Lom-List Digest Archive

Sat 09/12/20


Total Messages Posted: 1



Today's Message Index:
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     1. 09:16 PM - Re: Fuel Mixture (mike Pienaar)
 
 
 


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    Time: 09:16:51 PM PST US
    From: mike Pienaar <mikepienaar09@gmail.com>
    Subject: Re: Fuel Mixture
    Thanks again for your help, got my engine started and will check oil level in fuel pump again when I have run it again. I cannot visualise what the oil does in the fuel pump. I have model 5151.03 and the manual mentions oil in through pressure reducing valve (29) with the level controlled by a drain hole (31) and out to the scavenge pump (32) You say "The pump is just sensing oil pressure" May I ask you to explain again. If it is not too much trouble is there a convenient time for us to chat on the phone? Thanks again and keep well Mike On Thu, Sep 10, 2020 at 1:19 PM sjbeaver <sjbeaver@gmail.com> wrote: > The method to check ignition timing is pretty simple. Run the engine at > maximum RPM and test each mag. You should see a drop of 25 RPM. If not, > adjust the mags as necessary to get that. Advancing the timing will give a > smaller drop, retarding it a larger one (I think) > > There can be no "one-way valve" because no oil actually flows anywhere. > The pump is just sensing oil pressure. > > Steve > -- > Stephen Beaver > Tel: 614-937 4189 > > > On Sep 7, 2020, at 6:00 PM, mike@vision499.com wrote: > > Thank you very much, I think it was flooded and then I took the spark > plugs out and blew compressed air through the plug holes. When I tried > again I might have been wary of flooding it again and did not prime enoug h. > Will try again to-morrow. > > Is there an easy way to check ignition timing? > > When I mentioned the "return oil line from the fuel pump" I was referring > to the oil passages that I presume run through the mounting flange betwee n > the fuel pump and the cam shaft sump. One to supply oil and one to drain. > > Will let you know what happens to-morrow > > Thanks again > > Mike > > *From:* owner-lom-list-server@matronics.com < > owner-lom-list-server@matronics.com> *On Behalf Of *sjbeaver > *Sent:* September 7, 2020 12:39 PM > *To:* lom-list@matronics.com > *Subject:* Re: Lom-List: Fuel Mixture > > Mike, > > Those are interesting results! You appear to have the older style pump an d > you are correct that it should be serviced with engine oil up to the leve l > of the filler plugs. > > If there is a spark (at about the correct time) and the primer is > delivering fuel then it is hard to understand why it didn't fire to some > extent. Could it have been flooded? Inverted engines are rather prone to > flooding. You can try clearing the engine out by propping it backwards, b ut > waiting for 20 minutes and trying again with the throttle about half way > open is usually best. > > I am confused by your reference to the "return oil line from the fuel > pump". There should be three connections to the pump: fuel inlet, fuel > return and fuel pressure. Older pumps may also have a hose nipple on the > side to vent the oil system. This is usually connected to small hose > running upwards above the level of the and is open at the top. > > Steve > -- > Stephen Beaver > Tel: 614-937 4189 > > > On Sep 6, 2020, at 7:28 PM, mike@vision499.com wrote: > > 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 thi s > 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 +/- 60 ml > > When I tried to start the engine there is now nothing, not even a =9Cpoof=9D > or even one firing on the primer fuel. I tested for spark and that seems > to be OK, and I can hear the Slickstart buzzing when I power it 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 > the nozzle but after that I only saw drops forming at the tip of the nozz le. > > Is the return oil line that runs from the fuel pump to the sump equipped > with a one way valve? I thought of running oil into the fuel pump and the n > checking if oil runs out of the sump plug cam case plug. Not sure if ther e > is a direct connection, but there must be something that stops the cam ca se > oil 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 > *To:* lom-list@matronics.com > *Subject:* Re: Lom-List: Fuel Mixture > > That is a surprising amount of oil. In a normally functioning, current > revision engine I would expect to see perhaps a table spoon of oil. In th e > older style pump with a filler port on the side, perhaps a cup. Then agai n > I have never left the pump open overnight. There is a connection from the > engine oil system to the pump in that one of the factors the pump uses to > set the fuel mixture is oil pressure. > > I would suggest proceeding as follows: > > 1. Remove the drain plug/screen under the scavenge pump. How > much oil do you see there? If you see a a cup or more then I would sugges t > all is well. If you see almost none then it