Engine Reconditioning; Dismantling And Assembling The Engine; Removal And Installation Of The Cylinder Head - Dnepr MT9 Repair Manual

IV. ENGINE RECONDITIONING
1.
DISMANTLING AND
ASSEMBLI~o-'I'HE
ENGINE
Removal and Installation of the Cylinder Head
To remove the cy linder head from the engine, procee d as fol -
:ows:
ease off the nuts of t he front stud securing the en g in e;
unscr ew the nut faste nin g th e ex haus t p ip e, remove the si lencer
CJnd exhaust pipe;
remove the high-tension wi re w ith lhe t ip from the spark p lu g:
r emove the pclrol pipe from th e union of t he carburett or float
chambe r a ft er first making· sure th at the petrol cock is c losed and
'he r~
is no petrol lea kage;
Not c. To remove lhc rig hl -hand cylind er l1ea d, fi rs t detach th e sidecar.
di sconned the s uction branch pipe of th e ca rbmet tor;
remove the ca rburettor with the g·askEt ;
remove lhe cyl in der head cover after fi rs t placin g a i.ray under
the joint lo lake
up
the oil left in th e cover a n d cy linde r head;
remove lhe gasket of th e cy li nde r head cove r;
using a handle f1P -1119 (or sta rting pedal), tu m the crankshaft
until the piston is at U. D.C. ,
~that
lh e ho lh va lves of t he given cy-
li n de r a re c lose d ;
unscrew four s pecial nuls and remove th e cy lind er hea d ;
withd raw t he tapp et rods from th e ryli n dcr he<1 d, a fter first mark -
ing them so that lhey ca n be co rrectl y in stalled during assembiage;
check whethe r the wo rkt ng ch amfe rs of the \'a lvcs me proper ly
l ilted to their sea ts, by a ltern ately pou rin g kerosene int o the ex haust
an d in let ports (c hanneis) of the cylinder head;
c lea n th e cy lind er head to remove carbon depos it s , wash out an d
thoroughl y exami ne it.
![
n ecessary, re pair lhe cy li nder h ea d.
Re-install the cy lind e r hea d in reverse ord er, w ith the p is ton at
U.D.C.
During asse mblage, particular ca re s hould be take n to ensure
that the rod is proper ly in sta lled in the tappet (pu s he r) nest and
that th e c lea r ance is pro vided between the valve end fa ce and i.he
roc ker nose, when tightening up the four special nu ts .
Failure to co mpl y w ith thi s requirement m ay lea d to the bending
of th e valves or rods .
To ensure th e correct fit between the cvl ind er end face and th e
end fac e of the cylind er hea d, tighten the four specia l nuts in a criss-
cross ma nn er, fo llowin g which adjust th e expans ion gap as s how n
in Fig. 3. Use a 0.07 mm feeler gauge to m eas ure the gap between
the rocl;;er end face an dlh e va lve s tem.
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