Shindaiwa 300 User manual

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sERVICE
MANUAL
Shindaiwa
Chain Saws
sh i ndaiwa

Service Manual
Shindaiwa Chain Saws
\.
Contents Section
page
Model Designation and Identification .. 3
2 Troubleshooting . ................... ... .... 6
3 Carburetors
.. . 22
Operation . ...... 22
Adjustment. . .. . .. . .. 24
Servicing ... .... ....... ... ... ............. ... . .. . .. 27
4 Recoil Starters . . ... . 40
5 Ignition Systems . ......
46
Troubleshooting . . .. ... ..... ... .. ..
.. 49
6 Clutches
... ... . . . ...... .. . 60
7 Cylinders and Pistons ............. .. . ... ... ... 70
8 Engine Crankcase ......... .. . .. ..80
9 Mufflers ....... 92
10 Chain Brakes . .
.. 98
11 Oil Pumps . 108
12 Rear Handles and AJV Cushions ........ 114
13 Model 357 Top Handle Saw ... 118
14 Appendix
.. 128
Speclfications
.... ... .. ....... ... .. ..
.
.. 128
To r que Values . . ... ..... 130
Metric Conversions ............ . .
.... 131
To lerances and Wear Lim it s ...... .. ..... .... 132
Fuel
and O il . .
... 134
Special Service
To ols . . ... 136
~ Shindaiw Inc. 1995

Attention Statements
Throughout this manual are statements
surrounded by boxes and preceded by
special symbols
AWARNING!
A stalement preceded by lhe word
"WAR NI NG " contains information ¡hat
shoul be acted upon
to prevenl serious
bodlly Injury.
o ATT ENTI ON!
A statement preceded by the word
"A
TIE NTI O N" contains in ormation that
should
be acted upon to avoid damaging
the
saw
Addilional stalements lhat are no ! preceded
by symbols are:
IMPORTAN T!
A slalemel lt preceded by "IMPORTANT" IS
one lhal possesses special significance.
2 e IHnda'wi'l Ine. 1995
)

Model Designation and Identificat ion Section 1
Specllicallons iJ . ~Cl ; o c~a~ge \' lllhoulncll"
Chain Saws
't"lodeI300
Mode/300S
Model360
M del377
9 S hmdaiwa I l1e . 1995 3

Section 1 Model Designation and Identification
Speclf,callOns sub¡eCIIC c"anQ" <,' 1IIoul noll:e
Chain Saws
MOcle/488
Model575 (680 and 695 similar)
Mode/577
e Shlfldaiwa ¡ne , ' 5
4

Model Designation and Identif i cat ion Section 1
SpeCilicalions subjecll hange wilh u ~otlce
Chain Saws
lode/757
shindaiWa
Mode/357
e Sh,nd~,\·)a lroe . 1995 5

Section 2 Troubles hooti ng The 2-Stroke Cycle Engine
Theory 01
Operation
Figures 2. 1 and 2 2
A two-stroke cycle or
"two-cycle" engine
produces one
power
stroke for every
revolution
of its
crankshaft. Intake
and compression
occur during the
piston's "up" stroke;
power and exhaust
occur during the
"down" stroke.
Six distinct pro-
cesses occur during
every revolution
of
the crankshaft, and a
1055 or weakness of
even one of these
processes wi/l affect
the other five.
Piston Ported Induction
1. Intake
A.SIhe piston moves up towar the c yl lnder
head a low pressu
re (vacuum) is created In
the crankcase. As the movlng pistan uncovers
he i ltake por t, atmosphenc pr es su re pushes
a fresh charge
01 fuel-air nixture in ta the
crankcase.
The
mi xture accomp1 is hes two functions
befare il is moved
to he combu sti on chamber:
•
Oi 1 su spended in lhe mi xt ure coats all
Internal engine parts
in cludlng cylmder
walls crankshaft. and bearings.
• T
he atomlzed fue l mi xture absorbs hea! as
il enters !he crankcase. lowerlng lhe
engine's opera
ti ng temperalu re .
2. Compression
As t he piston continues lo move upward and
cover lhe cylind
er ports, the combust lo n
c
ha mb er is sealed and compression begins
The ajr-fu el mi xture introduced duri ng Ihe
previous rev olution's lfans/er cycle is now
t
ra pped and becomes compressed between
Ihe piston and cy
li nder head
3.lgnition
As the piston a proaches the lap t Ihe
cylind
er , lhe spark pl ug fi res and gnl es lhe
fu el -air mi xture. To compensale lar increases
in eng
in e rpm. spar k liming is advanced
electr
on ical1y.
Spark plug
Intake
port
open
Vacuum
F/9ure Z 1 Crankcase vac m;8 creat ed dunng Ihe
compression stroke When Ihe spark
plllg (¡res ¡he
compressed mixture al>nve l/ le Dlston ¡gil/les and
begms ro e ano
Shlndaiwa Inc 1995
6

