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Spark Plug Ends
01/13/03
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Stock VW 1200, 1300, 1500 & 1600cc Air Cooled Motors
all use the same Plug "Bosch W8AC"
Stock heads use the 3/8" reach spark Plugs but most High Performance
heads use the 3/4" reach plugs.
Make absolutely sure you have the correct length (reach) as they can not
be interchanged.
We have never had good luck with the Platinum Plugs in stock motors but
worked OK in Race Motors.
Plug Gap is .024" to .028" and should be torqued to 22 to 29 Ft
Lbs. The threads are 14 x 1.25mm
The small threaded terminal should be discarded as they are not used with VW
plug wires. Be Sure the engine is cool before replacing spark plugs. It's best
to install new washers when replacing used spark plugs. It's not a bad idea to
lubricate the threads with antiseize compound. Especially with new heads.
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#
1 = Electrodes - Set Gap at .024" / .028"
# 2 = Porcelain insulator
# 3 = Threads 14 x 1.25mm by 3/8" long
# 4 = Spark plug information on body of plug
Bosch W8AC for
stock VW's
# 5 = Small terminal cap not used with VW wires
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Inspect |
Condition |
Corrective Action |
Insulator # 2 |
Cracks, chipped
Very white color |
Replace spark plug.
Clean and reinstall.
Consult your local mechanic. |
Electrode # 1 |
Worn down, broken, warped |
Replace spark plug. |
Electrode
&
Insulator
# 1 & # 2 |
Light gray, tan or light brown in color
Large amounts of flaky
white or yellow deposits |
Normal condition. Clean and
reinstall.
Change brand of fuel.
Clean and reinstall.
|
All Spark Plugs # 4 |
Large amounts of fluffy,
dry, black deposits
Wet or oily tips |
Clean and reinstall.
Consult your local mechanic.
Replace spark plug.
Consult your local mechanic. |
Single Spark Plug # 4 |
Large amounts of flaky
white or yellow deposits |
Replace spark plug and
spark plug wire. |
Depending on style of driving the normal plug gap increases about .001"
for every 2500 miles driven.
As the gap increases, the voltage required to fire the plug also increases.
The voltage required to fire the plug at high RPM is about 2 or 3 times as much
as required at idle.
The more the fuel/air ratio is off the more voltage is required to fire the
plug.
Be sure to remove the Plug Wire by pulling on the boot not the wire, otherwise
the connection inside the boot may become separated.
Only remove the spark plugs when engine is cold if at all possible.
If you must remove them from a hot motor, be sure to first remove the plugs when
cold and then reinstall them with the torque on the light side.
Normal spark plug torque is about 22 foot lbs.
Use a round-wire type gapping tool on used plugs not the flat feeler gage.
The normal spark plug color is gray or light brown. The problem is some fuels
produced today change the plug color slightly. Black & sooty indicates out
of tune. Never try to take a plug reading with new spark plugs. It takes about a
quarter mile for the plug color to stabilize. You will loose the color just
pulling off the road.
Gas additives in modern pump gas can change the plug color, so it's harder to
get accurate plug reading then years back.
When taking plug readings run the 1/4 mile at the rpm you wish to check and cut
clean. In other words turn off the ignition as you depress the clutch before
pulling off the road.
Plug reading is an art, we will try later to add a section to get you
started.
Spark plugs can have a lot wider heat range today then the plugs produced in
the 70 & 80's
Never use Helicoil inserts to repair spark plug holes, always use the sleeve
type of the correct length. It's best to have the head off so you can make
sure every thing is flush in the combustion chamber.
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Victor Comp. Products Inc. **--Vic's--**Phone
816-650-3535 • 230 S Hudson St., Buckner, Missouri, 64016, US
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