Gently remove the rod from the crankshaft pin.
You might need to rock the crankshaft back and
forth to help the rod pop off.
When installing the liner, be sure that the
notch in the flange aligns with the pin in the
case, and that the liner seats all the way down
into the case.
crankshaft pin, and let the piston fall out
gently onto your hand or workbench (see
the photo). As you can see in the picture,
the engine that I used for demonstration
had a lot of carbon buildup on the top of
the piston and the head. This will all be
gone in a few seconds.
My weapon of choice for carbon
removal is the Mr. Clean Magic Eraser.
Mike Willcox turned me onto this
miracle sponge. Cut off a small piece of
the Magic Eraser and slightly dampen it
with water. Applying gentle pressure, rub
the head and piston top to wipe away
the carbon buildup.
As simple as that, your head and
piston top are shiny—like new. Now you
simply need to wipe the parts dry and
reassemble the engine.
When you reinstall the piston, be sure
to do it with the proper end facing back.
On a Fora engine, for example, one side
of the piston has a longer skirt. This side
always faces the rear. Before you push
the connecting rod onto the crankshaft
pin, add a few drops of oil to the pin
(you might need to rock the crankshaft
back and forth a little while gently
pressing the rod onto the pin).
Next, install the cylinder. It is crucial
that you have the cylinder properly
rotated to align the ports when you
push it down into the engine. On many
(most) engines, there is a small pin in the
case that keys into a slot on the flange of
the liner to fix the alignment. Make sure
that when you push the cylinder into
the case, the pin goes all the way into the
Finally, throw a few drops of oil into
the cylinder, set the head back in (being
sure to replace all of the shims that
were there when you opened it up), and
reinstall the backplate. Be sure that all of
the shims are seated flat on the flange of
the liner and not bent or sitting askew.
Double-check that the backplate screws
That’s it. Your engine is now clean
and ready for action. In a future article,
I will discuss how to clean and change
Finally, I just want to give a big shout-out to Lance Matassa, Arlene Pyles, Jeff
Hanauer, and the whole Phoenix crew
for putting on another great F2D March
Madness competition this spring. This
year we had the biggest turnout to date,
with 34 entries in triple elimination
F2D. We had many exciting rounds and
finished at dark.
The final standings were Mark Rudner,
first place; Cary Minor, second place; and
Alex Prokofiev, third place. In Friday’s
F2D Fast competition, which also had
Minor took first place, while Jeff Johnson
and Chuck Rudner placed second and
See you at the Nats!
Miniature Aircraft Combat Association (MACA)
Mr. Clean Magic Eraser
124 Model Aviation JULY 2017 www.ModelAviation.com
CONTROL LINE COMBAT