Conference vmszoo::rc

    The high end needle is too lean. In the air, the engine will "unload"
    and turn higher RPM'S than on the ground. It get's hot and looses
    power. When it looses power (slows down) it cools off and then regains
    it's RPM'S.
    
    The low end mixture is either too lean or too rich. It depends on your
    symptoms. If, while at idle, the engine speeds up a bit just before it
    dies, it's too lean. On the other hand, if it gradually slows down
    (loads up) and then dies, it's too rich.
    
    When you try to go from idle to full throttle, if you get alot of smoke
    before it dies, it's loading up and is to rich. If it just cuts out,
    it's too lean. I suspect your low end is probably a little too rich.
    That's why your getting the hesitation in the air. The engine is
    loading up and takes a few seconds to clear itself.
    
    Try setting the high end needle to max rpm and then backing off 2 or
    three clicks. That should clear your leaning out problem in the air.

    ANYTIME you change the low end needle, ALWAYS go back and reset the
    high end needle. One affects the other.
    
    Steve

    One more symptom: When on high RPM I trottle back down the engine does
    not come down right away it will come down slowly.
    
    I will try to play with low and high end again tonight
    
    Thanks for the advise..
    
    Jacques
    

    Re. .3
    
    Check your throttle linkage and make sure it's not binding.
    
    S.

    Regarding 1528.00   Deja Vu !!!!!!!!!!!

  I too had the exact same problem with this engine. After hours/days/gallons 
of fuel I still could not get this engine to run consistently. One time 
it would run great through transitions, then the next time it would 
crap out. I tried everything you did, plus what the other noters 
recommended. None would fix the problem that I was having. None of the 
my club members could figure out what to do with this engine either 
except to trash it.

  Possible vacuum leaks ?????

  One club member I was talking to mentioned that someone in the club 
had the same problem with the same engine. What supposedly worked for 
him was to cut a piece of fuel tubing and slip it over the threaded 
barrel (?) of the high speed needle as far as possible toward the 
carb, then screw in the high speed needle itself making sure that 
the end of the tubing facing away from the carb. covered the end of 
the high speed needle closest to the carb. This would in effect cut 
off the vacuum leak that was occurring around the high speed needle. 
The club member said it did correct the guys problem. I tried it, it 
worked for a short time, then it started crapping out again.

  I was also in contact with Royal trying to resolve this problem. What 
they told me to do was to adjust the needles to get optimum performance 
and once set, put CA glue into the hole around the idle mixture adjustment 
screw/O ring to lock it in place ! WHAT !!  I then asked is there a problem 
with the carb in order to have to glue in the mixture screw, he said no. 
Yea Right !!! He said other people calling in with this problem were using 
CA and it was correcting their problem. Well I tried it, guess what ?? Still 
ran like crap.

  Bad O rings/Vacuum leak ????

  I also noticed that the O rings seemed to be deteriorating. I noticed 
black goo around the needle seats and the needles themselves when I 
dismantled the carb checking for dirt. I would clean the carb, run the 
engine and pull the needles (High Speed/Idle mixture) out, and found the 
black goo again. The Nitro may have been eating them up creating a 
vacuum leak or to cause the needles to move through vibration, hence 
the CA. I give up !!

  The Royal that I owned was older than yours, but I can't help put 
feel that there is something wrong with the original design of the carb.
I have talked to owners of the newer Royals and they don't seem to 
have a problem. Maybe we just got a bad lot of engines/carbs. 

  But believe it or not, I was able to correct all the problems I was 
having with this engine, and it was something I should have done from 
the beginning.

  I bought an ENYA !!!!!!  

    There is the possibility that there is a problem with the carb. But
    FIRST make usre you have the needles set correctly. What you describe
    is a classic case of bad settings.
    
    Now, assuming that you have everything set up correctly, you may find
    that it will run good for a short time, then start acting up again.
    
