O.S. Engines 7DV Carb - 27181000 User Manual
Page 2

CARBURETTOR INSERT (for Type 7D only)
Two different sizes of carburettor insert are used with the Type
7D carburettor. A large I.D. insert is installed in the carburettor
fitted to the MAX-90FSR. A smaller I.D. one is installed in the
carburettor of the MAX-61 engine.
In the case of the MAX-90FSR, ordinary suction feed is suffici-
ent to use this carburettor with the large insert. If, however,
higher power output is required for aerobatic flying, it is permis-
sible to remove the insert. In this case, a muffler pressurised fuel
system should be used.
In the case of the MAX-61, a muffler pressurised fuel system
should be used on this carburettor with the smaller I.D. insert.
If higher output is required, it is permissible to replace this with
the larger insert, or to remove the insert completely, but, in
these instances, a pumped fuel supply, such as the Perry Pump
system, or Robart Super-Pumper should be employed.
* If higher output is required on the MAX-61 FSR or
MAX-61 VF engine equipped with the type 7DV
carburettor, use the optional Type 7D carburettor.
Mixture Control Screw
Idle Valve Set-screw
Idle Valve
Rotor
Carburettor Insert
(for Type 7D only)
HOW TO REMOVE THE CARBURETTOR INSERT
•Unscrew the rotor set screw and withdraw the throttle rotor.
•Remove the idle valve set-screw and carefully withdraw idle
valve.
• Extract the carburettor insert.
• Reassemble the carburettor.
SUBSEQUENT OPERATION AND CARE
Once the required settings, have been established it should be
unnecessary to alter them. Such slight needle valve alterations as
may be necessary to cope with differences in atmospheric condi-
tions or fuels, do not affect the other two adjustments. The
engine should start readily with the throttle in the idle position.
It is important that the carburettor operates under clean condi-
tions. Make sure that fuel is properly filtered before use. We
advise fitting a filter to your fuel can and another filter in the
delivery tube between tank and engine, to reduce the risk of the
carburettor jet becoming partially clogged and upsetting running
adjustments.
PARTS LIST
Description
Carburettor Complete
Needle Valve Assembly
Rotor Set-screw Assembly
Throttle Lever
Carburettor Retainer
Carburettor Insert-L (for 90)
Carburettor Insert-S (for 61)
Code No.
7D
29081000
29081934
27181600
26881406
29081719
29081210
29081239
7DV
27181000
29081934
27181600
26881406
29081719
The specifications is subject to alteration for improvement without notice.
6-15 3-chome Imagawa Higashisumiyoshi-ku
Osaka 546, Japan. TEL. Osaka (06) 702-0225
108207