Dnepr MT9 - Engine Reconditioning

IV. ENGINE RECONDITIONING
1. DISMANTLING AND ASSEMBLI~o-'I'HE ENGINE
Removal and Installat ion of the Cylinder Head
To remove the cyl inder h ead from the e ngin e, pr ocee d as fol -
:ows:
ease off the nuts of the front st ud securing the eng ine;
unscr ew the nut faste nin g th e ex hau st p ip e, remove the si l encer
CJnd exhaust pipe;
r
emove the high-t e nsion wire w ith lhe tip from the spark p lug:
r emo ve the pclrol pipe from th e union of the carbure tt or float
chambe r aft er first making· sure th at the petrol cock is cl osed and
'he r ~ is no petrol lea kage;
Not c. To remove lhc righl-hand cylinder l1 ea d, fi rst detach the sidecar.
di sconned the s uction branch pipe of th e ca rbmet tor;
remove the ca rburettor with the g·askEt;
re
move lhe cylin der head cover after fi rst placin g a i.ray under
the j oint lo lake up the oil left in the cover and cy lin de r head;
remove lhe gasket of the cy li nde r h ead cove r;
u
sing a handle f1P-1119 (or sta rting pedal), tum the crankshaft
u ntil th e pisto n is at U. D.C., ~that lhe holh val ves of t he given cy-
lin de r are cl ose d;
unscrew four special nul s and r emove the cy lind er h ea d;
withd r aw the tapp et rods from th e ryli n dcr h e<1 d, a fter first mark -
i ng them so that lhey ca n be co rr ec tl y ins talled during assembiage;
check whethe r the workt ng ch amfe rs of the \'a l vcs me proper ly
l ilt ed to their sea ts, by a ltern ate ly pou rin g kero se ne int o the exh aust
an d in let ports (ch anne i s) of the cy linder head;
cl ea n th e cylinder h ead to remo ve carbon depo sits, wash out an d
th oroug hl y exami ne it. ![ n ecessary, re pair lhe cy li nder h ea d.
Re-install the cy lind er h ea d in reverse order, w ith the p iston at
U.D.C.
During asse mblage, particular ca re sh ould be take n to ensure
that the rod is proper ly in sta lled in the t appet (pu she r) nest and
that the clear ance is pro vided between th e valve end fa ce and i.he
rocker n ose, when tightening up the four special nu ts .
Failure to co mpl y with this re quirement m ay l ea d to the be nding
of th e valves or rods .
To ensure th e correct fit between the cvlind er end face and th e
e nd fac e of the cylind er h ea d, tighten the four specia l nut s in a criss-
cross ma nn er, fo llowin g which adjust th e expans ion gap as sh ow n
in
Fig. 3. Use a 0.07 mm feeler gauge to m eas ure th e gap betw ee n
the rocl;;er e nd f ace an dlh e va lve stem.
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