    I, and others, had the same basic problem with the Magnum 45 Pro's. I
    sent mine back and was told that the spray bar, which is press fit, 
    was not tight enough. There was a "batch" of carbs that had this
    problem. What they did was set the spray bar, and then retrofitted a
    set screw to hold it in place. Before the fix, you could set the engine
    and it would run fine. However after a short running time, the
    vibration would cause the spray bar to turn effectively changing the
    entire carb setting. Since the fix, I have had no problems that I
    can attribute to the motor.
    
    Just something else to consider.

    Try an OS carb.
    
    The problemn with all of the faximilies of an OS engine is that the
    carb is never copied very well. Put an OS carb on it and it will run
    much better.
    
    Regards,
    
    EVL-1

    You might try a Perry Carb, its a viable comercially available
    replacement.
    
    On my Royal .46, I did the following:
    
    Took the muffler gasket out, made sure the surfaces were flat
    and then put a thin layer of high temp silicon on them and bolted them
    back together.  Then I sealed the needle valve with teflon tape.  The
    carb was very carefully sealed with high temp silicone.  Be very
    careful not to get silicon into the carb mount on the engine case.  I
    would recommend using teflon tape on any screw instead of glue.  The
    back cover was removed and the very thin paper gasket was very lightly
    coated with high temp silicon, allowed to dry and then reintalled.
    
    All of these sealing improvements come from 1/8th car racing practice
    but transfer to airplanes real well.
    
    Will
      

    I get a reaction every time somebody asks me what engine to buy. I give
    them a couple of choices of well known reliable brands and invariably I
    get, 
    
    "But I can buy an ASP or a Magnum or a Royal for $20 Less! - What
     do I get for $20 more?".
    
    I should reply "Look what you get for $20 less".
    
    I tried the cheaper engines a couple of seasons ago. By the time I had
    damaged a few planes from engine failure at bad times, bought new carbs
    or carb parts and tried every engine trick that I knew, I was convinced 
    that the extra $20 or $40 was worth it. Even after buying $40 carb's I did
    not get the power, read rpms, of the engines that had been "copied". :-(
    
    I will now buy what I know is well made.
    
    Instead of seal-it I would suggest sell-it!.   
    
    E.
    

    UPDATE
    
    	Well I did two things on the week end. First I put Teflon on the
    needle valve and ajusted the idle, On the Royal looking at the idle
    screw I went clockwise which I beleive is reducing fuel on this engine.
    
    The engine ran a lot better right away. Still not perfect so I will try
    to seal with high temperature silicone this week. I'll keep you posted.
    
    Thanks all
    
    Jacques
    

    UDATE:
    
    Hi flyers: I have dismentled the Royal 40 and put some Hi Temp. silicon
    on the back plate, on the front plate and on the carburator. I should
    add that due to vibration I lost twice the second half of the muffler
    in flight although I glued it with CA the second time. I then purchase
    a OS muffler and nearly lost the second half as well. Looks like the
    engine is vibrating quite a bit. The prop is balanced so it cannot be
    that. I also notice that the idle screw is quite easy to turn and I
    suspect that in flight the vibration make the screw go one way or
    another changing the low idle setting. I will try putting Loctite on it
    although the setting for the engine to work good makes me turn the
    screw quite deep into the carb. I also notice that some of my head
    screws where comming loose.
    
    The engine is mounted on a plastic fiber engine mount treaded and with
    self locking nuts. The airplane is a Sig Kavalier the nose spinner is
    not the usual cone type, it is the old airplane big nut type.
    One last thing I noticed is that the compression of the engine feels
    less when the engine is hot then when it is cold.
    
    1) Is the vibration normal?
    
    2) What could cause it?
    
    3) Is there any remedy?
    
    Jacques
    
    

    Jaque,
    
    I have a Royal .46.  The muffler is a two part type with a through bolt
    and a nut to hold the back half on.  I had to double nut the through
    bolt to keep the muffler from coming apart.  My .46 requires a deep
    idle screw setting to run correctly too.
    
