The Fox Hawk 60RC has several unconventional features that
may require handling different from the motors you are accustomed
to using. Read this instruction manual completely before attempting
to operate or disassemble.
The Fox Hawk 60RC has been developed specifically for Multi
Channel pattern type radio-controlled model airplanes. With optional
large throat carburetor it is suitable for Carrier type control
line models, speed boats, and Pylon racers.
Your Hawk 60 should be mounted in the most rigid and secure
manner possible. If the airplane design calls for a firewall
mount we recommend the Fox one piece metal mount as it is very
rigid. If your airplane is designed for hardwood beam type mounts
be sure that they are well braced between the two beams. A plywood
firewall alone without cross bracing and gussets just doesn't
do the job right. A flimsy motor mount could result not only
in structural damage due to vibration, but can damage the engine
due to foaming of the fuel.
Your Hawk 60 seems to like to turn up so we recommend that
you do not use a propeller larger than 11-7. We recommend the
narrow blade variety such as the power prop blade pattern. In
some cases you may want to tip the propeller slightly or drop
to a 6" pitch. Fox Hawks have been run at speeds in excess
of 25,000 RPM without damage, so do not be uneasy about a higher
than average RPM.
Your Hawk 60RC is quite tolerant to fuel so long as the fuel
has at least 20% oil. We have found no oil equal to castor oil
and recommend that you avoid fuels using synthetic oils exclusively.
Duke's Fuel or Missile Mist work fine and if you want to go the
economy route your Hawk 60 will run quite nicely on a fuel composed
of four parts methanol and one part castor oil.
The Fox long RC plug is recommended.
FUEL TANK INSTALLATION:
The closer you can keep the back of the fuel tank to the carburetor,
the less lean the engine will become in a prolonged climb or
large loop. For this reason we favor the shorter, fatter type
of fuel tank whenever a plane design will permit. If you use
the muffler it is recommended that the tank be connected to the
fitting on the muffler as this seems to help in vertical maneuvers.
No special break-in is required. Go ahead and install it in
your airplane and fly. We do recommend you keep your carburetor
set on the rich side at all times. In the interests of good compression
and long life we have fitted our Hawk as tight as we dare. In
the event yours is fit too close and you have trouble with the
piston seizing (engine stops abruptly on lean) or the bearing
binding (engine loses all power on lean), return it to us and
state your problem and we will hone it out at no charge.
The Fox carburetor is of unique design and it is important
that you understand its operation. Basically, the carburetor
has two rotary valves, both on the same rotating member. Large
notches line up with the air passage and meter the air flow.
On the bypass side there is a smaller notch contoured which gives
matching fuel flow as the barrel is rotated. The contour is such
that the mixture will be lean at idle and very rich at full throttle
position. Additional fuel is provided at idle through another
passage which can be adjusted by the small thumb screw on the
exhaust side. To bring in the high speed adjustments a fuel limiting
needle is positioned on the by-pass side. Both needles screw
in to lean and out to richen. For normal tank installations and
flight conditions, we recommend that the low speed mixture adjustment
be made for maximum RPM and then slowly back the needle out until
the motor speed slows down 500 RPM. The high speed is the same
way, screw the high speed in until maximum RPM is obtained then
back the high speed needle out until the motor slows down 500
RPM. We recommend you use rubber or neoprene fuel line with I.D.
.080 or larger. Vinyl type fuel line tends to harden and leak,
and the silicone (white semi-transparent) type fuel line tends
to slip off badly. The Fox Hawk carburetor is made from the same
casting and parts as our Fox Eagle carburetor, however, the orifice
sizes are different, and the body casting and barrel are different.
We recommend that you make the following inspections every
1. Tighten all screws as tight as practical, including the
rear cover screws.
2. Replace the glow plug with a new one.
3. If you have been using a muffler, we recommend you remove
the muffler and run a tank of fuel through the engine at wide
To disassemble your Fox Hawk 60RC - first remove the rear
cover and the six cylinder head screws. Remove the rear cover
and lift the head and the cylinder out. Do not attempt to remove
the rod at this time. The wrist pin snap ring and wrist pin are
now exposed and must be removed before attempting to remove the
connecting rod. A special tool is normally used to remove the
snap ring. To remove the crankshaft, first remove the thrust
washer, prop washer and nut. The crankshaft can then be forced
back out of its bearings and this process will slide off the
aluminum taper lock.
Re-assembling your Hawk is the reverse of disassembly. Two
precautions must be taken, however.
1. When re-installing the crankshaft be sure that the taper
lock is pushed all the way up against the crankshaft shoulder.
It is usually necessary to support the crankshaft from the inside
on a peg of some kind and tap the taper lock down hard against
the crank shoulder. If this is not done a starter may push the
crankshaft back far enough so that the crank pin will chew up
the rear cover.
2. Position the piston so that the ring pin is on the exhaust
side of the wrist pin otherwise the ring might catch in the ports
which will make an awful mess. When inserting the cylinder over
the piston be sure that the gap on the ring is positioned over