All,
Earlier this week, there was an interesting posting re. carb banjos and fuel
hose proximity to hot exhaust pipes.
I quote part of it:
>I went to see another builder yesterday, Peter Field in Windlesham. He has
>just hung his 912S. I took the opportunity to look at his carb banjos. They
>both pointed forward towards the exhaust manifold. And they were sealed to
>discourage changing their position.
>
>I therefore repeat my suggestion that the factory should be told and
>discouraged from doing this !
As there are other important attachments on the engine that are NOT
sealed/marked with red paint, I called an authorized Scandinavian Rotax
dealer/repair facility for an explanation and comments:
The red coloured seal is put on the banjos at the factory for two reasons:
- To show the factory quality inspector that the fitting has been installed
with the correct torque (the torque wrench squirts the paint on
automatically)
- To give some locking effect, and - more importantly - enable easy visual
detection during regular intervals if anything has moved, meaning loss of
torque.
It is OK to rotate the banjo to suit the desired fuel hose routing. This
requires of course that the bolt must be released and subsequently tightened
to the correct torque (ref. Rotax manual), BUT: The copper sealing washers
MUST be replaced by new, unused ones. Copper does not spring back when
pressure is taken off, and will seal properly only on the FIRST tightening.
The washers are standard soft copper washers that can be bought at hardware
stores, need not be original Rotax parts but check for correct thickness in
new condition (not measured off the used ones) in the Rotax manual.
Industrial type locking liquid can be used on the assembled parts (only on
the outside) but is not essential. Just simply mark the joined parts with a
line drawn with permanent marker pen for the regular visual inspections, to
detect whether anything has moved.
Regards,
Svein
A225 - XS trigear - now in Norway
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