Troubleshooting The 2-Stroke Cycle Engine Section 2
4. Power (combustion)
T he fuel-air mi xture xpands rapldly as il
burns, forclng
he plston dawn he cytlr de r.
Pistan movement is transferred to tlle eran -
shaft thraugh
the cannecting rad rotatmg ti e
crankshalt.
5. Exhaust
Exp an Ing gas es contlnue t fa ce Ihe pistan
downward, exposlng
the exhaus! port Mas! of
the spent combustlOn gasse are expelled
through the exhaust port
6. Transfer
The plston's downward movemel l c;overs tI'le
Intake port and un covers the transler por!
hile simultaneously compressing
the res h
fuel - ai r mi xture drawn into the crankcase
during S ep 1,
As th e ¡ransler porl is uncov-
ered, the f esh mi ture
sWlfls rapidly Irlto tlle
cylinder
As the Iresh fuel-alr m xture nters he
cylinder It al so helps to oush or scavengeany FIgW8 ? 2 Ttle burning mixture expands for ing 1/)",
remalning exhaust gasses out througn the
oistun down and comp r essmg ¡he Iresh r71l~tllf 1I the
cr3nkcas ' As Ihe plston exposes lile tlansfer por
exhaust porL
crankcase pressure {orces rresh mixture ¡neo the
combustlon chamber and Ilelps pus/] 'he remamine
8\haust gasses fhroug/l t he exhausf port ____ _
7

Section 2 Troubleshooting Th e 2- Str oke Cycle E ng ine
Theory of Reed Valve Induction
Operation
as used on Model 357
Fi gures 2.3 and 2.4
1.lntake
As the piston moves up toward he cylinde r·
head, low pressure (vacuum) cre al ed in Ihe
crankcase a
ll ows almospheric p re ssure lo
open Ih e reed valve and push a fresh charge
01luel-air mix
tu re in lo the cra nk case.
The fuel
-a ir mixture acc omplishes two
lunctions before
it is moved to lhe co l bustlor
chamber
• O
il suspended in the mixtu re coa ts a ll
internal engi ne parts includ in g cylinder
wall
s, cra nk sha ft , and bearings
• The alomized fuel mixture absorbs heat
from
th e crankcas e, lowering lhe eng in e's
operating temperatur
e.
2. Compression
As the pis ton con ti nues to move upwa rd and
co ver the cy li nder ports, the co mb ustion
chamber is sealed and compression
beg ins.
The air-tuel mixture intr
oduced dur in g lhe
previous rev
ol ution's transler cycle is now
trapped and becomes compressed be ween
Ihe piston and cy
li nder head.
3. lgnition
As the pislon approaches Ihe cyl in der head.
the spark plug
ti res and ignltes lhe fuel- al r
mi
xt ur e. To co mp en sa te fo r in c re ases rn
en gine rp m, spark timing is advanced
el ectronica li y
Combustion and Exhaust and Transfer
Compression Ports
(c losed)
o
Reed Valve Open
L
ow Pressure
Fi gu re 2.3 Reed Va /v e /ndUC/IOn Syslem (reed va/ve open)
~ ) Sh'nda,wa Inc. 19 958

