Generac Power Systems GTV99O Service Manual page 47

SECTION l0: CYUNDER & CRANKCASE COVER
SECTION CONTENTS
......................................PAGE
cRANKCASE..........................................._.__..._.............
t0-1
Check Crankcase ............--...................................... 1 0-1
Resizing
..................................................................10-1
Cy|inderFinish........................................................1G2
Cleaninq,,,..-.---...................,,.,,,,,,,,,,,.,.,..,................ 10-2
BEAR1NGs..............._.._.......................
. .........1G2
Check Mag Bearing -..-.................--..---....................
1o-2
Remove Mag Bearing .-.--.....-..---...---........................
10-3
Innall Mag Bea ng .........
__.............__....____._..............
I0-3
Check PTO 8eadn9s .............................-.-..-.............
104
Remove/lnstall
PTO 8eaf in9.........................__...........
t0-4
Instali PTo oil Seal ..................................................
10-4
Check Camshaft 8earin9s...........................-............ 104
Oil Seals ..................................................................
10-4
CHECK CRANKCASE
Check crankcase for cracks, stripped threads or broken fins.
Check cylinder bores fof dar.age orscoring.
l.Check cylinder head mounting surfacefor distortion with a
straight edge, Figu€ 10-1.
lf mounting surfaces are distorted more than.004' (0.1
mm), the crankcase mun be rcplaced.
NOTE: ff qlinder borcs arc within srycification and show
no signs of scoaing ot other damage. new piston ings
may be installed Wviding the .ylinder bores arc rc<on-
ditioned using a igid hone with tinishing stones, to
rcstote the prcpet (oss hakh angle in the .ylinder botet The
proper cylinder cross hakh ensurcs Noper lubicatjon ahd
piston nng hrcak in.
Refer to 'Cylinder Finish (C ross Hatch)" below for correct pro-
cedure for installing cross hatch.
TOP
BOTTOIV
Figurc 10-3. Measute at Six PoinB
RESZING:
Note: Ovefsize kits are NOT available. DO NOT borc
.ylinden
CYLINDER
FIN SH (CROSS
HAICH):
Finishing nones are used when reconditioning a cylinder
bore. Thefinishing stones will produce the correct cross hatch
necessaryfor proper lubrication. The cor€ct cross hatch angle
is approximately 45 degrees, Figure 10-4.
Figute 10-1. Che*ing Cylindet Head Mounting Surtace
2.Check cylinder bores for wear using telescoping 9au9e and
dialcaliper
Standard Borc Size: 90,00-90,025 nn (3.:A3-3.51U")
a. Measure cylinder bore in 6 points at right:ngles as shown,
Figures I0-2 and 10-3.
b.lf cylinder bore is worn more than .003' (0.075 mm) or
more than .0015' (0.035 mm)out of round, ft must be
reptaceo.
Figurc 10-Z Che& Cylindet Boft
1 0 1