S&S Cycle Big Twin Oil Pump Kits - Manual (Page 6)

6
CAUTION - Improper oil pump installation due to
incorrect identification of crankcase year group may
result in engine damage.
2. Crankcase Modification - 1970-1972 Only
Plug 3/16” Oil Overflow Hole.
A. If engine has been removed from chassis,
CAREFULLY enlarge hole in Picture 8 with .203”
(
13 ⁄
64
”) drill. If engine has not been disassembled
apply grease to bit and both ends of hole to catch
chips Wrap masking tape around drill .225” from
drill point to use as depth guide. If engine is in
chassis, enlarging hole may be difficult. In this case
hole may be tapped without enlarging, but extreme
caution is required to avoid breaking tap off in hole.
NOTE - Drill bit outside diameter 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 set screw provided with kit to rest flush
with or slightly below gasket surface. Use straight
edge to confirm set screw does not protrude above
gasket surface. See Pictures 9 and 10. If
necessary, reapply grease to both sides of hole
before inserting
1 ⁄
4
-20 tap.
NOTE - Do not tap hole so deep that screw can be
threaded completely through hole. Objective is to have
screw tighten in threads just as it becomes flush with or
slightly below oil pump gasket surface.
C. Install 1 ⁄
4
-20 set screw using Loctite on threads.
3. Crankcase Modification - 1970-1980 Only
Drill Pressure Valve Relief Hole.
A. Install S&S Oil Pump Drill Jig, part #53-0013, or
H-D Crankcase Oil Passage Drilling Jig, part
#94461-81 or #94461-82, on oil pump gasket
surface of crankcase.
Picture 11 Picture 13 Picture 12
Picture 8 Picture 10 Picture 9