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Hello
I have been away for a while but back now.
I drained the sump on the Cam Cover and there was about a cup of oil.
There is a large plug on the side of the fuel pump and I assumed that this
is the level the oil is supposed to be that is mentioned in the manual. I
filled the fuel pump to this level and it took about =C2=BC cup or +/- 60ml
When I tried to start the engine there is now nothing, not even a =9C
poof=9D or even one firing on the primer fuel. I tested for spark an
d that seems to be OK, and I can hear the Slickstart buzzing when I power i
t up
I removed all the plugs and fuel injector nozzles, I fitted a nut to one of
the nozzles and rotated the prop by hand, I got one squirt of gas out of t
he nozzle but after that I only saw drops forming at the tip of the nozzle.
Is the return oil line that runs from the fuel pump to the sump equipped wi
th a one way valve? I thought of running oil into the fuel pump and then ch
ecking if oil runs out of the sump plug cam case plug. Not sure if there is
a direct connection, but there must be something that stops the cam case o
il draining into the fuel pump.
The deposits at the rear of the exhaust manifold is darkish gray
Would appreciate you suggestions.
Thanks
Mike
From: owner-lom-list-server@matronics.com <owner-lom-list-server@matronics.
com> On Behalf Of sjbeaver
Sent: August 24, 2020 5:08 AM
Subject: Re: Lom-List: Fuel Mixture
That is a surprising amount of oil. In a normally functioning, current revi
sion engine I would expect to see perhaps a table spoon of oil. In the olde
r style pump with a filler port on the side, perhaps a cup. Then again I ha
ve never left the pump open overnight. There is a connection from the engin
e oil system to the pump in that one of the factors the pump uses to set th
e fuel mixture is oil pressure.
I would suggest proceeding as follows:
1. Remove the drain plug/screen under the scavenge pump. How muc
h oil do you see there? If you see a a cup or more then I would suggest all
is well. If you see almost none then it would appear that the cam case oil
is somehow leaking into the injection pump. This seems unlikely though
2. Put everything back together and run the engine. Asses the pe
rformance per my previous email and then remove the oil drain plug in the p
ump again. How much oil this time? (Use something more scientific than the
hangar floor to measure it :) )
Steve
--
Stephen Beaver
Tel: 614-937 4189
On Aug 24, 2020, at 12:04 AM, <mike@vision499.com <mailto:mike@vision499.co
m> > <mike@vision499.com <mailto:mike@vision499.com> > wrote:
Hello Steve
I also thought it was impossible, I drained it from a small plug at the bot
tom of the fuel pump, the plug only needs a 12mm wrench so is small. Workin
g forward from the rear of the pump there is a small slotted screw and then
the plug. These are the only fittings on the bottom of the fuel pump. I ca
n see a large nut on the camshaft cover that I assumed to be the drain unde
r the scavenge pump, I did not open that. Could this oil have siphoned from
somewhere?
Thanks for you help
Mike
From: owner-lom-list-server@matronics.com <mailto:owner-lom-list-server@mat
ronics.com> <owner-lom-list-server@matronics.com <mailto:owner-lom-list-se
rver@matronics.com> > On Behalf Of sjbeaver
Sent: August 23, 2020 7:57 PM
Subject: Re: Lom-List: Fuel Mixture
Three pints seems impossible. Did you drain that from the pump, or from the
screen at the rear of the camshaft housing?
Steve
--
Stephen Beaver
Tel: 614-937 4189
On Aug 23, 2020, at 10:33 PM, <mike@vision499.com <mailto:mike@vision499.co
m> > <mike@vision499.com <mailto:mike@vision499.com> > wrote:
Hello Steve,
I drained the oil from the fuel pump. I removed the plug and oil came out v
ery slowly so I left it overnight. Fortunately I put a small container unde
r the drain hole as this morning I found that about 3 pints had drained out
=2E
I cannot imagine where there is room for that amount of oil. Could it be th
at my scavenge pump is not doing it=99s job?
Have not tried to start it again but will let you know
Thanks
Mike
From: <mailto:owner-lom-list-server@matronics.com> owner-lom-list-server@m
atronics.com < <mailto:owner-lom-list-server@matronics.com> owner-lom-list-
server@matronics.com> On Behalf Of sjbeaver
Sent: August 18, 2020 10:00 AM
nics.com>
Subject: Re: Lom-List: Fuel Mixture
Mike.
