test scheme on the video!