S&S Cycle Big Twin Oil Pump Kits - Manual (Page 9)

9
NOTE - Drill bit size is very close to hole size and may
tend to distort hole if drill is not steadied.
CAUTION - Distorting hole may cause poor thread fit
after hole is tapped.
B. Using 1 ⁄
4
-20 tap, CAREFULLY tap hole deep
enough for 1 ⁄
4
-20 allen head set screw supplied in
kit to bottom out with screw head .125" to .150"
below gear cover gasket surface. See Pictures
21 and 22. Remove tap periodically and install
set screw to check depth.
NOTE - Do not tap hole so deep that screw blocks tappet
screen oil feed passage, inadvertently restricting oil supply
to lifters and cylinder heads.
CAUTION - Restricting oil supply to cylinder heads
may cause extensive engine damage.
C. Remove oil plug and lifter screen filter assembly.
Blow air in top end supply hole directly below top
right pump mounting bolt hole to remove chips
and ensure that passage is not blocked. See
Picture 23.
WARNING - Compressed air and particles dislodged
by compressed air are potentially harmful. Wear
protective goggles when using compressed air and
always direct air stream away from yourself and
others nearby.
D. Remove 1 ⁄
4
-20 set screw, apply drop of Loctite to
threads and install to depth of .125" to .150" below
gear cover gasket surface.
E. Install S&S Oil Pump Drill Jig, part #53-0013, on
gear cover gasket surface as in Picture 24.
F. Using a .125" ( 1 ⁄
8
") drill bit drill angle hole from
passage just plugged until it breaks through pump
gasket surface. See Pictures 24 and 25. While
drilling hole, withdraw drill frequently to clear chips.
G. Remove drill jig and blow compressed air into
passage to remove chips. Note previous cautions
regarding compressed air.
6. Crankcase Modification - 1965-1969
With kits using #31-6073 body, or 1970-1972 with
kits using #31-6003 body - Drill Primary Chain Oil
Supply Hole.
NOTE - Objective of this modification is to update early
engines to meter oil to primary chain automatically through
breather gear rather than manually through metering
screw device in pump body. This update requires use of
1973-later style breather gear such as S&S #33-4239.
This gear is not included in kits #31-6260 or #31-6270
A. Install S&S Oil Pump Drill Jig, part #53-0013, on
oil pump gasket surface as in Picture 26.
Picture 23 Picture 25 Picture 24
Picture 22