Troubleshooting The 2-Stroke Cycle Engine Section2
4. Power (combustion)
The fuel-alr mi xture expands rapidly as 1\
burns. forcing the pisten down tlle cyilnder
Pistan movement
IS lransferred lo the crank-
shaft through
th e cennecllng rod, rotaling tl->e
crankshaft.
5. Exhaust
Expandlng gasses continue to lor e t he pistan
down
Nard, ex posing Ihe exllaust porL Mest 01
the spent combus Ion gasses are expelled
lhrough lhe exl1aust port.
6. Transfer
The plslon's downward mevemen! om -
presses
the luel -a ir mi xture drawn inlc, the
crankcase du
rl ng Slep 1, causlng lile reed
valve lo clase,
As the movlng pisten uncovers
t
he transfer por\. the resh mi !..Ire swirls
rapioly into
the cyllnder
As th e fresh fuel-air mi lure enters he
cylinder. 1I also helps o pusl, ar scavenge any
rem ai ning exha st gasses out through t he
ex hausl port
Exhaust Port
(ope n)
Reed Valve
Closed
Figure 2.4 Reeo Va/ve /nduCltOn Syslem (reel ' va/ve e/oseo)
9

Section 2 Troubleshooting
General Mechanlc
al failure 01 any carburelar 15 lar less IMPORTANT!
C OIn an thnn prablems arising ¡rom contami-
Tr oubleshooting Carbu
re tor operation is directly affecled by
nated fuel, imp
ro per adJus tm ent. ar operator
Procedures
~he quallly of a ir an uel entenng he
abuse. Figure 2
.5 is pro ided as a t rou bl e-
carburelar! Before troubleshooting r
shooting checklls
t.
adjusting any carburet
or, Inspect fuel and
alr 1¡lle
rs for cleanliness, operalion and
proper tnstallati
on !
1.
15 the fuel tan k fil le d
Ith clean, 5 Are the spark arrestor and murf1er 8. Inspect the tan k ventoCle an 0 1'
fr es h fuel 01 the praper gra e an d clean and properly installed? replace as requtred
mi xt ure? 6. I
n5 pect fuel fi ller and check f el 9. Reset carburetm
mi ture
2. Check for spark! Ilnes f r leaks/deterioratlan dJustments
(S ectian 3).
Pressure-test
fu el system for leaks
3. Compressian at least
100 psi al' 10. Pressure test the carburetor for
abo
e?
7.
Ins eco the Impulse tube al' pop-otf and reseat values
passage
fo r candltion and
4.
Is the ai r filter clean and pr op erly operatron P
re ssure-tesl crankcase
installe ?
as require
Figure 2 5 Troubleshoollng Guide
10 e
Sh IlOrJa" .'i a Ir. I 95

Troubleshooting Se ction 2
1, Fuel
Drain all I
el into a clean container an
Adjustable-gap
Te ster
discard any fuel showing visible contamlnation
such as d
lr l or wa er Be especl8l ly suspicious
01 fuel with an unusual odor, cioudiness, or
thickening. II he fuel is severly contaminated
or "varnislled " lhe carburetor and fuel system
musl be completely ciisassemblecl f
or a
thorough inspectlon and cleaning. For speciftc
fuel recommendations and testm procedures,
see "
Fuel and Oil in the Appendix
2. Spark (Figure 2. 7)
Connect the spark plug lead to an ad)ustab le -
gap spark tester, lurn ¡he ig nltion wltch t lhe ~
1" (on) positlon and cr an k the engine vigor ~
ousl o tes lor spark A healthy Ignit io n Figure 2. 7 Checking Spark
should produce a strong billa spark 01 nearly
1/4" le nglh at tlle lester. II no spark IS viS ible
or il lhe spark is weak or yellow in color refer Minimum
10 0 psi
lo
"I gnition Trouble hootlng." (Secllon 5)
3. Compression (Figure 2.8)
Install a reliab
le compression gauge and lhen
crank the engine vigorously lhrough 2-3 pulls
01 the r ecod starter, Compressior al cra nki ng
speeds should be
al lea si 100 PSI or above.
Compresion readings consistently below 100
psi can indicate inter
na l engine wear or
damage (Sectlons 7 and
8)
4. Air Filter
Inspect the ai r fi ter alld clean or replace fr lter
elements as requireo (Figu
re 29) .
• Paper-type elements should be cleaned FIgure
:} 8 Checkmg Compression
with campressed air ollly
•
AII a ha r Shindaiwa li l er elements can e Filt
er Element; Cle an
washed
in clean fuel mi ture and lhen with fuel mix
tu re
blown dry befare reinstallattan
o AITENTION!
Careless use or com pr essed alr can
damage air filler elements. Always direct
lhe airstream I
ram Ihe Inslde (carburetar
slde) toward the oulside iace o lhe
element Any engine ¡hat has been rur
wilh a damage
or inc or rectly installed alr
filter assemb
ly should e arelully
inspecled lar Internal damag Irom
ingested deb
ns
F,g¡¡ re ? 9 5 77 AIf Fllter Installation
11

