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MVVS 45 - excessive oil resuide

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Old 09-17-2006, 02:31 PM
  #1  
abrous
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Default MVVS 45 - excessive oil resuide

Hi,

I got my 45IRS/MG since last February. It should have ran at least 20 liters since now.
I am using Mobil 1 2T 40:1 (25ml oil / liter). I am now running a Krumsheid canister
(I used a Bisson before). My prop is Menz 22x8. The engine operates smoothly with
7150 RPM at top end.
The problem is the excess black resuide on the plane after few flights.
Pe told me in the past that this is perfectly normal and will dissapear as engine breaks in.
I am attaching a photo to show what I mean.
After four 8 minute flights: The left aircraft has a DA50 with the same running hours.
The right is the one with the MVVS 45.
Do you think that this is normal? How long does it take to have the 45 broken in ??
I still can't see any signs that the oil amount is reduced.
Have I done something wrong ? The second photo is a closeup of the plug.
What do you think ?
I have set the H needle approximately in the middle between RPM drop cause of lean top end and RPM drop
cause rich top end as Walbro manual notes.
My low end is good and leanning the L needle more destabilizes the idle.

ALSO - I noticed some "sprayed" black oil in the front of my YAK's cowl. It is sprayed from the front ball bearing. Is it normal
for the front ball bearing to leak a little ?

Cleaning the aircraft after a flying day is a real chalenge. In my opinion this is the only weak point of this great engine.

Regards,

Angelo



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Old 09-17-2006, 05:24 PM
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Default RE: MVVS 45 - excessive oil resuide

The plug is black which indicates too rich running. It should look like this:


The front bearing loosing oil may be a problem with overheating. How do you cool your engine?
The Jak's large cowl normally has way too much air entrance with too little air exit, and all air goes by the engine without any cooling work done.
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Old 09-18-2006, 01:37 AM
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Default RE: MVVS 45 - excessive oil resuide

Thanks for the reply Pe,

It seems to me that I can't lean the L needle any more because the idle becomes unstable. Is it possible to foul the plug cause of rich top end ?
Is the damage in the front bearing permanent ?

Regards,

Angelo
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Old 09-21-2006, 10:10 AM
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Default RE: MVVS 45 - excessive oil resuide

abrous

Have you leaned out the engine? and has it made any difference? I wonder if the black gung is a product of the supplied oil?

I have the 45MG and its improving with every tank of fuel that goes through it, still running in on a 22x10 prop can't wait for the supplied oil to run out so I can give it its head on a 20x10 or similar.

Mike
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Old 09-21-2006, 06:05 PM
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Default RE: MVVS 45 - excessive oil resuide

My 58 Pro has 1 1/2 gals thru it now and the exhaust residue is getting cleaner
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Old 09-22-2006, 01:45 AM
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abrous
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Default RE: MVVS 45 - excessive oil resuide

Hi,

As I said before I already tried to lean the L needle and the idle becomes unstable giving me the impression of lean low end (Throttling down
from full throttle the engine stays at high idle for 5 -10 seconds or more). I just wondering if it is possible to have all this mess because of rich
H needle. I tunned the H with the following procedure : At full RPM I leaned the H until RPM droped. Next I riched H until again RPM droped cause
of rich top end . I set the needle in the middle between the two poins. I turned to Castrol TTS from Mobil 1 today. I'll give it a try this weekend.
Any thoughts ?


Angelo
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Old 09-22-2006, 07:12 AM
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Default RE: MVVS 45 - excessive oil resuide

Abrous,
set the high needle for stable rpm, not for rpm-drop. If the needle is set ok, then rpm will slowly rise to best rpm, without dropping again. (providing your engine is cooled)
If you get immediate best rpm, and then an rpm drop, the H needle is too lean.
If the transfer from high idle to full throttle is hesitating, the low needle is too lean.

With a plug black like yours, the ignition will start to cut out sooner or later, so fit a new plug first.

Going to Castrol TTS even more needs to have the cooling OK, because the oil is thinner than, and inferior to the Mobil. In a Yak, you MUST HAVE a baffled cowl and air guiding plates, as well as good air extraction from the cowl.
this is very important. For a minimum application, look at the QQ Yak, who also has a like system installed, though it can be done much better.
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