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16
Never remove the butterfly valve from the throttle lever shaft so as to ease the fitting
or soldering of a larger lever. The reason is, that the manufacturer spreads the end of
the small screw, so that removing this screw damages the threaded hole beyond repair,
and re fixing the butterfly valve safely is practically impossible. Either the shaft breaks,
or the loose-fitting screw drops out and is sucked into the engine, with the result you
have a heap of scrap on your hands.
The choke valve can be operated with a servo if required. Do not remove the spring
and ball bearing selector for locking the choke spindle. A normal servo can overcome
the resistance without a lot of effort. With mini servos set the servo throw on the
transmitter to the maximum value, i.e. 150% and use a small servo arm.
To prime the engine, the choke butterfly valve must be completely shut and must not
catch on the intake ram tube. This means that the intake ram tube must be exactly
centred onto the carburettor. Shut the choke butterfly valve, mount the intake ram
tube and tighten the two fixing screws. If you now cannot open the choke butterfly
valve, you know that you have to readjust and try again.
Carburettor settings
The high and low speed needle valves have the letters H=high speed, L=low speed
marked on the carburettor body adjacent to the respective needles.
With intake ram tube and intake manifold
The large nickel plated screw for the throttle lever stop is useful for the test stand, but
when the throttle is operated by a servo this screw should be removed.
The adjustment of the high speed needle is very much influenced by the size of the
propeller, as well as by the use of an intake ram tube. If the engine is run as supplied
with no intake ram tube and using a big prop, it may be necessary to set the high speed
needle at up to 2 1/2 turns open.
Although the low speed needle setting will not differ much from 1 1/4 turns, it must be
carefully adjusted, especially if you don't want to use an intake ram tube, as for a reliable
low speed idle the needle must be on the lean side, but for a good throttle response
the needle must be on the rich side. But it is not difficult to find a compromise setting
whereby idle and acceleration is satisfactory. The acceleration will be greatly improved
by an intake ram tube! It is advisable to have a standard servo for the throttle, do not
use a high speed servo. Should you run the engine on the test rig, operate the throt-
tle lever at the same speed as a servo, in other words do not slam open the throttle.
If you decide to fit the cast aluminium intake manifold or make one from a copper
bend and use an intake ram tube so as to take the intake air from the fuselage, the high
speed needle then needs only 3/4 of a turn open. A full turn open and the engine will
©2012 Toni Clark practical scale GmbH Zeiss-Str.10 D-32312 Lübbecke Tel. 0049 5741/5035 Fax. 05741/40338 www.toni-clark.com
Instructions Titan ZG 45PCI-HV
Standard needle valve settings
Without intake ram tube
With intake ram tube
H
L
1 1/2
1 1/4
1
1 1/4
3/4
1 1/4
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