    Vibration is normal for any single cylinder engine.  Some are worse
    than others.  I have an O.S. .28 that has an ugly vibration at high
    speed that nothing seems to cure.  Unless you have wrecked the plane at
    some point and bent the crank you are probably just getting the normal
    vibration from the motor.  You might try experimenting with a slightly
    out of balance prop and placing the heavy side opposite the the piston
    at the top of its stroke or opposite the piston when its at the bottom
    of its stroke. 
    
    My.46 has the same compression characteristic you describe.  It must
    just be the way the piston and cylinder liner expand and contract when
    hot or cold.
    
    Let us know how your efforts to seal the motor have worked.
    
    Will

Regarding .11
    
>    Hi flyers: I have dismentled the Royal 40 and put some Hi Temp. silicon
>    on the back plate, on the front plate and on the carburator. I should
>    add that due to vibration I lost twice the second half of the muffler
>    in flight although I glued it with CA the second time. 

     POP rivet the muffler together, and you don't have the hassle of 
     checking/tightening the bolts. If I remember correctly, the stock 
     muffler only had one screw holding it together and I had to drill a 
     second one to get it to hold properly and with less chance of 
     vibrating apart with only one rivet.


>    I also notice that the idle screw is quite easy to turn and I
>    suspect that in flight the vibration make the screw go one way or
>    another changing the low idle setting. I will try putting Loctite on it
>    although the setting for the engine to work good makes me turn the
>    screw quite deep into the carb. 

     In my earlier reply, I mentioned that ROYAL recommended that I 
     set the adjustments properly and then put CA around idle mixture 
     screw. They said there wasn't a problem with it moving, but I 
     think otherwise. Sometimes this adjustment would even change as 
     I was trying to get it set up properly. Again check for a vacuum 
     leak around the high speed needle.

     As stated in another earlier note, "Don't SEAL it, SELL it", this 
     is good advice. Even if you get it to run properly, one of your 
     BANDAID'S will probably come unglued.

     I personally spent to much time working on this engine and not 
     enough flying. I mentioned that I bought an ENYA to replace the 
     ROYAL, and I haven't had one bit of trouble. The ENYA 40 SS by the 
     way, has the same mounting holes as the ROYAL.
     
     Best of luck !!

I'm pretty sure this engine has a full length rod down the center of 
the muffler to hold the two ends together. A friend replaced it with 
threaded rod and double nutted it with lock washers. This worked well. 
I agree, it's more fun to fly than to fiddle.

    Flyers,
    
    I agree with you that I should not have to fiddle around with an engine
    like that and I will look at replacing this engine with one off the
    better brand. Unfortunately for the moment my budget does not permit me
    to expense $200.00 CDN for a new engine, so I have to do with what I
    have. My only other solution would be to put my K&B .65 in the
    Kavalier ???. 
    
    I did put teflon on the needle valve and all the Hi temp silicon seem
    to help a lot the engine in running more even. Gluing the idle screw
    with CA after set up would not be my no.1 choice, I would be afraid I
    might have to change it or fine tune it again and not being able
    because of the glue I prefer trying Loctite first. As for the muffler,
    I whas lucky enough that the Hobby shop I go to had half of a muffler
    the first time and GAVE it to me. The second time though I had to by
    another one which is to OS .40 muffler.

Teflon tape may not be enough. A short piece of large fuel tubing might 
be required as well. This will also keep the vibration from making the 
needle change settings.

A nick in the idle screw threads will make it harder to turn but still 
allow for adjustment.

A tip I got from a mate at my club seems worthwhile. I've got a mouse fitted on 
the silencer of my (rather LOUD) Magnum .40. Our field is rather noise-sensitive 
so I wanted to shut it up a bit. Trouble is that it's only held by a clamp, and 
it cost a tenner! I was keen that it shouldn't fall off.....

I've drilled a small hole in the outlet pipe of the mouse, and run some nylon 
covered wire fishing trace from the hole to the front U/C leg (any similar point 
will do). This means that if the mouse does work loose at least it stands a 
chance of staying attached to the 'plane! I used nylon covered wire to cut any 
risk of metal/metal interference from vibration. 

