hroussard
05-22-2005, 08:23 PM
I have a 1975 B24R Sierra . Several weeks a ao, I had
to abort a flight because the engine started to run
really rough and the oil temps when up almost to the
red. Turns out that the top plug in nr 3 ( aft
passenger side) had a broken insulator which obviously
made the engine run rough. That is the background ( or
maybe that's the beginnning ) here is the story.
I went flying yesterday and after about 20 minutes ,
at about 3,500 ft, the engine "hick-upped" lost about
25 revs for a second or so and then ran fine for a few
minutes. Than, the engine started to gradually run
rough again, not too bad at first. I happen to be
flying with a very seasoned flight isntructor who also
own a sizable aircraft maintenance shop so we were
able to keep all the gauges in sight and we were able
to relate to each other what we saw, heard and felt. I
noticed that suddenly that the gauge showing rich /
lean status, which was pegged at 100 degrees rich of
peak, swung up to pretty well to the red line which is
where the temperature shows effective totally leaned
out. I than increased mixture control and enriched the
mixture to bring the needle back down to 100 degrees
rich of peak. The engine kept running rough, we
increased trottle ( maximum revs) and reduced manifold
pressure to reduce load on the engine and returned to
base. Oil temp stayed a little higher but we were
descending at higher airspeed so that would
potentially not mean anything. Back on the ground the
engine ran smooth at idle.
We also checked magneto's in the air ( I have an
Horizon P 1000) and they worked perfectly , mag drop
about 20 revs on both left and right magneto.
I also noticed before the flight ( on the ground
immediately after starting the engine) that there was
a slightly "harder" metallic knocking sound for a few
minutes at the max.
So , input please. What do you suggest it might be?
Valve?? cylinder? I believe that the fuel injection
system is working fine but I am not sure because I do
not have an engine analyzer installed. My mechanic
will start looking at the a/c tomorrow and any input
would be appreciated.
Thanks
HarryR
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to abort a flight because the engine started to run
really rough and the oil temps when up almost to the
red. Turns out that the top plug in nr 3 ( aft
passenger side) had a broken insulator which obviously
made the engine run rough. That is the background ( or
maybe that's the beginnning ) here is the story.
I went flying yesterday and after about 20 minutes ,
at about 3,500 ft, the engine "hick-upped" lost about
25 revs for a second or so and then ran fine for a few
minutes. Than, the engine started to gradually run
rough again, not too bad at first. I happen to be
flying with a very seasoned flight isntructor who also
own a sizable aircraft maintenance shop so we were
able to keep all the gauges in sight and we were able
to relate to each other what we saw, heard and felt. I
noticed that suddenly that the gauge showing rich /
lean status, which was pegged at 100 degrees rich of
peak, swung up to pretty well to the red line which is
where the temperature shows effective totally leaned
out. I than increased mixture control and enriched the
mixture to bring the needle back down to 100 degrees
rich of peak. The engine kept running rough, we
increased trottle ( maximum revs) and reduced manifold
pressure to reduce load on the engine and returned to
base. Oil temp stayed a little higher but we were
descending at higher airspeed so that would
potentially not mean anything. Back on the ground the
engine ran smooth at idle.
We also checked magneto's in the air ( I have an
Horizon P 1000) and they worked perfectly , mag drop
about 20 revs on both left and right magneto.
I also noticed before the flight ( on the ground
immediately after starting the engine) that there was
a slightly "harder" metallic knocking sound for a few
minutes at the max.
So , input please. What do you suggest it might be?
Valve?? cylinder? I believe that the fuel injection
system is working fine but I am not sure because I do
not have an engine analyzer installed. My mechanic
will start looking at the a/c tomorrow and any input
would be appreciated.
Thanks
HarryR
Yahoo! Mail
Stay connected, organized, and protected. Take the tour:
http://tour.mail.yahoo.com/mailtour.html
------------------------ Yahoo! Groups Sponsor --------------------~-->
In low income neighborhoods, 84% do not own computers.
At Network for Good, help bridge the Digital Divide!
http://us.click.yahoo.com/B9pRWD/3MnJAA/Y3ZIAA/SyTolB/TM
--------------------------------------------------------------------~->
Join BAC today and be a part of the ONLY Type Club for the Musketeer series!
www.beechaeroclub.org
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/musketeermail/
<*> To unsubscribe from this group, send an email to:
musketeermail-unsubscribe@yahoogroups.com
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/