Section 2 Troubleshooting
General
Troubleshoot ing
Procedures
(contlnued)
5. Spark Arrestor Screen and Exhaust Port
(Cigures 2 10 alld _11 )
Remove and .nspect ¡he soarK arres!r'r
scceel1
and clean a- required. II lurt1ler
decarbonizlng If n cess~ rV rler o Sectíol1 9
(Mufflers) and Sectlon 1 (Plstorrsl
IMPORTANT!
A cloggecl arrpstor sereen or mufflel can
cause an engine lo lose power. and ,Tlay
prevenllhe engine tron- star In •. altogeller
l
6. Fuel Filter and Unes
Remove and mspeet the fue Trlle r elernellls
and screens.
Be espec.al valen ror al"iy slgns
of dir! water
01 oll1er contan1mallon
(FigurQ 2 12)
IMPORTANT!
Olr' .)f othe! ciebris rJl" Ihe inner [JI Br screel1
may incllcate aciclilional deb"ls IS
trappeo
withir lile carbUlptr)r I)oclyl Trappea deb, iS
ral reslriet fuel flow posslbly le(;l(jlng to
Anglne s 17ure
l
Tug gently Oll the luellm an("1 ¡eplace any
me showlng unusual s retch or 105s o elaslíc
ity. Be especlally ler tor sullened seclons 01
Irne that mighl callarse linder sllclion a 1rl
"slarve the saw
Dlsconnect lhe fuel Ilr.c fro~ l l the ca!buretol
Plug or clamp the trlt r end ni he lino i1nd use
Shlndalwa p/n 99909-93 to pressure
ec;t he
Ilne far ledks (Figure 2 13)
IMPORTANT!
Wher servicing fuel flllers always use lile
lactory"rf'comrnendect fllter or components
lor lile specific model cárburetor dnu
appiication
l ModlÍlcatlor subst
tutlor. or
lIse
01 aftermarket fuel fltt8rs ar omponents
can ur balance fue' ¡lO,"", w ti in Ihe Gl1tlr
syslem causing 8,'gne performat ce
problems
l
Fg 111" ) 1(; Inspecl Arrt'stur ~creen {.b:- sno~ IlJ
Carb on B uil d up
Look through
on Exhausl Port
the spark
pl ug hole
Spark Pl
ug
Ho le
Ft ,,/(f.J? 71 Inspec: E\'l1dUSI eor' lor (:albllll Builduo
Body -.........._
I nne!"
( "",
Elements Elemenl
\" -I
p
(.JO ,J ,g) R el a ""
k - ( )1 ~. . ~~L,~
, ~ ~y
" '- ( -¡... ;r'""'\
Some earl y- model Walbro filters ~-:¡..U.
used an Inner elemen! Ihal re- . ~
sembled grey wool or fell. Replace ;;-
Ihese elemenls with a pair of
melal creens, p/n 22 11 8-85460
~ y 1(<': _ . '.~ hiel FIller Elernenrs
Pr ess u re
Gauge
p/n 99909-93
12