I've now done the same to all my exhausts, and I hope to cut my costs a bit! 8^)

Cheers

Nigel

    Yes the saga continues, here is the lattest:
    
    I was fortunate enough to have in my things a piece of tubing big
    enough to be sliped over the needle valve the leaf spring and
    everything sealing the whole needle valve assembly.
    
    For the first two flight it was a dream the engine was purring like a
    cat keeping the same RPM responding to my command without hesitation. I
    could change the power output as if the engine was brand new. On the
    third flight though after some halleman and loops the engine started
    acting up again. So I landed and fiddle arround with the fuel mixture.
    I open it up a little bit and the engine went back to full RPM. OK I
    said to myself just needed a little bit more no problem RIGHT!. WRONG
    after a few more minutes in the air there it goes again. So back down I
    come cursing at this engine. I filled it back thinking that "well this
    the way I'm going to fly until I can get an OS46SF. Back up I go the
    engine does fine for a while and then after a few minutes of fun goes
    again. So back down one more time. But this time I decide to try
    playing with the needle valve again. So I approach my airplane which is
    waiting for me on idle and before I touched it I decide to try full
    trottle. To my suprise she went to full RPM no problem. So I put up
    straight and after a little while the RPM came down. Back to horizontal
    trottle back to idle for a while then back to full and up again to full
    RPM. So I tried to fly here like that. When ever the RPM goes down when
    it should be full I trottle back to idle for a while, about 5-8 seconde
    and put it back in full and I have no problem.
    
    I tried opening the needle valve to with no result. Now I will try
    opening the idle a little bit. Unless you guys have another idea?.
    
    Jacques
     

    Could it be a temperature problem ?  Have you tried - Nah, not worth
    it. (I mean a tuned pipe and running it 'long' ?)
    
    
    Bernd
    

    I don't recall reading what kind of plane your running this engine in.
    It sounds to me like your either STILL experiencing problems with the
    engine leaning out in the air and overheating, OR, if your flying some
    sort of trainer type airplane, the tank position is typically TOO LOW
    and after a few minutes in the air, the fuel feed becomes a problem.
    These OS knockoffs don't typically have that great of a carb system
    and fuel draw becomes a problem. You might also check to make sure you
    don't have a leak in the pressure line "inside" the tank. It WON'T be
    a problem until such time as the fuel drops below the leak. Then you'll
    loose pressure and start having problems.

    
    Do you have your tank mounted too solidly to the airframe? I made this 
    mistake recently, and at full revs the fuel was foaming. This resulted 
    in bubbles in the carb pipe, and eventually the engine quit. This only 
    happened at or near full revs, because only then did the foaming get 
    bad enough to notice. It's easy to spot because of the bubbles in the 
    pipe to the carb.
    
    Nigel.
    

    I checked the tank, it is at the right height and even a little higher.
    It is surrounded with soft foam. I don't see any bubble in the line.
    As I mentioned before I'm flying a Sig Kavalier which is a upper wing
    intermediate type airplane. The engine could be leanning out when going
    vertical, but opening the needle valve one or two clicks make the RPM
    go down noticebly and it does not prevent the engine from acting up in
    the vertical mode. I could have loss of pressure in the tank although
    it is brand new I will check that.
    
    Jacques
    

    I will put aside once and for all, all things that are not engine
    related. One of my friend is going to loan me his OS46SF for a while.
    I know that his engine work very well, so if it does on mine this will
    point out the engine as the problem.
    
    Jacques
    

    The understatement of the year! :-)
    
    
    EVL-1!. :-)

    Well I did'nt get a chance to try the new engine, on friday I went to
    the field with my whole family so that they could see me fly. Sisters .
    brothers in law, father, they where all there. It whas quite windy but
    I decided to go anyway. I took off no problem, turned right and ran
    face to face with the only other airplane in the air. His is not to bad
    but mine is totalled. We had to find the plane piece by piece. So we
    will have to wait a while to know what is really wrong with the engine. 
    But since I lost the carburator in the crash, now I have the
    opportunity to try an OS carb on it.
    
