Bud,
I don't think you received my commentary on the nitrile gaskets. =46rom
a previous e-mailing:
FWIW, the nitrile gaskets are probably OK if you have the carb off and
are doing a rebuild. Where you can turn the carb upside down to put the
gasket in place and properly fit the bowl to the carb body without
disturbing the gasket. Otherwise they are too floppy to try and install
on the bottom in an upright carb, in amongst the exhaust manifold and
various plumbing on the aircraft. I was very careful, checked them with
a mirror for location and fit, still they moved out of position while
getting the bowls back on and tight. Ended up with both gaskets cut by
the bowl.
Also, my float bowl nut uses an O-ring and not a flat gasket. The
torque is 4 ft-lbs.
Blue skies & tailwinds,
Bob Borger
Europa XS Tri, Rotax 914, Airmaster C/S Prop.
Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
3705 Lynchburg Dr.
Corinth, TX 76208-5331
Cel: 817-992-1117
rlborger@mac.com
On Jun 10, 2012, at 9:23 PM, Bud Yerly wrote:
=85< Snip >...
Bob Borger is suffering through a slightly different problem but close,
as does Homer Baker, and I have two 914s that had me pulling my hair out
with similar symptoms.
Here is a summary of what to check:
If the engine starts to die as the boost comes on, most likely the carb
float bowls are leaking.
Ed and I were pulling out our hair and are going to put in a product
deficiency report. I just did a bunch of work on a 914 because the carbs
had never been rebuilt over 300 hours. We put in a carb kit and it
worked great on the ground but at altitude were not able to get it to
perform as the engine began to sag and miss.
Final answer was to soak the paper float bowl gaskets overnight to get
them to swell and seal. Then you fly away and after the engine has set
a couple weeks, the gasket dries out and the leak reappears. Rotax now
uses a rubber gasket for the bottom of the bowl, which affects the
torque on the bolt on the bottom of the float bowl, and if memory serves
the torque is low at 48 inch pounds, and the rubber gasket, once
squished, gets some gas on it then it dries out and the bowls are loose
again after setting a bit. I don't mean to sound angry, just being
frank.
=85< Big Snip >...
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