Troubleshooting Section 2
General
Troubleshooting
Procedures
( ca nl in ued)
7. Impulse PassagelCrankcase Pressure
Test The Impulse Passage,
Models 488 and larger (Figure 2
14)
Dlscanneet 118 Impulse lube trorn Itle tuel
pump . and ..,are fu Iy Inspecl ¡he ~ut)P tal
damage or deterioratioil
Conneel pressure guage (Sllil dalwa
o/n
99909-93 or equi lalen!) lo the Impulse
lube and Ihen crank Itle engine
• A flue Jaling gauge readrng durlng crank
ing inclica¡es lhe impulse lUDe 15 clear and
IS fune!lonlng propel IV
• No needle movement rndlca es a IJlugged
Impulse t ube ar posslbly a eral' edse leak.
or
The passa:;¡e can bt;-; tested by pl;:¡cing a
small draplel fOil aver lh open end 01 lhe
mpulse lube ancl ti en cranking lile engne. II
lhe I mpulse passage is clear he 'JII drople t
will mave rapldly ir anel a 1as lhe englne is
eranked
Test The Impulse Passage, Models 300
through 377 (ineludes 357)
(figure 2.15)
Remove the earburetor and
place cl small
dr-opl
e\ 01 0 11 ver lhe Imp~llse paosage I lo le
and esl as aboye .
IMPORTANT!
Never use gaskt: sealant 011 :;¡ny gashe
installed
over an Impuls(j passage
l Gaskel
sealant ar plU9 11e impulse passage
cduSHlg the ellgln(j lo run lean
Test For Crankease Leaks
An engine wlth a rough or erratlc ,die or une
ha! IS unstaole ar .runs a vay unde!" load
may be dra IIIg extra alr HHOUgh leaklng
CranKcase seals or gas l ~ets.
• Alter bl o ck lng !he intake al1d exllallst ports
a
gauge suctl as Shlllda'Wa p/n 721 74-
99200 can be '.lsed lo pressUllze lh
crankcase lhrough ne
mpulse tul) ~ r
tlirough an adapter
35 5hown (Figure 2 16)
• 11 the correel block-off plales are 1101
avarlable the parts ( an usually I)p IJlocked
by cl amplng small serlons o' heavy rut)ber
ar ;J8skel material I lenealfl lile muftler ano
carburetor bases.
Needle
Flu cluales
•.
Rapidly
~_ .
~
. • I
=
-.
--.
~
--~- ~.
FIgure 2 1 ,,) Testing Imaulse Passage (488 ano larGer)
Pla ce oil
droplet he re .
Flrjure ..: 15 res/lilg lIJe Imptl/se
Pa"sdge (300 rhraugh 37 7)
Shindalw p/n
72174 -99200
Clamp th e
impulse
tube
Stea
dy al 4- 6 psi (about .4 kg)
hg:Jre ? IR Ledk-fesfmg ,Vitll Gauge PII1 72 74-99200
S'"f' . ¡.Id In 1 ley 13

Section 2 Trou ble s hooti ng
General
Troubleshooting
Procedures
(continued)
8. Tank Vent
In spect lhe fuel tank ven! lar damage or
c
lo gging, and clear or replace as required,
9. Carburetor Adjustments
Figu re 2, 17
Using the settmgs and justment procedures
ou lined
In Sectlon 3, rese! all carburetor
adj
us ments to factory-recommended settings,
10. Pop-off and Reseat Pressures
(metering valve)
(Figure 2 18)
Connect Shindaiwa pressure tester 9990 -93
or equivalent to the carburetor fuel inlet. and
test
th e inleL ne edle assembly for proper pop-
off and
re s ea values
•
Re seat pressure demonstr at es the
carbureto
r's ability to block and regulate
ty pical fuel pump ressur es 015- psi,
• Pop-off press Ires can ary con
si de rab Iy,
but the inle! needle mus reseal and hold
pressu
re 01a! leas! 10p SI
IMPORTANT!
F or accurate pres ure tesling, Ihe inlet
needle must be sliglllly wet with
fu el Or
salven!.
Figure 21 7 Carbure/or AdJustments (357 shown)
Sleady al 10
psi
Connecl lo
or above
fuel inlet
Fi ure 218 Testmg Pop-off and Res eal Pressure
(HOA shown)
e Shindalwa ¡ ne , 1 99::>
14

