Subaru Robin Power Products EH12-2, EH17-2, EH25-2 manual 21 -@

8-1-2 PILOTSYSTEM
The pilotsystemfeedsthefueltoengineduringidlingandlow-speedoperation.		/"l
The .fuel is fed through the main jet to the pilot jet, where it is metered, and mixed with the air metered
by the pilot air jet.
The fuel-air mixture is fed to the engine through thepilot outlet and the by-pass.
At the idling speed, the fuelis mainly fed from the pilot outlet.
8-1-3 MAIN SYSTEM
The main system feeds the fuel to the engine at medium-and high-speed operation.
The fuel is metered by the main jet and fed to the main nozzle. The air metered by the main air jet is
mixed with the fuel through the bleed holes	in the main nozzle, and the mixture is atomized out	of the

main bore. It is mixed again with the air taken through the air cleaner into an optimum fuel-air mixture, which is supplied to the engine.

8-14 CHOKE

Thechokemaybeusedforeasystartwhenengine is cold.Whentheengineiscrankedwithaclosed choke, the negative pressure applied to the main nozzle increases and draws more fuel accordingly this starting up the engine more easily.

8-2DISASSEMBLYANDREASSEMBLY

Apartfrommechanicalfailures,most of carburetortroublesarecausedbyanincorrectmixingratio,

which may arise mainly due toa clogged up air or fuel passage in jets, or fuel level variations.In order to

assureproperflow of airandfuel,thecarburetormustbekeptcleanata11 times.Thecarburetor disassembly and reassembly procedures are as follows.

8-2-1 THROITLE SYSTEM

(1)Remove the philips screw (1) and throttle valve (2), and pull out the throttle shaft (3).

(2)Thespring (4) canbetakenout byremovingthe throttle stop screw(5).

*Be careful not to damage the throttle valve rim.

8-2-2 CHOKE SYSTEM

(1)Remove the philips screw (6) and choke valve (7), and pull out the choke shaft(8).

(2)When reassembling the choke shaft, make sure that the cutout in the choke valve faces the main air jet. Meanwhile, when reassembling set the rings(9) and (10) at the right position.

8-2-3PILOTSYSTEM

(1)Remove the pilotjet (ll), usingpropertoolsto avoid damage to it.

(2)Reassembly Tightenthepilotjetsecurely.Otherwise,thefuel may leak, causing engine malfunction.

1	2	3	7 %
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13*
18	0

12"----&

Fig. 8-3

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