Spark Plug Info

June 16, 2015

                                    Spark Plugs and Spark Checking

Spark Plugs are important. They’re also cheap and easy to change. The spark plug is the first thing you look at when a motor won’t start. Spark, compression, and fuel are the three main ingredients. Spark plugs come in different sizes and styles. See Parts Department to learn what sizes and styles there are.

Reading spark plugs: The condition of the spark plug tells you about the condition of the engine. A normal spark plug has a light brown coating on the white porcelain insulator, and sharp corners on the center electrode. A high mileage spark plug in a healthy engine looks the same but the electrode corners are rounded. Sparks like to jump from pointy things. A rounded center electrode or way too big a gap might make the engine hard to start. 

Checking for Spark: Remove the spark plug, connect the cap to it, and lay it on the engine so the metal shell touches the engine. Turn the engine over either by pedal starting or by flicking the flywheel with your hand. Little momentary light blue sparks should be jumping the gap, making a “snap” sound each time the piston goes up and down. Modern CDI ignitions are hard to see in bright sunlight, so check for spark in the shade. A bright white, pink, or yellowish spark is bad. That usually indicates a fouled plug. Dim and blue is good, especially if the snap snap snap sound is loud.     


Ignition Parts

July 16, 2014

Mopeds have copper core spark plug wires, that last “forever”. Cars have carbon core wires, that break down when they get old. Moped spark plug caps and ignition coils attach differently. Most screw into the end of the wire. Some spark plug caps have a pointed screw that pokes sideways into the wire near the end. The ends of the copper core get wore out from vibration or burned from arcing. Usually there is enough length to cut off the bad end and reuse the old wire. Always make a pilot hole with a something like a dental pick, before attempting to screw a cap onto a freshly cut wire.  

Spark Plug Cap Rubber

A. Spark Plug Cap Rubber
Screw-on Type
No Resistor
requires nut on plug

Spark Plug Cap LB05F

B. LB05F 500Ω resistor requires no plug nut

NGK Plug Caps Explained

NGK Spark Plug Caps Explained

Spark Plug Cap Screw-On

Screw post goes into copper wire core.

Part # # ←picture#………Description Price      Applications
###### ### ############################# #### ##################################
spark plug cap Sparky little rubber $4 plug cap requires “nut”
A spark plug cap rubber universal $4 plug cap requires “nut”
381001 B spark plug cap NGK LB05F 90 degree $6 plug cap requires no nut
40147826 C spark wire & cap 26″x7mm copper $7 plug cap requires “nut”
D spark plug wire 7mm copper blk per ft N/A plug wire copper (not RFI supressed)
E spark plug wire 5mm copper red per ft $1 plug wire thin red (not RFI supressed)
F spark plug wire boot for cap $1 7mm to 12mm approx.
G spark plug wire adapter 5 to 8mm $2 black plastic sleeve with lip
H79A H ignition coil Bosch 53mm holes $45 Puch, Sachs, Batavus, others
6317 I ignition coil CEV 6317 13-25mm $100 Cimatti and many Italian mopeds
6309 J ignition coil CEV 6309 48mm holes $100 76-86 Tomos A3 with Ducati magneto
H79 K ignition coil Dansi 16-20mm holes $70 Italian mopeds with Morini engines
L ignition coil Motoplat 15-25mm red $70 Derbi mopeds
M ignition coil remake 32mm holes red N/A spark is not as strong as with Bosch coil
23849 ignition coil Novi 32mm posts white N/A Motobecane mopeds – these go bad!
H79B N ignition coil Dansi 16-20mm holes N/A Italian mopeds with Morini engines
230627 ignition coil with CDi unit 95-06 Tomos N/A 94-06 Tomos A35
Bosch Coil