Tro ubleshooti ng Section 2
Tr oubleshooting THE ENGINE DOES NOT START
Guide What To Check Possible Cause Remedy
Ooes t
he engi ne
crank? NO Fault reeoíl starler
IFluid In lhe crankcase.
Inlernal damage .
Refer
to the Recoil Sect ion .
Re fer to the C ar buretor S ee tion
Re ter to t he Eng in e Crankcas el
VES Cylinder and
Pi st ons Sectlons
Check
compression.
Loose spark
pl u
Excess wear
on
cylinder, piston, rings. I
Tighten an d re-te st.
Re ter lo tlle Cyllnde rs and Pl stons Section
VES
18 lhe f el (resh
and 01Ihe
p
ro p er grade
and mixture?
NO
Fuel is o 1- ated
rna y also be stale.
varnlshe
or
conlaminated I
Re-lill ith fres!l fue l 01
the correet mi xture
Refer lo Fuels in
the Appendix
VES
18 fuel reaching
the earburetor?
(spray
fuel
NO Clogged fuel filter
damaged fuelline
or Im pu lse assage. I
Cle an ar replace fuel sys lem
components as
re q ui r ed.
directly inlo the
ca rb uretor
venlurI lo lest)
VES
Is Ihere s ar k al
The Ignition IMove sWllch lo " ON " an d re-start.
the spark plug
vire terminal? s
it eh IS "O FF ".
Fau l ty ig nl tlo gro n I
Fau1ty spark plug lead. Refer lo the Ig nilion Section
VES Faully Ignitlon syslem.
Is tne spark
plug firing NO Plug is soakcd wilh fuel , Cr
an k the engine with the plug removed:
replaee
the plug, and re-star .
properly?
The pl ug is fouled or is
IClean an d re gap Ihe p lu g lo O 024 "
Improperly gapped.
Plug 15 mlernally faulty IReplaee with lhe corree! plug
VES or
01 the mcorrec¡ type. (see Specifications in lhe Appendl x)
Flywheel ke y is
s he ar ed.
NO
Loose Ilywhe el ar
"tl1rown" cllaln I
Replaee the key and relorque
the flywheel ( see Torque Values in
Ihe Appendix)
VES Arreslar screen/cyllnder Clean or replace arreslor screen
system clean
and functioning
properl
y? (can
exhausI port IS elagged
wlth carbon (refer lo
he Muffler seclion).
Inspect and decarbonize exhaust
port (Cyllnder and Pistan sectian)
pr event the
englne from
firing)
e Shl!.daiwa In c. 1995 15

Se ction 2 Tro ubleshooting
LOW POWER OUTPUT
Troubleshooting
Guide
(conli nu ed) What
to Ch eck
Is the eng in e
overheating?
The
en gine
runs
ro gil al
al l speeds.
Black, soa
ty
smoke al
exh
au sl may
al
so be
unburned
fu el
al lile exhau st.
The engine
knocks under
load
P
ossib le Cause
Operator
is overworking
r---- lhe machine.
Carburetor mixture 15
loo lean.
Fuel contalns excessive
oxygenates
IncOI Tect fuellad ratio.
Flywheel/cyllnder fins
mi
ss ing or clogged
Air defleclor or cyllilder
caver mi
ss in g or
damaged
Carban deposits
In
cyllnder head or
on pistan.
C!ogged
al r cleaner
r----
Reme dy
I Sharpen lhe saw chaln
Cu t at a slower rate.
AdJust the e rburetor (Carburetor sectlon)
See also " Fuels" in lhe Appendix
I lnspecI lhe bool lar leakage.
IDraln
th e fuel syslem and reti!1 wllh lile
correet fuel mixture (see the Appendi x).
, Clea
n. re palr or replace componenls
as necessa
ry
1
Decarbonize. Refer lo lhe Pis t an an d
I Cylinder SecllOn
I Servlce Ihe alr cleaner.
Water in the fuel system, I !nspect
fue l strainer and screens.
Loase or damaged
spark plug
Choke is closed
r---- Metering needle stlcking.
Faulty carburetor
diaphragm,
Engine IS overlíeated
f--------
Impropel fuel or fuel
mixture.
Carbon deposits
in lhe
combustion chamber,
I Tlghten or replace spark p lu g as requi re d
I Open lhe choke.
I Disassemble and thoroughly clean Ihe
carburetor (s ee Carburetor sectian)
I Refer lo Overheating causes/remedies
(above)
I Check fuel octa e rating rest fo r the
presence of alcohol ar other oxygenates
in lile fuel (see Fuels In lhe Appendi x)
Decarbonize (s ee lhe Cylinder and Pistan
section)
16

