Starting Procedure - Rotax 503 UL Operator's Manual

4) Starting procedure:
4,1) Pre-start check:
Beforc starting engine read section dcaling with staning and cngine htak-in thoroughly. The
service life of thc a[gine is largely detemined by how wcll you follow these instsuctioqs.
Before starting engine be sure your installation is complet€, eosure that all contols opffatc
easily and smootbly, and that you caa operate them instinctively.
Always ensue that you are in a safc run-up a!ea-
Ensurc tluottlc link.ge allows piston valve in carbEetor to bofiom in idle position, Screw out
idle specd adjustmcnt sclgw (no.14, scction 7) until carburcor pistod (no.3) bottoms.
Carefully tum in adjustment scrcw until it engages pisto[ and tum h a fudrer 3 to 3 1/2 full
tums. Check if fuel line is conrlerted ard tank vetrt is oDen.
4,2) Procedure;
On cold engine apply choke fully. Ensure idle position. (Opening throtde will gready rcducc
choke effect lesulting in hard stardng). Make sure ignition switch is on and that you can shut
it offinstandy ifnecessary, Pull starter urtil firDlly engagsd and then pull through vigolously.
Above plocedue should be repeated until engine begins to firc. As soon as elgine stafis, shift
the tbrotde slowly to low speed and rcmove choke as soon as possible (prolonged use of choke
can cause engine to flood,)
Ifthc engine fails to start or operates only on one cylinder, chcck whcther the ignition wiring
is disconnccted or incore{dy connccted to the spark plug connectors or to th€ spark plugs or
the ignitiol s]vitch is in off position.
If Feceding checks do not solve the problem, rcmove the spark plugs and inspecLwet spart
plugs indicate a flooded engine.
To corpct, replace with dry plugs and discontinue use ofchokc, Switch ofrignition. Craok
engine with fully open drotdo to clcar thc excess fucl.
Repeat stan proccdurc.
Dry spark plugs indicatc no fuel in onginc. To inspect, reEove float bowl and cnsue fuel is
present in suficietlt quantity, If not, inspect fuel level in tank, fuel valye and tank ycnt, I-ook
for blockage or obstruction. Corcat 8nd rcpeat st{t proceduc,
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