Fuel Pump Disassembly/Assembly; Carburetor Specifications - Polaris 1999 Sportsman 400 Service Manual

FUEL SYSTEM
Disassemb ly/Assembly
NOTE
Do
11 01
disassemble the pump until
it
has bee n determ ined whe ther
ne w d iaphragms, gaskets Gild
valves are available. Contact a Po-
laris dealership.
Re fer to Figure
HO .
1. Rem ove the screws sec ur ing the d iaph ragm
cover
(A,
Figure
HI )
and rem o ve the cover. Note
the location of the two lon ger screws
(B,
Fi gure
HI ).
2. Rem ove the d iaph ragm cover gaske t, di a-
phragm and va lve bod y gaske t.
197
3. Re move the outlet ch eck valve co ver, dia -
phrag m and gaske t.
4 . Clean all parts in soa py water and rinse in
water. Ca re fu lly bl ow dr y
with
low pr essure
compressed air.
5. Inspect
th
e inlet an
d o ut let chec k valves for
cracks, warpage or damage.
6.
Check the diaphragms for cracks, holes or swelling.
7.
Check the sea ling surfaces o f the pump bo dy
and both covers .
8. Replace gas ke ts and d iaphragm s as com-
plet e se ts .
9.
Reassembl e the pump in the reverse or de r of
disassembl y. Tig hte n all screws securely.
I tem
Table 1 CARBURETOR SPECIFICATIONS
1996·1998 1999 and later
Carb ureto r
Manufacturer
Type
Main jet
Pilot j et
Pilot air jet
Jet needle and E-clip position
Nee dle jet
Throttle valve
Pilot screw
1996-1997
1998
Float heig ht
Idte speed
Mikuni CV
BST 34
142.5
42.5
160
5078·3
P-l
100
1 1(2 turns out
2 turns out
13.0
mm
(0.51 In.)
1100·1300 rpm
Mikun i CV
BTS34
155
40
160
4HB41·3
Y-O
0 -0
2518
turns ou t
13.0
mm
(0.51
in.)
1000-1400 rpm