H. Bosch Coil
ground & hot
wire unscrews Germany

CEV 6317 Ignition Coil

I. CEV 6317 Ign. Coil
one wire: hot (ignition)
internal ground type
plug wire is molded in
made in Italy

CEV 6309 Ignition Coil

J. CEV 6309 ignition Coil
one wire M5 post: “hot”
internal ground type
plug wire is molded in
made in Italy

Dansi Ignition Coil

K. Dansi Ignition Coil
2-wire: ground & hot
external ground type
plug wire unscrews
made in Italy

Motoplat Ignition Coil

L. Motoplat Ignition Coil
one wire: hot (ignition)
internal ground
plug wire molded in
made in Spain

Ignition Coil Remake

M. Ignition Coil (modern)
one wire: hot (ignition)
internal ground
plug wire molded in
made in India

A detachable wire is a big advantage. If your dog chews up your spark plug wire, you don’t have to buy a whole new coil (with molded-in wire). It is possible to solder on a new wire, but it will be prone to sparks leaking at the joint. As long as there’s no path to ground nearby, that it not a problem. Any of these coils will function well on any other type of moped or small vintage motorcycle with points and magneto ignition. They are just transformers with different mounting brackets. The Bosch coils seem to give the strongest spark, and are not sensitive to heat, and last “forever”. The only bad thing is the two mounting holes are usually too far apart. To get around this, you can use only one bolt with a  nylock nut.


Spark Plugs

July 16, 2014

Contents:  Welcome    1. Spark Plugs    2. Plug Caps, Wires, Coils    3. Magnetos  4. Points and Condensers Welcome. Universal and CEV are almost finished. Bosch, Dansi (Morini), Motoplat (Derbi), Ducati (Tomos), Novi (Motobecane) will eventually be covered similiarly.

Spark Plug Nut1. Spark Plugs

Spark Plugs are the #1 selling part on a moped. It’s good to have a spare. Spark plugs under normal conditions last for thousands of miles. But can only last 1 mile in a “sick” engine, if the insulator becomes fouled, or coated with semi-conductive carbon (black instead of brown or white). Once the white porcelain insulator becomes fouled, the plug no longer functions. Read about cleaning, gapping, and “reading” spark plugs in the Service Department.  At right, spark plugs are shown with and without the screw-on nut. Some spark plug caps require the nut to be on, while other spark plug caps need it to be left off.

Part # # ←picture#………Description Price      Applications
###### ### ############################# #### ##################################
  S P A R K   P L U G S    f o r   s a l e
380029 11 spark plug 10mmx1/2″ NGK C6HSA $3 tiny 4-strokes like 50 to 70cc per cylinder
380030 11 spark plug 10mmx1/2″ NGK C7HSA $3 tiny 4-strokes like 50 to 70cc per cylinder
380018 11 spark plug 10mmx1/2″ NGK C8HSA $3 tiny 4-strokes like 50 to 70cc per cylinder
380078 10 spark plug 12mmx.472″ NGK D6HA $3 small 4-strokes like 90 to 250cc per cylinder
380034 9 spark plug 12mmx3/4″ NGK D7EA $3 small 4-strokes like 90 to 250cc per cylinder
380036 9 spark plug 12mmx3/4″ NGK D8EA $3 small 4-strokes like 90 to 250cc per cylinder
8 spark plug 14×3/8 NGK BM6A shorty for compact or hand-held equipment
380058 5 spark plug 14×1/2 NGK BP4HS projected $3
380059 5 spark plug 14×1/2 NGK BP5HS projected $3 Honda Express and others
380009 5 spark plug 14×1/2 NGK BP6HS projected $3 Honda Express and others
2B5HS 4 spark plug 14×1/2 NGK B5HS hotter $3 MOST MOPEDS
2B6HS 4 spark plug 14×1/2 NGK B6HS std moped $3 MOST MOPEDS = Champion L89
380013 4 spark plug 14×1/2 NGK B7HS colder $3 some mopeds
4 spark plug 14×1/2 NGK B8HS cold $3
380023 4 spark plug 14×1/2 NGK B9HS way cold $3
1 spark plug 14×3/4 NGK B6ES $3
1 spark plug 14×3/4 NGK B7ES $3 Tomos A55
2B8ES 1 spark plug 14×3/4 NGK B8ES $3 Tomos A55
380061 2 spark plug 14×3/4 NGK BP5ES projected $3 Morini
380008 2 spark plug 14×3/4 NGK BP6ES projected $3 Morini
2 spark plug 14×3/4 NGK BP7ES projected $3 Tomos A55
2 spark plug 14×3/4 NGK BP8ES projected $3 Tomos A55
380086 2 spark plug 14×3/4 NGK BPR6ES resistor $4
380087 2 spark plug 14×3/4 NGK BPR7ES resistor $4 Tomos A55
380196 6 spark plug 14×1/2 NGK BR6HIX iridium $13 most mopeds
380197 6 spark plug 14×1/2 NGK BR7HIX iridium $13 most mopeds
380221 3 spark plug 14×3/4 NGK BR7EIX iridium $13 Tomos A55
many more non-NGK spark plugs