Today's Message Index:
----------------------
1. 04:52 AM - Re: loss of compression (Catz631@aol.com)
2. 05:04 AM - Re: Re: loss of compression (Catz631@aol.com)
3. 05:49 AM - Re: Re: loss of compression (Dave Austin)
4. 10:43 AM - Re: loss of compression (rparigor@suffolk.lib.ny.us)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: loss of compression |
Roger,
If I pull back on my throttle all the way on the ground it will go back to
about 1400 rpm. This equates to a minimum of aprox 1800 in the air due to
the airflow. I have it set this way so that I can slow down and land the
airplane. Previously I had it set higher and it was difficult to get the
aircraft slow enough and out of ground effect. I don't allow the engine to idle
at
1400. 1800 is my minimum. I use a Vernier throttle to control it The only
time I was using 1400 was at engine shutdown at the end of a flight (and that
was on the recommendation of one of the 4 Rotax distributors in the country)
I am aware of the damage that can occur to the gearbox with continued low
rpm settings. I saw the results on some gearbox parts at my Rotax class (many
years ago). The 1400 shutdown is for a very short time in an effort to stop
the" kick back". (but I will use the higher rpm method and higher octane
fuel)
My carbs are in sync. I did that about 8 hrs ago BUT I did not check the
float heights. I will give that a shot!
Thanks again for your tips!
Dick Maddux
Rotax 912 UL
Milton,Fl
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: loss of compression |
Dave,
If your oil tank is high (which mine is) then the oil will tend to siphon
into the crankcase when you shutdown the engine. They mentioned that in my
Lockwood Rotax class which I attended years ago.( and in Kitfox bulletins)
The location is the only place to mount the oil tank on the early Kitfoxes so
I have to live with it.(changed on the newer airplanes)
The lines are full of oil so the hot oil just starts a small reverse flow.
It takes awhile for a lot of oil to drain into the crankcase but that is
the reason you turn the prop thru before you fly the aircraft. You are moving
this oil out of the crankcase back into the oil tank.( also to check the
actual oil level)
Dick Maddux
Rotax 912 UL
Milton,Fl
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: loss of compression |
Hi Dick,
My oil tank is just above the dry sump. Maybe that's why I don't get
the syphoning.
Maybe a check valve is the answer to your situation. How many turns of
the prop does it take to get the oil back into the tank?
Dave Austin 601HDS - 912
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: loss of compression |
Hi Dick
Not flying my 914 yet but a few ideas on shut down
kickback.
*I have heard that when you get ignition modules hot,
the first thing that happens is that when you ground them, they may not
shut down, or partially shut down. Just for hahas before a very hot shut
down at 1400 RPM give a mag check and see if you get any coughing on one
or both mags.
*On a hot engine there could be glowing carbon that
could give a firing when you don't want one. I had a 1972 yamaha
RT-2 360 thatI removed spark plug on a hot engine and proceeded to
take a compression test, got a firing and trashed my gauge! You could try
pulling choke for 15 seconds before and during shut down??
*Did you
adjust low speed mixture? You may want to adjust them on a very hot engine
on a very hot day, or do as manual says find highest RPM and instead of
richening (I think it is 1/2 turn, please check manual) go a slight bit
richer.
Ron Parigoris
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|