NB: These instructions are given for guidance only and cannot engage the author's liability in the event of misinterpretation, failure to assess the vehicle's actual condition and/or non-conformity, unsuitable mechanical practice or the use of inappropriate tools. It is strongly recommended to have this kit fitted by a professional.
The Mikuni RS36 carburettors supplied by Topham are proven, later-generation equipment compared with the original carburettors. This results in much more precise metering of the fuel mixture admitted by the engine, hence smoother and more flexible running and lower fuel consumption.
They are also an advantageous replacement for the original carburettors in terms of spare-parts availability and price, and they hold their mixture and synchronisation settings longer.
The Mikuni rack is already mechanically adapted for fitting to the Laverda triple engine (spacing, bulk, arrangement of the fuel unions…). The base settings are pre-set for Laverda 1000 or 1200 engines in their most common form (compression ratio, camshafts and exhaust broadly standard). These settings therefore suit the vast majority of these machines. They should nonetheless be checked, or even fine-tuned, on tuned or non-standard engines: most of the time it will be enough to fit larger main jets.
Installation
- Remove the original Dell'Orto carburettor rack.
- Remove the throttle grip and cables (keep the original switchgear for the starter and kill-switch functions).
- Remove the intake manifolds, unions and thermal spacers. Check the condition of the studs and the manifold sealing faces on the head; true up or repair if necessary.
- If fitting the Redax Laverda angled intake-manifold kit, remove the studs (replaced by the screws supplied in the kit).
- Fit the new intake manifolds with their O-rings, spacers, unions and clamps. Tighten the fixing screws with their spring washers without overtightening.
- Push the carburettor rack onto the rubber connectors of the intake manifolds and tighten the clamps.
- Check the condition and sealing of the fuel taps; repair or replace them if in doubt.
- Connect the carburettors to the fuel taps with new hose, preferably green transparent as original (JLO-Tech ref.: CARB010).
- Fit the new throttle grip, install the push/pull cables and adjust them leaving a little free play. Check that the slides open and close freely, fully and without stiff spots.
- Check that the static synchronisation of the slides (pre-set at the factory) has not moved during fitting; correct if necessary.
- Set the static slide opening to the minimum for idle.
- Open the fuel taps and check for any leaks.
- Start the engine, set the idle to about 1000 rpm then, once warm, fine-tune the mixture screws to obtain the smoothest possible idle. Reset the idle to 1000 rpm.
- After 100 km, check the synchronisation again.
Precautions with Mikuni carburettors
- As with the Dell'Orto, make sure to use clean fuel (beware of rusty or poorly cleaned tanks).
- Never over-tighten the mixture screws against their seat: this could break their tips inside the carburettor body.