    Jacques
    

    It was an omen.

    Well you won't beleive it but I saved the Royal 40 from the grave. I
    repaired the old carburator I had for it from a previous crash and both
    a ASP needle valve wich fits nice, resealed everything with high temp
    silicon and put it on an Aircore 40. The engine does the same when set
    right it will run fine for a while and then slow down. The problem
    seems to be overheating. So as a solution I opened the trottle wide in
    order that the RPM drops to about 3/4 of it's optimum. I had no problem
    since. Of course I only get 3/4 of the max power, but it is still
    enough for the Aircore.
    
    
    Jacques
    

If it's overheating, how about down propping it a little to make it run 
cooler? Does it need a good cleaning so it will radiate better? Different 
fuel? More oil? Sounds like a different problem to resolve.

    Over heat it in a blast furnace..............being cruel to be kind..
    
    E x E.

    
    Blimey!
    
    Eric's more "Anti-Royal" than the British press!    8^)
    
    
    Nigel
    

    This what I tried
    
    Fuel: Byron 5%, SIG 5% 
    
    Prop.: 10-6, 11-7
    
    no change
    
    I ran it on the ground full trottle, it held it for 15 20 second and
    then drop down to half RPM and stayed there. When I encrease fuel
    intake so that it runs at 3/4 maxRPM it stays there no problem.
    
    I read some time ago that if the engine is not broken in right it will
    do that and that little could be done at that point to save the engine
    is that true?
    
    I also noticed that the engine vibrates a lot more then the other one
    that whas on the same airplane. I have check all mounting and found
    nothing loose. Maybe it is a manufacturing or design problem. Maybe I
    should try counter balancing with the prop. adding some weight to one
    side of it.
    
    Cleaning? yes there is some dark brown deposit on the fins. I will try
    cleaning them with my dremel and a soft steel wire wheel.
    
    
    Jacques
     
    

    Nice one Nigel!.
    
              

Someone told him Futaba was going to distribute them.

Try a 10x5 prop. Cleaning the brown gunk will help. You'll be surprised.

    Lower RPM with a higher throttle setting says you're going off mixture.
    You are probably not getting enough fuel at full throttle.  This could
    be caused by:
    
    
    Foaming of the fuel - look for bubbles in the line
    
    Not enough muffler pressure - check lines and fittings - don't use ANY
    	extensions on the muffler.
    
    Fuel line too thin - use larger tubing.
    
    This will cause the engine to run hot and lose power.  I would bet on
    the second possibility and check your muffler carefully.  If it isn't
    exactly STOCK make it that way.  I've seen changes to muffler systems
    reduce the tank pressure to ZERO at full throttle which will cause the
    engine to lean out.
    
    These engines are very simple - there has to be a simple explanation to
    your problem.
    
    Charlie
    

    "These engines are very simple. There has to be a simple explanation to
    the prob."
    
    Oh Please!, dont make it that easy. I shall resist.............
    
    E.
    
    

    Well I got it in the air again with lots of fuel.
    one more symptom that seems to indicate vacuum loss: When I land the
    airplane I shot the carb completely and the engine does not stop, I put
    my finger on the card and the engine still runs.
    
    I tried the 10-5 prop. and got no change.
    
    I wish I could takt the plug out blow some color gas into the engine
    and see from where it will comme out.
    
    Jacques

    If you have an air leak between the exhaust manifold and muffler it
    will run like that.  Mine did.
    
    Will

    Well..
    The problem with my Royal 40 is finally solved, I sold an old pattern 
    plane that I had collecting dust and the engine came with it free of
    charge with a word of caution to the new owner.
    
    Now I will get an OS.
    
    Jacques
    

    Good decision.
    
    Engine - E.