Trouble s hootin g Section 2
ADDITIONAL PROBLEMS
Symptom
Poor
r----
acc eleration
Uneven idl
e;
r----
engine may "run
away" at higher
th rottle s ttings
Saw chaln
r----
moves at id le
speed
Excessive 1
--
vibration.
Possible Cause
Clogged
ai r filter.
Sp ar arrestar
(carbon deposil
s) .
C
lo gg ed fuel I ll t er.
Carburetor mixture
in corre ct ly adJusted.
Idle speed
l
oo low
Oírl, gum or v rnlsh
clogging carburetor.
Clo
gged tank ve n!.
Remedy
Clean the element.
Oecarb
on ize Refer to the Mutfl er section.
Clean/replace fuel
fi lter (Carburetor section)
Adjust carburetor (Carburetor section)
Ad
Just. Refer to the Spec ifi cations section
in the Appendix
Ove
rh aul lhe carburetar (Carburetor sechon)
Clean or replace vent
as required.
Blocked i
mp ulse passage. Inspect and pressure-test ¡ines;
Fu
elline IS collapsing.
Metering diaphragm is
lea
ki ng.
Spark ar
re star is c lo gge
Air leak al
bo ot, seal. or
c
ra nkcase.
Idle speed too hi
gh .
Broken clutch sprin
g.
Damaged
A/V cus hi on
Bent cra
nk shaf t.
Oamaged flywheel fins.
Faultv i.Qnition .
replace as required (Carburetor section).
Pressure-test the carburetor; overhaul
as
required (Carburetor section)
Clean/replace
as required ( Mu rfl er se ctio n) .
Remove and inspect boot or
in sulator block;
Pressure te
st crankcase
(C rankcase section)
Reset
id le speed to specificatíon (Appendi x)
Replace spring, shoes as re quired
(C lutch section).
See Rear Handles and Mounts secti
on .
See Crankcase section
See t
he Recoil Starters section.
See the
Iq nition sectian.
" SI indaiw8 Inc 1995 17

Section 2
roub leshooting
Di agnosing
Engine Seizure An englne can seize whenever there
is metal-
to-metal contact between Internal
mOVlr1g
parts. Mas engine s ei zures can be traced to
al leas! one al lhe tollowlng
Lubrication (Rgure 2 19)
• Lack of oi l. Insufftclent or poorly mi xed oil
ra t io . Shindalwa macl ines are designed to
use Shindalwa PrerniulTI 2-cycle Engme 0 11
at aalio of 401 (3.2 ozs./US gallon).
• Incorrect oil type. Generic-brands and
some outboard motor mlxing otls may not
p ovide sufficlent lubricallon l roughoL
.t he
br ad temperature range associated with
high performance a
lr -cooled englne
operallon,
IMPOR TA NT!
When Shindai wa Premlum 2-cycle Englne
O
il is nol available, fu el should be mlxed
wrth a premlum-graoe 2-cycle ml xlng 0 11
speciflcally deslgned lar us in high-
performance alr cooled 2-cycle enginesl
Debris (Figure 2 2 0)
• Excessive carbon buildup. Carbon
accumulations may be dislodged from the
ex haust port. jarnmi ng bel een pistan and
cylinde
r.
• Faulty or missing air filter. Oir!. water or
olher debris enters lhe crankcase and
cylinder scoring the
piS on and c l in der
an d causing rapid componenl wear
Severe metal gallingl
transfer all around the
p
is ton; even scoring
Figure 2 19
Pistoll damaged Ir m
leck 01 lubflcatlon
Carbon scoring
produces soft-
edged grooves
on the exhaust
side of the
plston. Piston
rings are still
free
in the
grooves.
Ingested debris
produces a
sandblasted
appearance or a
dull grey surface
on the intake
side of the piston
(away from the
arrow). The
piston skirt
is
worn thin at the
base. Ring lands
are worn.
Ingested water
or snow leaves
a
sh i ny,
polished area
on the intake
side (away
from the arrow)
Figure 2 20 Opemling wl th debris in the cylinder
Factors Affecting Engine Durability
A II Shindaiwa produets are powereo by high
performance engines that produce lhe most
horsepower from lhe Ilght
es t possible
deslgn
Two faeto rs are cnllcal to lhe ervlce Ilfe
an durability
01 any hlgh erformance
engine:
1. Lubrication
Proper lubricalion is essen ¡a , far reducng
[riction between an engine's movlng parls.
By redue
mg friction lubrica!ioll also
helps reduce Ihe heal de elooed
cJu ri ng
normal engine operalion
Si ce a 2-c ele englne doesn't ha ve a
reservo!r of ol/In lIs crankcase. sleady
supply of high-quallty lubrican! mus enler
the englne as part of the luel
mi xture.
Refer lo lhe Fu
el and Oil Seetion In t e
Appendlx lor speciflc luel/oll
mi xture
informatlon
2.Cooling
Cooling any high performance engine IS a
complex task.
To remove the heal generated
from both fricli
on and the combuslion
process, Shindaiwa engines re/y
011 :
• Lubricaltng O il
• Air-F el Mi xture
• Cylln
der Oesign
• Flywheel
Oes igll
ATTENTION!
Proper lubricalion and cooling are
essential
lO both th e performance and
service lite
01 an y tw o-cycle enginel A
partía/ failure
in either 01 these areas can
lead o engine seizurel
o Shlnd3'wa lroe . 199518

