Briggs & Stratton 272147 Repair Manual page 41

Honing is done with a variable speed 1/2", portable drill
and a honing fixture. A suitable honing fixture can be
made from a 2" X 8" X 16" block of wood. Use three or
four crankcase cover mounting screws and fasten
cylinder to the honing fixture.
Clamp honing fixture and cylinder securely in a vise at a
convenient work height. Place hone drive shaft in chuck
of portable drill and tighten.
Cut a wood block and place inside cylinder to prevent
hone from extending further than 3/4" to 1" (19 mm to 25
mm) below cylinder bore.
Place hone in middle of cylinder bore. Tighten adjusting
knob with finger until stones fit snugly against cylinder
wall. DO NOT FORCE. Connect drive shaft to hone. Be
sure that cylinder and hone are centered and aligned
with drive shaft and drill spindle.
Lubricate hone as recommended by hone manufacturer.
The recommended drill speed is 300 to 700 RPM
MAXIMUM and 40-60 strokes per minute. Because
cylinder bores normally wear only in the area of ring
travel, the cylinder bore will be round above and below
ring travel, Fig. 66. Start drill and, as hone spins, move it
up and down at the bottom of the cylinder bore.
Gradually increase the length of the strokes until hone
travels full length of cylinder bore, and no more than 3/4"
to 1" above cylinder bore, Fig. 66. Lubricate hone
frequently to prevent build up on stones.
As cutting tension decreases, stop hone and tighten
adjusting knob following hone manufacturer's
recommendations. Check cylinder bore frequently.
Lubricate hone as recommended by hone manufacturer.
The recommended drill speed is 300 to 700 RPM
MAXIMUM and 40-60 strokes per minute. Because
cylinder bores normally wear only in the area of ring
travel, the cylinder bore will be round above and below
ring travel, Fig. 66. Start drill and, as hone spins, move it
up and down at the bottom of the cylinder bore.
Gradually increase the length of the strokes until hone
travels full length of cylinder bore, and no more than 3/4"
to 1" above cylinder bore, Fig. 66. Lubricate hone
frequently to prevent build up on stones.
Page 36
TM
Vanguard Twin-Cylinder OHV Liquid-Cooled Engine
VECTOR
FIXTURE
WEAR
UNWORN
AREA
3/4" TO 1"
EXTREME
HONE
TRAVEL AT
FINISH
Fig. 66
As cutting tension decreases, stop hone and tighten
adjusting knob following hone manufacturer's
recommendations. Check cylinder bore frequently.
Cylinder Finish (Cross Hatch)
The finishing stones are used after the cylinder bore has
been resized to within .0015" (.04 mm) of the desired
size or when reconditioning a cylinder bore. The finishing
stones will produce the correct cross hatch necessary for
proper lubrication. The correct cross hatch angle is
approximately 45 degrees, Fig. 67.
It is recommended that the cylinder bores be
reconditioned to restore the cross hatch when new
piston rings are to be installed in a cylinder that is within
Section 4 - Engine Overhaul
MOUNTING
SCREWS
RING
TRAVEL
BORE
HONE
TRAVEL AT
START