User Manual

Introduction

Congratulations on purchasing a Saito 4-cycle control line engine. These engines have

been equipped with a newly designed control line carburetor/venturi system to ensure

efficient and reliable performance of control line model aircraft.

For the basics of engine specifications, safety issues, warranty information, break-in/

operation and a complete parts listing of the engine, please refer to the basic “Small-

Medium Single Cylinder 4-Stroke Engine Instructions” packaged with the engine.

Fuel: We suggest a fuel containing 20–22% synthetic oil and 10–15% nitro-methane.

Use of fuels composed entirely of castor oil is not recommended, however, a mix of

synthetic/castor oil is acceptable.

Propeller: The following bench mark propellers are provided as a point of reference.

Specific propeller values will depend on many variables. The main concern is to not

run the engine lean nor to exceed 10,000 rpm during the break-in process (see complete

break-in information below). The use of a tachometer during engine operation and

break-in is highly recommended.

FA-56CL APC 12X6 @ 9,000 with stock venturi; 9,700 rpm with small venturi insert

FA-62ACL APC 13X6 @ 9,100 with stock venturi; 9,700 rpm with small venturi insert

FA-72CL APC 14x6 @ 8,400 with stock venturi; 9,000 rpm with small venturi insert

Removal/Installation of the Small Venturi (82-1-9)

Tests have shown that the use of the larger venturi bore will increase the engine rpm’s by about 600

to 700 rpm. The engine comes with the small venturi installed. If you wish to remove the small venturi

please refer to the following photos and steps.

We suggest you make a small mark with a

marker on the side of the removeable venturi

body (82-1-5) and carburetor body (82-1-1)

as shown in the photo to the right. This will

help you line the venturi body up again when

you reinstall it in the carburetor body.

Part numbers given as reference and found

on exploded view on page 4 of this addendum.

Using a 1.5mm allen driver, loosen the venturi

body guide screw (82-1-7) so the venturi body

can be removed.

Using your fingers on the handle on the side

of the venturi body, remove the venturi body

from the carburetor body.

Use the 1.5mm driver to push the small venturi

insert (82-1-9) and remove it. Keep it in a safe

place in the event you wish to reinstall it.