Tro ubleshoot in g Section 2
Over he a ting (F igure 2.21)
•
Operating an engine with clogged or
damaged cooling fins, or with missing
co oli ng sys tem components. Overheated
Internal maving parts may expand beyand
normal rates and dlmenslons,
al low in g
metal-to-metal c
ontact
IMPORTANT!
Overheat damage is olten caused by
forclng a saw englne lo cut Wllh a dull or
Impraperly
sh arpened c ha in, or by failing lo
seleel the proper
si ze and capa city saw lar
Ihe Job al hand
•
Preignition (Figure 22 2) lrom incorrecl
spark plug/carbon bulldup (may
al so res ul t
f
ro m le an ca lb urelor s el Ing)
• I
ncorrect or "lean" fuel-air ratio
(Figure 2 23 ).
Operating an engine al an oxygen-rich
carb
ur et or sett in g rai ses combustian
temperatures (same
eHe el as pre ss in g the
le
ve r on an acetylene culting torc h)
• Air Leaks
Ai r leak in g pa s! crankcase seals, c yl inder
ga skets, or impulse passages can dilule or
"leal1out" an engine's fuel-alr ralla, and can
produce
th e same elfect as an imp ro perly
adjusted carbu
re tor
•
Oxygenated fuels, any fuel containing
alcoholar ether-based oxygenating
compounds. So-called "clean air" fu els are
blended 10 provlde a
dd it ional oxygen
dunng the combustlon process, produc
ln g
hl
ghe r co mb us tion tempe ra tures similar lo
a
"l ean" carburetOi" adj us lm en t. For add i-
tional informatian on oxygenated fuels, refer
[O Fuel and O i/ ln th e App endi x.
• Outdated or low-octane fuel can burn
uneven
ly producing excessive combus ti on
pressu
re s lhat tend lo have a hammering
effect
on pistons and re la le d components
(Figure 2
.2 4). Shmdal wa engines requi re a
fuel wlth an octane ratlng
01 al lea s! 7 or
aboye Unless fuel has been pretreated
wllh an approved
fue l stabil iz er su ch as
Sta
-B II TM , Shmdalwa advlses ag al n st uSlng
any motor fuel slo
re d over 30 -da ys
Overheating causes a
piston skirt to expand
and score heavily
on the
exhaust side 01 the
cylinder, and may
produce similar (but
reduced) scoring on the
cooler intake side as
well.
Figure 22 1 Oamage caus ed by overnear mg
Preignition typically
melts the piston crown
at the exhaust side
(toward the arrow) 01 the
piston, or may burn a
hole completely through
the crown. Heat causes
the piston to expand and
score at the exhaust
side, sticking rings
in
their grooves.
Flgvre 2.2 2 D amege caused by pr elgn l/lO n
1-1/4 1-1/8
Carburetor Adjustment
Figure 2.2 3 Exhaust Gas Temperature vs
Carburelor Aoius lmenr
Detonation results
when luel explodes
instead
01 burning,
and has a hammering
effect that can crack or
pound a hole through
a piston top.
CYL-1J
Figure 224 Damage caused by delonalion.
,. Shl ndalwa Inc 1995 19