Model Forum / Radio Controlled / Air Models / April 2004

Not really familiar with that engine, but sounds like you may have a
restriction (some fuzz or a speck of dirt) in the carburetor near the needle
valve. You might want to try removing the high speed needle valve and flush the
carb out with some glow fuel. Just put your fuel pump on the nipple where the
fuel line connects & give it a few pumps, in and out. If that doesn't help,
maybe try removing & cleaning the carb. Hope that helps !! Good luck. - Ray

anyone familiar with this engine? I have tried everything but cannot get it
to
run reliably at full throttle. I though the problem was an undersized fuel
line in the gas tank to th eclunk. Relaced it today along with all the fuel
lines, no difference...It idles fine, goes to about 50% throttle, that's ok,
anything above 50% it will die...I have messed with the carb settings to no
end and cannot get it to attain full throttle, it also dies going
vertical....Will run all day going straight and level at 1/2 throttle but
that
ain't no fun!...Any help is appreciated.....
=============================
I saw a thread on RCU that described a similar issue with an OS engine.  The
suggestion of cause was that the low end may be set too lean and tghere's
not enough total fuel flow at full throttle.  Recommended solution was
richen the bottom end a lot, even to thge point it won't idle without the
glow driver.  Get the high speed set, then start working on the low end;
readjusting the high end after each adjustment to the low end.

I have a TT61Pro that was hard to start, wouldn't transition, general pain
in my tail.  All of the 'experts' at the club said it's too rich on the
bottom and loading up.  Leaning the low end didn't help.  My brother and I
are not 'experts' and got to the field early one day and richened the low
end by 1/2 turn.  Hmmm, a little better.  Another 1/4 turn, not too bad.  A
few more little tweaks richer and the engine starts instantly, idles,
transitions, an absolute pleasure.

Carrell

May I suggest looking into a comparable electric motor?  Much more powerful
and efficient, and just plain better.

(potato suit on)

J

I would tend to agree that there is something in the high speed needle
spraybar. Try the glow fuel flush or I use compressed air (about 20-25psi)
to blow it out. If it is new there may be some machining filings or a burr
in the tube causing a disruption of fuel flow.

As far as large electric models go, there was an article in Fly RC a few
months ago that listed the cost for a .60 sized aerobatic A/C with the motor
costing around $300 and the batteries (2) costing $375 each. Of course the
ESC was another $275 or so. I can fly a LONG time for that much in glow fuel
on a .60 sized plane and not have to buy a new charger or worry about my
power supply catching fire if handled less than delicatly. Electric HAS come
a long way but until costs go down considerably, I'll stick with glow or gas
(even cheaper).

Jim W.

 Gotta remember that the muffler is a mini tuned pipe. Sometimes when
the low speed needle is set too rich the engine can't "get on" the pipe.

  I had this happen with a Tower .46 that I put back into service a
couple of weeks ago.  It started and idled fine but but started to rev
up and died when the throttle was opened.  This was with the glow
battery connected.  Since it would start at idle without choking it
hadn't gone lean.  So I leaned the low speed needle an eighth turn at a
time 'til it would rev up, then set the high speed normally.  Then I
tried the pinch test at ldle.  It died right away, so I opened the low
speed maybe 1/16th and flew it.  It ran out the tank through three
flights, so it must be set pretty close. ;^)

  You have to remember that the engine runs on the low speed needle up
until about 3/4 to 7/8 of the throttle travel.

  Cheers,

   CR