Rivera Primo Dual Runner Intake Manifold with 45mm Mikuni Carburetor Kit (DRM) - Manual (Page 3)

DUAL DUAL RUNNER MANIFOLD RUNNER MANIFOLD
DUAL DUAL CARBURET CARBURET OR INST OR INST ALLA ALLA TION TION
4
ADJUSTING THROTTLE FREE-PLAY
HOSES
A. FUEL HOSE - Connect the enclosed fuel hose to the pet-
cock and secure it with an hose clamp (included). Route the
fuel line between the cylinders, below the intake manifold.
Cut off any excess hose before attaching it to the carbure-
tors. Secure the hose with the remaining clamp (included).
B. V.O.E.S - As required, attach the vacuum hose for the
V.O.E.S. to either of the vacuum fittings on the intake mani-
fold. The remaining vacuum fitting should be kept plugged
or\ capped.
C. VENT HOSE 1992 AND LATER- Connect the remaining
fuel hose to the open fittings on the top manifold support
bracket. The hoses may be teed together and run as one
over the rear cylinder head, and then down between the
engine and transmission. Cut the hose off flush with the bot-
tom of the engine.
D. CARBURETOR DRAIN HOSES - Route the two carburetor
drain hoses along the front push rod tube and in front of the
crankcase. Secure them as necessary with cable ties from
the kit.
E. MAP SENSOR - As applicable on Twin Cam models, attach
the MAP Sensor from your stock manifold to the Rivera man-
ifold.
5. AIR CLEANER ASSEMBLY
A. Attach the air cleaner backing plate to the carburetor
assembly with the enclosed 3/8 x 5-1/2" bolt, flat & lock-
washers and self locking nut. Place the air cleaner element
into the groove in the backing plate and finish the assembly
by screwing on the cover plate; be sure that the sleeves are
in place on the screws to prevent crushing the air filter.
CAUTION
USE BLUE LOCTITE ON THE AIR CLEANER SCREWS
TO KEEP THEM FROM VIBRATING LOOSE.
TUNING
A. This set of Dual Mikuni carburetors is unlike others in that
each carb supplies fuel air mix to one cylinder and are
required to be jetted independently. Testing has shown that
if a jet change is made in one carburetor the other will
respond favorably with the same sized jet.
B. Carburetor synchronization is pre-set and under normal
operation should not need re-adjustment. Idle synchroniza-
tion is required for smooth idling. Each carb has an idle
adjuster screw located at the bottom.
Perfectly synchronized idle can be achieved by use of a
"manometer" or "carb stick" (available from Rivera
Engineering). The manometer must be connected to the 2
vacuum fittings on the intake manifold then can be tuned by
following the directions supplied.
If a manometer is not available, satisfactory results can be
achieved by simply adjusting each of the idle screws and
feeling the exhaust pulses at the ends of the mufflers until
they feel equal in strength and the desired idle speed is
achieved.
C. Because the carbs do not use a common intake chamber,
higher than normal vacuum signal strength is generated
within the carburetors compared with a single carburetor or
even dual carburetors feeding into a single manifold. This is
good for performance! Tuning of these carburetors is effect-
ed in the following ways:
1. Idle can be adjusted easily to be very smooth. Or, because
the carburetors can be adjusted independently, can be
adjusted for a lumpy "Drive-in" idle.
2. Large displacement engines will probably require smaller
than stock sized main jets. The stock jet is a 160 in each
carb, which is good for stock engines. An engine of over 96
cubic inches may require a main jet size as small as 140.
Refer to the Mikuni Tuning Manual for tips on determining the
correct main jet size for your engine.
D. Starting a cold motor is made easier by engaging the dual
choke mechanism (unique to the Rivera dual carb kits). The
choke knob matches the idle screw knobs and is located
near the top right hand side of the carburetors (with the rider
seated on the motorcycle). To apply the choke, slide the
knob fully to the left stop. As the engine warms, slide the
knob progressively to the right. To increase or decrease the
sliding pressure on the mechanism slightly tighten or loosen
either one of the assembly screws. With the screws adjust-
ed correctly the knob should stay in the set position.