There are no o-rings in the fuel inject system to be concerned about and I
would suggest that you do not disassemble it. It is a complex and very prec
ise device! - What you might do, however, is remove the drain plug on the u
nderside of the unit and allow any accumulated oil to drain out. If sitting
for a long time excess oil can accumulate in the pump and interfere with t
he mixture.
Let me run through some of the other items you might check. I am not implyi
ng that there is any part of the manual you have not digested. Just making
sure I don't omit anything :)
First and foremost (If I had a $ for every time I explain this . . . ) is
the automatic mixture system. People used to operating American engines see
m to think that the engine should always be operated at the most rich setti
ng available. That is just not the case with the LOM and doing so so will h
ave serval rather bad consequences.
Look closely at the mixture control arm that extends from the side of the f
uel injection pump. There is a slot in the arm, inside of which is a small
pointer. Also on the side of the pump is a shiny metal plate shaped like a
pizza slice on which are marked the mixture settings. Something like +3, +2
, +1, N, -1, -2 with the -2 being nearest the top. Adjust your mixture cont
rol mechanism so that the "normal" (all phases of operation below 10,000')
corresponds to the pointer being aligned with the 'N' mark. - Actually 'N'
inside a circle. Now you know the mixture is set exactly as it should be. A
gain - do not operate the engine at the full rich setting. Doing so will di
sable the automatic mixture system, foul the plugs, wash lubricant from the
cylinder walls and other bad things.
Next, start the engine and let it warm up for an extended period. When the
oil temp is up in the 100F area, carefully and with the appropriate precaut
ions run the engine at full power (super charger engaged) Switch from both
to magneto 1. What RPM drop do you see? Go back to both, then magneto 2. Ag
ain, what RPM drop do you see? I would expect a drop in the 25-35 RPM area.
Anything other than that suggests your ignition timing is a little out. It
is a simple matter to loosen the magneto clamps and rotate the mags a litt
le until the 25-35 RPM drop is observed. Why not just time the mags with a
buzz box in the traditional manner? For two reasons: 1) This is how the man
ual says to do it and 2) these magnetos have automatic advance and retard s
ystems so static timing means almost nothing.
How that the mixture and the ignition timing are up to snuff, you can do so
me testing. Operate the engine for as long as is reasonable at a cruise sor
t of power setting. Say 25" of manifold pressure. (It doesn't matter if the
super charger is engaged or not). Now shut down and observe the exhaust pi
pes. Are they back and sooty, a very light gray (almost white) or a nice mi
d gray, the color of a slate roof? - We want the slate color.
If in doubt, remove the spark plugs and see what they look like.
Another useful trick (if you have straight pipes) is to run the engine in t
he dark and look into the exhaust pipes of the running engine. At medium po
wer settings look for a nice blue flame tinged with yellow to indicate the
ideal running conditions.
Finally, since I see you are in BC, you could contact Pavol Novak who now r
esides at Qualcom Beach on Victoria Island. He is a Czech LOM factory train
ed technician and expert on the engines (and Zlin airframes)
Steve
--
Stephen Beaver
Tel: 614-937 4189
On Aug 18, 2020, at 12:14 PM, <mike@vision499.com <mailto:mike@vision499.co
m> > <mike@vision499.com <mailto:mike@vision499.com> > wrote:
I have the 4 cylinder engine with supercharger, fuel injection and automati
c mixture control. The motor was factory reconditioned in 2003 and has had
Zero hours since
I started the motor recently and there are loud =9Cpops=9D out
of the exhaust. An AME on the field thought that it was running lean.
Fuel pressure is good
I see that I can adjust the mixture at the fuel pump but want to ask if the
re is something else I should check for first.
Has anybody opened the fuel pump, are there any seals that would have deter
iorated. From the drawing I cannot see if there are any seals that may need
replacing.
Thanks
Mike
Mike Pienaar
m <mailto:ike@vision499.com> ike@vision499.com
Home: +1 250-999-8121
Mike cell: +1 250-885-0554
1-1100 Tulip Ave, Victoria, BC, V8Z 0A2
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