FPE 6.8 INSTALLATION  & OPERATION INSTRUCTIONS

Engine Mounting:

Engine mounting should be done using 4 10-32 socket head bolts of high quality. The bolt pattern is 3.00” horizontally by 3.250” (3 1/4”) vertically (total width and height). Draw thrust line and engine center line on fire wall, measure right and left 1.500” (1 1/2”) from center line, and then 1.625” (1 5/8”) up and down from thrust line (see enclosed mounting template). The throttle can be hooked up via a sullivan gold rod or whatever method you prefer (this is a spark ignition engine so if using steel push rod for throttle be sure to isolate both ends with nylon or plastic rod ends). BE SURE TO INSTALL THE GROUND WIRE ON THE BOLT LOCATED BESIDE SPARK PLUG BEFORE IGNITION IS TURNED ON – FAILURE TO DO SO WILL BLOW OUT THE IGNITION SENSOR. DO NOT TURN ENGINE OVER WITH SPARK PLUG WIRE NOT ATTACHED. Always range check airplane with ENGINE RUNNING. PLANE MUST BE HELD IN CASE OF RADIO FAILURE – before flying plane. Keep all ignition components as far away from radio gear as possible.

 

Suggested gas/oil mix:

I have run numerous brands of oil and recommend Bell Ray MC-1 at a 50:1 ratio or Golden Specto at a 50:1 ratio. I believe any good quality synthetic oil at the manufacturers’ ratio will be fine. If they give variable ratios, I recommend 50:1 ratio with high test gas. Running oil contents with more oil than recommended can carbon engine or in the extreme case, could stick rings in piston.

 

Suggested ignition battery:

A 4.8 volt battery must be used to give ignition power. A 1650Ni Mah AA size or 1800 Mah sub C size battery should provide at least six 10 minute flights. As with any other ni-cad battery, check batter voltage between flights to be safe.

 

Suggested propellers:

            Menz S 27x10

            Menz S 28x10

            3W 27x10

            NX 27x10

            Biela 27x10

            Mejzlik 28x10

-If selecting other sizes or brands, the recommended maximum RPM on ground should be between 5700 and 6300 rpm.

 Propeller bolt pattern is 6 bolts on a 1.500” (1 ½”) bolt circle. A propeller drill jig is available

 

Engine starting tips:

            Turn choke to a fully closed position.

            Turn on ignition.

            Set throttle to slightly open position.

            **(BE SURE THE PLANE IS HELD SECURLY AND USE A HEAVY GLOVE FOR SAFETY REASONS)**

            Flip propeller until engine starts (engine will start and run only a few seconds with the choke on).

            After engine quits, turn choke off and return engine throttle to IDLE position.

            Flip engine until start (usually 2-4 flips).

            Let engine idle for short time if engine is cold.

 Tuning tips:

Initial needle settings are 1 3/4 both Low and High. (Turns out from seat)

After engine has warmed up:

If engine stutters when going from idle to full speed it is lean on Low-end needle. Turn out low-end needle until a smooth transition is achieved.

High end setting can be best found by starting at a rich setting (engine is rich when running rough at full throttle – a lean setting will either quit or lose RPM). Lean High end needle until the popping or roughness stops (for initial flight a slightly rich setting is better than a lean setting ,a rich setting will usually run slightly rough, but a lean setting will stall engine).

 

TROUBLE SHOOTING

Engine won't start:

Make sure carb has fuel

Make sure battery for ignition is charged

Make sure engine has spark (if testing spark make sure the plug is grounded to engine before turning on ignition or tuning over engine. IF PLUG IS NOT GOUNDED IT WILL BLOW IGNITION PICKUP SENSOR.

If engine has been running well up to this point don’t adjust needle settings, gas engines normally do not change tuning. Check for dirt in filter, or in carb screen.

 

Engine runs fine on ground but quits or runs rough in air:

If engine quits in air shortly after takeoff, there could be air affecting the atmospheric vent on carb. This is the hole in center of sheet metal plate located on the front of carb. The diaphragm is under this plate and it activates the needle valve to let gas through the carb. Unfortunately the cure may be different for each plane. Some cures have been soldering hollow brass tube on hole and pointing away from airstream, or putting a hose (like gas fuel line on the brass tube) and routing back in cowling or possibly into fuse. I have also seen a tube soldered on and brought out flush with the carb opening. If you solder the brass tube onto plate, plate MUST BE TAKEN OFF of carb to avoid burning the diaphragm.

 

If engine runs fine on ground but breaks up in air:

This could be one of two problems:

1. High speed needle could be slightly rich, adjust needle in very small amount i.e. 1/8 turn and fly again. If no change, try another 1/8 turn etc. If no change, you might want to try step 2 before more tuning.

2. Ignition timing too far advanced. To reset engine timing, loosen two bolts holding the sensor mount and rotate slightly (approx. 1/16”) in the direction of engine rotation to retard the timing (1/16” = approx. 3 1/2 degrees of timing)

*Specifications

DISPLACEMENT	6.8 cubic inches (111cc)
WEIGHT	119 ounces (including mufflers)
LENGTH (prop washer to backplate)	7.0 in
PROPELLER BOLT PATTERN	6 bolt, 1 1/2’” Diameter Bolt Circle
PROPELLER BOLTS	6, 8-32 x 2” Socket Head Bolts
SPARK PLUG	Champion RDJ8J (with .025” gap)
FACTORY CARBURETOR SETTINGS	1 3/4 turns out (both High and Low needles)

*Specifications may change without notice.

SERVICE & REPAIR	TECHNICAL ASSISTANCE
FIRST PLACE ENGINES	SIG MANUFACTURING CO., INC.
209 Conneaut Lake Road	401-7 South Front St.
Greenville, PA 16125	Montezuma, IA 50171-0520
Telephone:  (724) 588-9559	Telephone:  (641)623-5154
Fax:               (724) 588-9550	Fax:               (641)623-3922
e-mail:          kurt@fpengines.com	e-mail:             mail@sigmfg.com