First published 5 January
Webers and spark plugs? Learn how to tune them. The carburetor
datas are here.
NGK B7ES spark plugs
The Golden Lodge 2HL is a great spark plug.
However, During the last years I have been using the NGK sparks. Be
careful so you get the correct plug for your 105 engine. I use B7ES
and not the BP7ES. The "P" indicates that the electrode is
a bit further down on the spark plug. The NGK refer to this as
"projected insulator". The B7ES have the correct
temperature and the electrode is not causing picking and maybe
causing other ignition problems.
first letter "B" means the threading. In Europe
"B" means 14mm thread European standard (M14 x 1.25).
letter "E" means the length of the threading, in this
case 19 mm.
shorter threading has "H" as an indicator, = 12.7 mm.
"7" tells us about the temperature of the spark plug.
means "projected insulator".
"S" is just for information about the material in the
plug. NGK has this S to tell that there is a copper in the core
of the plug.
If I understand the NGK information correct,
driving with a "P" spark plug might give you trouble with
pinking or what ever you call it over there. The ignition module is
made by Bosch # 0227 100 111. Same as Peugot, CitroŽn and Volvo
among others use.
Weber tuning for me!
tuning is here in PDF, 3.6Mb to download
and here's yet another Spica manual www.shorey.net
I have Weber carbs on my Spider. Here's the
adjustment procedure as I do it. The procedure is the same on
Dellorto. The entire manuaul is here to for
you to download. Synchro tools and 4 column manometer kit are in
stock here www.racecar.co.uk
Start by making sure that the CHOKE lever
under the dash is pushed in fully. Check that the choke cable is
allowing the enrichment levers on the back of the Webers return to
their stops. Then loosen the clamps with a 7 mm wrench and push the
levers to their stops. Do not forget to tighten the clamp screws.
Check the FUEL HOSES for cracks
(especially near the ends) or leaks. Replace them if they look too
bad. Empty the water separator and inspect or
replace the FILTER. Now, check for FULL
THROTTLE OPENING. Have a helper step on the accelerator pedal
while you watch the throttle shafts rotate to the fully open
position. Gently adjust the linkage, if necessary. Make sure that
the bellcrank under the carbs is not sticking on its shaft.
Check and make sure that the throttles are SYNCHRONIZED.
Remove the brass plug (above the off-idle holes) of each carburetor
section. Shine a flashlight into each of the holes to see that the
edge of each throttle plate is aligned with the same hole when the
throttle is slightly open. The brass plug is removed on this photo,
red dot. There are three holes. Gently adjust the rear carburetor
throttle by tampering with the idle adjusting screw, yellow dot.
Check that you can see the throttle through one of the holes.
Adjust the spring- loaded screw, green dot, in
the linkage between the two Webers until you can see the throttle
through the corresponding hole. Use a mirror and a light and shine
through the holes vy the air cleaner. Then you have the carbs
synchronized Now gently adjust the idle screw a few turns. Later,
you will have to adjust this screw again to get the proper idling
revs. The spring- loaded screw will not need any attention any more.
Make sure that the Idle Stop Screw is NOT against
its stop when you are making the adjustment or you will be even more
Check the FLOAT LEVEL.
A) Remove some fuel from the carbs and let the engine idle for
two minutes. Remove the wingnut caps.
B) Then, use the depth gauge end of vernier caliper to measure
from the top of the lower shelf to the top of the fuel surface. DCOE
spec = 1.14 inch (29 mm+4.5 mm). If the depth is NOT
correct, the top plate of the carburetor must be removed. Carefully
bend the tab on the float assembly that touches the needle valve.
Reassemble and test the float level as before..
Check for Intake System AIR LEAKS
while engine is running. Wiggle the carbs and pour water on the
donuts and listen for a change in the engine speed.
Adjust the IDLE MIXTURE.
- Raise the idle speed to 1000-1500 rpm by turning the Idle Stop
Screw. It does not matter if the rev counter is accurate as long
as you keep a steady reading. Stop the engine. Remove the spark
plug wires from the two rear spark plugs and ground the wires.
Turn each of the front two Idle Mixture Screws clockwise and
count the number of turns until the Idle Mixture Screw touches
its seat. Normally, this screw is about 3/4 of a turn from its
- Restart the engine. Adjust the two front idle mixture screws
so that the engine rpm is the highest possible. Allow a few
seconds after each adjustment for the engine to respond to the
- Stop the engine. Reconnect the two rear plug wires and
disconnect and ground the two front plug wires. Adjust the two
rear idle mixture screws. NOTE: The idle speed should be
the same when the engine is running on the front two or on the
rear two barrels.
- Stop the engine and reconnect the wires. Turn the Idle Stop
Screw clockwise to the original position. Start the engine.