Skybound Star-Tuner

Description

Skybound Star-Tuner

Here goes: You are about to fit the low jet setting device. Before you get started, let’s familiarise
ourselves with some of its features while you have it in front of you.

Orange Part
At the top and bottom of the orange part are ‘line features’ that indicate the direction of the blade
when inserted in the low jet slot. These features make fitting to the carburettor easier when the
view is limited.

The vertical grip detail around the part’s circumference creates peaks and troughs. Peak to peak or
trough to trough equals 2 minutes of travel (as on a clock face), and 1 minute of travel is peak to
trough, and vice versa.

Black Star Part
It is made up of four cardinal pointers (15 minutes apart). One of the cardinal points has a round
pocketed hole that sits over and grips the high jet, holding the device in place and acting as an
anchor to prevent the part from rotating. This allows the cardinals to serve as the datum when the
orange part is rotated through its turn minutes.

Lanyard
A bungee cord with a looped end. Use a feature (fuel line or throttle cable) to wrap the bungee
around and pass the Star-Tuner through the loop before fitting it to the carburettor. Ensure the
bungee is free to move and not under tension.

Fitting
Secure the bungee and fit the device by partially offering up the round, pocketed hole on the black
star over the high jet long post. Use the line features on the orange part to align with the slot on the
low jet screw. Gently push the part on until the low jet screw head is completely inserted and out of
sight inside the brass tube. If there is any resistance to fully inserting it into the slot, you may find
the low jet slot has previous damage from screwdriver use, and the jet may need attention or
replacement. Be careful not to rotate or disturb the current low-jet setting. The Star-Tuner is
designed to stay fitted to the carburettor. Use a Pozi No.1 screwdriver to tighten the small screw.

Setting
Now that it’s fitted, we need a reference point to capture the current setting and determine the
current state of tune. Use only a pencil (pencil marks can be washed off with soap and water if
needed) and mark the length of a peak or trough that aligns with one of the visible, accessible
black cardinal points (normally the one nearest the propeller). You now have your current setting as
a reference point, which you can refer back to if needed. Gently turn the orange part clockwise
until it stops. Do not use force past this point, as it will damage the jet seat and the Tuning Tool.
Count back from the pencil mark to the cardinal point to capture the current state of tune for future
reference.

If your carburettor is an unknown, recently rebuilt, or if you are starting again, gently close the low
jet by turning the orange part clockwise until it stops. Then, mark the length of a peak or trough that
aligns with one of the visible and accessible cardinal points. Count backwards (anticlockwise) from
this point by the desired number of minutes and mark with a pencil line. Turn the low jet
anti-clockwise to the factory-recommended number of minutes. For example, the Moster Plus is 15
minutes from closed (one cardinal point to the next).

Removing
The Star-Tuner is designed to stay fitted to the carburettor, and it is not advised to remove it
repeatedly, as this can damage the tool. If you want to remove the Tuning Tool, do not apply a
sideload force perpendicular to the blade direction, as this can damage the blade and render the
tool useless. Any gentle wiggling should be along the blade only (use the line feature on the
orange part to assess theblade direction). We suggest removing every year or 150 hours for
cleaning and general inspection. Replace if you have any concerns.

Fault Finding

If you experience difficulty starting the engine, or if the carburettor requires constant priming to run
when cold, or if it hesitates or bogs down when gently applying power from tick-over when warm, or
dies when bending over to pick up risers for the ground, then turn the Star-Turner anti-clockwise
(richer mix) by 1 minute at a time until the problem is resolved. If you have applied for more than 5
minutes in any direction, a different underlying problem may exist and will need to be investigated.
The low jet constantly contributes to fuel delivery even when the high jet circuit comes into play;
this is why tuning the low jet is an essential part of the process and is made easier with the
Star-Tuner installed.

Wrapping Up
We hope you find the Star-Tuner a beneficial addition to your engine upkeep and overall flying
experience. It should give you the confidence to make minor adjustments on the go, knowing you
have a point of reference to revert to if needed.