would appear that the cam cas e > oil is somehow leaking into the injection pump. This seems unlikely thoug h > > 2. Put everything back together and run the engine. Asses the > performance per my previous email and then remove the oil drain plug in t he > pump again. How much oil this time? (Use something more scientific than t he > hangar floor to measure it :) ) > > Steve > -- > Stephen Beaver > Tel: 614-937 4189 > > > On Aug 24, 2020, at 12:04 AM, <mike@vision499.com> <mike@vision499.com> > wrote: > > Hello Steve > > I also thought it was impossible, I drained it from a small plug at the > bottom of the fuel pump, the plug only needs a 12mm wrench so is small. > Working 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 can see a large nut on the camshaft cover that I assumed to be th e > drain under 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 < > owner-lom-list-server@matronics.com> *On Behalf Of *sjbeaver > *Sent:* August 23, 2020 7:57 PM > *To:* lom-list@matronics.com > *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> <mike@vision499.com> > wrote: > > Hello Steve, > > I drained the oil from the fuel pump. I removed the plug and oil came out > very slowly so I left it overnight. Fortunately I put a small container > under the drain hole as this morning I found that about 3 pints had drain ed > out. > > I cannot imagine where there is room for that amount of oil. Could it be > that my scavenge pump is not doing it=99s job? > > Have not tried to start it again but will let you know > > Thanks > > Mike > > *From:* owner-lom-list-server@matronics.com < > owner-lom-list-server@matronics.com> *On Behalf Of *sjbeaver > *Sent:* August 18, 2020 10:00 AM > *To:* Lom-List Digest Server <lom-list@matronics.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 > precise device! - What you might do, however, is remove the drain plug on > the underside 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 interfe re > with the mixture. > > Let me run through some of the other items you might check. I am not > implying 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 . . . ) i s > the automatic mixture system. People used to operating American engines > seem to think that the engine should always be operated at the most rich > setting available. That is just not the case with the LOM and doing so so > will have serval rather bad consequences. > > Look closely at the mixture control arm that extends from the side of the > fuel injection pump. There is a slot in the arm, inside of which is a sma ll > 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 > control 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. Again - do not operate the engine at the full rich setting. > Doing so will disable 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 th e > oil temp is up in the 100F area, carefully and with the appropriate > precautions 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. Again, 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 little 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 manual says to do it and 2) these magnetos have automatic > advance and retard systems so static timing means almost nothing. > > How that the mixture and the ignition timing are up to snuff, you can do > some testing. Operate the engine for as long as is reasonable at a cruise > sort of power setting. Say 25" of manifold pressure. (It doesn't matter i f > the super charger is engaged or not). Now shut down and observe the exhau st > pipes. Are they back and sooty, a very light gray (almost white) or a nic e > mid 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 > the dark and look into the exhaust pipes of the running engine. At medium > power 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 > resides at Qualcom Beach on Victoria Island. He is a Czech LOM factory > trained 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> <mike@vision499.com> > wrote: > > I have the 4 cylinder engine with supercharger, fuel injection and > automatic mixture control. The motor was factory reconditioned in 2003 an d > has had > Zero hours since > > I started the motor recently and there are loud =9Cpops=9D ou t 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 > there is something else I should check for first. > > Has anybody opened the fuel pump, are there any seals that would have > deteriorated. From the drawing I cannot see if there are any seals that m ay > need replacing. > > Thanks > > Mike > > Mike Pienaar > *m*ike@vision499.com > *Home: +1 250-999-8121* > Mike cell: +1 250-885-0554 > 1-1100 Tulip Ave, Victoria, BC, V8Z 0A2 > > > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm _campaign=sig-email&utm_content=emailclient> > Virus-free. www.avast.com > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm _campaign=sig-email&utm_content=emailclient> > > > <OIL-DRAIN.JPG> > >




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