The Saito mufflers come in two types as shown above and below.

Some recent engines have a muffler type as shown to the left

It is usually better to mount the muffer in such a way that it points downward. Any excess fuel will then run out, not back into the cylinder.

The mufflers on Saito engines use 10mm (50,56 engines), 12mm (65, 80, 91, 100 engines), and 14mm (120, 150, 180 engines) thread sizes.

An alternative to the standard muffler is the flexible exhaust tube that is available in all three thread sizes. These are a little louder than the muffler, but not too noisy. Some versions have pressure taps.

Flexible exhaust pipes are available in three sizes.

10mm size (above) for 50,56 singles and 100 twin (thread size is M10x1.0)

12 mm size for 65, 72, 80, 91, 100 engines. A flex pipe exhaust without pressure tap is part number SAI65111A shown below.

A 12mm flexible exhaust pipe with a pressure tap is Saito part number 182TD-1112 (Horizon Hobbies part SAI182TD1112)

14mm size (see left and below) for 120, 150, 180 singles and 270,300 twins.

The flexible exhaust below (about 6 inches long) differs from the others shown above in that it has a threaded end on the outlet so that a conventional muffler may be screwed on.

Telemaster Trainer with Saito-65 This engine was purchased about 1989 and has the very old one-piece muffler that was sold with the Saito-50 and Saito-65 at that time

Saito-65 has Perry P-20 pump, fuel filter, OS Type-F plug, and APC 13x6 prop. Carb not adjusted for 10 years. Still runs great with 2000 idle rpm. Note old-style one-piece muffler.

A possible point of confusion: The optimistic English often refer to ‘mufflers’ as ‘silencers’.

The Saito-45S did not come with a real muffler. Just a short pipe with a pressure tap. (This engine is no longer sold in US; it is the same size and weight as the Saito-50 and Saito-56)