OS 61SX-H tuning issue

[HeliJoel]

Hi,

A while back I restored two of my old Hirobo Eagles ( an 88 and 91 ). They both have OS 61SX-H engines one with an old Hatroi muffler and one with a Whispertech pipe. The OS with the Hatori runs as expected, two turns open on the main, 1/4 on the mid 2 out on the idle. The one with the Whispertech however is running way rich. 2 out on the idle, but closed on the mid range and about 1/2 turn out on the main. Flys fine there but anything more and it is too rich. I have check the carb for leaks and can't find an issue. Most other things I think about would cause unstable running and being too lean not rich.

Any thoughts?

Joel

[HeliJoel]

Hi,

So I did an experiment and took the WhisperTech pipe off and used another Hatori muffler. The engine now runs as expected, 2 turns out on idle, 1 turn out on the mid and about 2 turns out on the main. Makes me wonder why the WhisperTech needed so much less fuel ( I don't think it provided any more back pressure to the tank to require 1 1/2 less turns on the main ). Both run well with their respective settings, wonder if I should just fly the WhisperTech at a 1/2 a turn.

Joel