View Full Version : What are these droplets on my throttle blade at idle???

06-28-2013, 10:03 PM
After rebuilding my 4160, I've noticed that my idle is still slightly rich. I lowered the float below the 'parallel' level and it seems to have helped, but not completely eliminated the problem.

Upon inspection tonight, I noticed these droplets on the primary blades only. Is this an indication of something? I swabbed them with a q-tip and smelled them and they smell like fuel BUT I'm wondering if it could simply be condensation with a lingering fuel smell.

I was expecting a flooded condition to leave much bigger drops. Has anyone seen this before?


06-28-2013, 10:45 PM
I bet condensation - I've never seen a petroleum product bead up like that.... but I am just guessing.

06-28-2013, 10:57 PM

I saw that on a 351 I had many years back.

Humid conditions along with cool temps can actually form ice in the venturies.

06-28-2013, 11:39 PM
Old planes had carb heaters for a reason ....

06-28-2013, 11:55 PM
Where are your idle mixture screws set at. Should be 1.5 turns out from lightly seated +/- 1/4 turn.