On Sep 6, 12:58*pm, Tman x@x wrote:
Flying a lot of 152s and 172s with carb heat lately. *When inbound, I've
been taught to pull the carb heat "on" downwind, hey actually use it as
a power control to slow the plane just a bit mid-field, and then more
importantly, just leave the thing on till clear of the runway and
cleaning up. *No matter what the temp, humidity. *And to have it on at
all times when the RPM is less than the green band. *Kind of a preventative.

A few times I have been coming in on short final and needed a burst of
power due to a sudden downdraft, or needed to pour on a little juice
cause my approach was coming up just a bit short. *Moving the throttle
forward 1/4 to 1/2 inch, i.e. giving it a little juice but certainly not
a go around type of thing, often times I would get a stumble, hicuup,
drop in RPM'S for 2-3 seconds before the horses responded.

Lot of convective turb lately and that power really comes in handy at
times on mid to short final. *Kind of a shocker when the engine doesn't
respond quite nicely.

This has happened on a few birds, especially on hot days. *I think
what's happening is the engine is just too rich, hey I've got the
mixture all the way in, it's hot (air less dense), and it's (way) hotter
with the carb heat on ( air much less dense), all enriching the mixture,
and when I put on a little power the accelerator pump in the carb
over-enriches the engine for just a little bit; causing the stumble.

Other pilots and the A&P just tell me to pour on the power a little slower.