vhsh 30 handbook

STARTING JET1startingBefore starting the engine, please assure that thecarburettor’s float chamber and the feeding circuitare filled and in case of cold engine, open the starterand go ahead with the ignition. The component, whichinfluences the ignition is the starting jet: higher the value of suchcomponent will be, richer the cold ignition phase with starterinserted will be. This kind of enrichment is active only with thestarter on, therefore it affects only when such component isactuated.IDLE JET2idleFor the idle adjustment we operate on thehrottle valve screw, which moves the “stop”position of the valve itsself.Such a component allows the increase or thedecrease of the rpms at idle. Together with the adjustment of therpm, we have to set the “title” i.e. the quantity of air/fuel at idle.Operate on the air screw, which acts as a “leaner”: by closing it weget an enrichment; by opening it a leaningThe infl uence of such a component, besides on the idle regularity,is detectable on the total or partial fast openings and on the returnsat idle: if during the fast openings from idle we should notice somepauses, faults for lean, we have to tighten the screw in order to havean enrichment; we need to operate progressively by moving thescrew of ¼ turns each time.If the fault is due to too much fuel, we will have to open the air screw.It’s important to have a correct engine idle in order to have a partialand/or total good pick up without any hesitation and without shuttingoff during the release and return at idle condition.The adjustment of the title at idle and of the set rpm is importanteven to improve the cold startings (with starter on) and the warmstartings (with starter off).

EMULSION TUBEMAIN JETFLOAT ARM5wideopen throttleThe component, which mainly infl uences thewide open throttle is the main jet. As a matter offact the variation of such a component, increasesor decreases the fuel quantity at the wide openthrottle or partially wide open throttle ( up to one forth of theventuri’s section).We may suggest to start with a main jet of 5-9 points higher thanthe standard adjustment and go down progressively up to reach thecompromise limit between performances and temperatures in orderto avoid seizures or detonations for lean condition. If under powerconditions that means with a completely wide open throttle valve orengine under load, we should need to change the fuel quantity, bychanging the fuel level in the fl oat chamber, we may change thefl oats With lighter fl oats the level decreases, having in such a way aleaning of the power and of the transient state in the fast totalopenings, on the contrary the heaviest ones increase thelevel, enriching the power and the transient state itself.It’s important to check if the trim of the floats’ arm, withthe carburettor up side down, is parallel to the fl oatchamber level and to an height of 4,0 +/- 0,3 mm at theend of the chamber itself.WOT3/41/21/41/8Throttle valve at idleidle air screw and idle jetsthrottle valve champferatomizer and conical needlemain jetThe above picture represents the choke and shows the infl uence of thedifferent components as far as the throttle gas opening is concerned; it’sjust indicative and it’s however a function of the combination of the differentcomponents and of the geometrical features of the conical needle.

CONICAL NEEDLESFEATURES - K TYPEcode T ref.N Ø A Ø B CK 001 3 8530.X.08 2.45 1.75 37.00K 002 3 8530.X.08 2.45 1.75 42.00K 003 3 8530.X.08 2.50 1.50 39.00K 004 3 8530.X.08 2.45 1.50 39.00K 005 3 8530.X.08 2.45 1.50 37.00K 006 3 8530.X.08 2.45 1.75 39.00K 007 3 8530.X.08 2.45 1.25 39.00K 008 3 8530.X.08 2.50 1.50 37.00K 009 3 8530.X.08 2.45 1.50 42.00K 011 3 8530.X.08 2.50 1.25 39.00K 012 3 8530.X.08 2.48 1.75 32.00K 013 4 8530.X.08 2.45 1.25 38.00K 014 3 8530.X.08 2.48 1.75 33.00K 015 3 8530.X.08 2.50 0.60 36.00K 016 3 8530.X.08 2.50 1.75 39.00K 017 3 8530.X.08 2.42 1.75 40.00K 018 4 8530.X.08 2.50 1.40 38.00K 019 4 8530.X.08 2.50 1.40 40.00K 020 4 8530.X.08 2.50 1.40 42.00K 021* 4 8530.X.08 2.50 1.80 38.00K 022* 4 8530.X.08 2.50 1.80 40.00K 023* 4 8530.X.08 2.50 1.80 42.00K 027* 5 8530.X.08 2.50 1.80 44.00K 028 5 8530.X.08 2.50 1.80 41.00K 029 4 8530.X.08 2.45 1.25 42.00K 032 4 8530.X.08 2.48 1.70 44.00K 035 4 8530.X.08 2.50 1.40 43.00K 051 4 8530.X.08 2.52 1.40 43.00The conical needle of thebasic K28 adjustment isblue coloured highlighted.The conical needles (*),due to the specifi cgeometricalcharacteristic, act fromthe wide open throttle tomore than half choke.

The SETTING UP KITincludes:CARBURETTORSDELLORTOTo lean Basic adjustment To enrichEmulsionated idle jet(13086.X.02)48 - 5052 - 5545 160 264 DP 40 K28 4,0 g35 - 3840 - 42Main jet(6413.X.02)160-165168-170172-175Atomizer(12539.X.28)Throttle valve(16565.X.64)266 DP 30 - 35Conical needle(8530.X.08)K23K27150-152155-158 262 DP 45 - 50 K21K22Float(15760.X.80)5,2 g3,6 g

FUEL PUMPP34 - PB2General CharacteristicsPneumaticfuel pump for motorcycles’ applicationAssembly by screws and relevant reference pointsPumping bydiaphragmBy pass internal regulatorOperating frequency: 10.000 pulses/min.Main Technical FeaturesOperation by pressure variationNominal air fl ow: ~ 55 l/hNominal pressure: 0,05-0,1 barDirect or at distance pneumatic connectionsPlastic body“Umbrella” check valves and seats machined in the bodyWeight: 100 grFuel pump 52628-78 review kitIMPORTANTDelivery L/hPerformances6050403020In order to get informationon the engine and allrecommendations for acorrect installation of theFuel Pump P34-PB2,DELL’ORTO’STECHNICAL SERVICEprepared a TECHNICALDATA FORM.Please fi ll it in and return itto DELL’ORTO S.p.A.1001 2 3 4 5 6 7 8 9 10 11 12 (X1000)Pulses X 1.000 min.

Phone +39 031.7692111Fax +39 031.7692216www.prjteam.comwww.dellorto.itstaff@dellorto.itvia Kennedy, 7ITALYITALYCabiate 22060 CO