Chapter 12: Setup & Maintenance
Parts & Service
on non-motor hardware improvements
Winterizing your Paramotor by Alex Varv
Go down to Testing for Spark to see if this
is the problem
See also Simonini
Ignition, Broken Wire & Charging Issues,
Top 80 Coil
Spark Plug, Cap & Related
The most common
cause of ignition related problems is a bad plug. They can look fine but be
broken internally. They're cheap and easy to replace so start there. Other
- The cap's screw is bad. Caps frequently attach to the spark plug wire
by screwing a center screw portion into the center of the wire. If the
screw misses the wire or is barely touching it or is touching any of the
surrounding braid, there will be no spark.
- The cap is fouled with debris. Pull the cap off and see if there is
any debris. Sometimes there is rubber leftover from manufacturing that
gets in the way of making good contact.
- The cap is loose. If the cap pulls off too easily then it is more
likely to get fouled with black, sooty carbon which could decrease
connectivity. The black substance comes from the loose plug arcing.
- The Spark plug end is worn or loose. If you have the type of plug
where the tip screws on, it may be loose.
- Incorrectly gapped. Some motors are very sensitive to having the
correct gap. A large gap requires a stronger spark.
- Wire disconnected at the coil. These sometimes break off from
- The wire is broken internally. It MAY run but gradually get harder
to start or start cutting out.
- The fine windings inside the coil are shorting out. This would
reveal itself through a low coil resistance. According to Paul Czernecki
of Planet PPG, on Simoninis at least, using the red & blue wires, 300
ohms is what new units get, and 160 ohms is so low that it won't produce
- The Spark Plug has come partially unscrewed. Usually it blows out
completely, but in rare cases, combustion chamber pressures will damage
the threads, leaving the spark plug imbedded but difficult to unscrew.
In that case, you must repair the threads. Don't just force it out, use
this field fix.
If bare or abraded (insulation
worn through) kill switch
wire is touching any part of the frame or return wire on its way to the
kill switch, it will ground the coil just like pressing the kill button. There will be no spark. Disconnect the wire and ed. If you suspect that
the fuel flow is insufficient there are two possibilities. A blockage in
the fuel path or vent path.
2008 June 17 It has been reported that an ignition based tachometer can cause
problems for the kill switch. You press the kill switch but the motor
doesn't shut off. So far it has only been reported on Black Devil motors
but may apply to others. The problem happens when the tach pick-up wire
has too many windings around the spark plug lead. It's fixed by reducing
the number of windings.
Paul Lundquist, a long time diesel mechanic,
suggests also that the two wires going to the tach are TWISTED. This
counteracts the induction caused by current flow. If these wires are
NOT twisted, electrical devices (in trucks anyway) can have strange
problems. If you only use one wire, as many do, don't worry about
These are rarely
the problem, thankfully, since they're a pain to replace on some motors. Most likely one of the wires has vibrated off or it has shorted out
internally. Other possible coil-related problems:
- Broken Ground strap around the outside part of the coil on some
- Broken wire.
- On E-start, stator coil can prevent a spark.
The coil is replace on the Black Devil 172 motor by removing the hand
start mechanism with 4 nuts and removing the 2 hex bolts of the coil.
Coil (Ignition) Wire Breaking
On some models of Simonini (and probably others) there is a problem with
one of the coil wires breaking. Here is the solution. Clean the electrical
connections with Acetone. Crimp a connector onto 6" of Deans noodle Purple
wire and run that from the coil to the other connection point. Thanks to
John Black for the tip. See
Several things you can do to
check if there's a spark:
- Spray starter fluid (available from most auto parts stores) in the air
intake and see if the motor fires. If it does, you've got spark. If it
doesn't, investigate further.
- Take the machine to a dark place (garage or similar). Remove the spark
plug, put the cap back on, lay the plug so that it's threads are touching
the cylinder and pull the start cord. You should see a spark as the motor
turns over. You may have to cup the spark plug with your hand to see it.
Pull it briskly.
- Buy and use a spark plug tester.
- Put your thumb across the gap and pull the cord. Pain=spark although,
if you cannot visibly see a spark, there may simply be insufficient voltage
from the coil.
- The spark should have a blue tint, yellow means it may be too weak.