Yamaha GP1200 Instruction

GP1200 - Rev Date 08/05/99

Factory Pipe
Bill Of Materials
Yamaha GP1200

Item Qty. Part Number Part Description

1 1 COMHOS0095 3-1/2" Silicone Coupler (2-1/2"long) (part of #13)
2 1 COMHOS0080 2" Silicone Coupler (2 1/2"long) (part of #13)
3 3 COMFAS0100 3/8"-16 x 3/4"S.S. Hex head Bolt (Hardware kit)
4 1 COMBRK0160 GP1200 Billet Head Bracket
5 3 COMFLG0080 GP1200 Billet Aluminum Flange
6 1 COMCH12001-A GP1200 Mag Headpipe
7 1 COMCH12001-B GP1200 Mag Chamber
8 1 COMCH12002-A GP1200 Center Headpipe
9 1 COMCH12002-B GP1200 Center Chamber
10 1 COMCH12003-A GP1200 PTO Headpipe
11 1 COMCH12003-B GP1200 PTO Chamber
12 1 COMCH12004-C 2 into 1 Oval Tube Stinger
13 1 COMCH12004-D 2 into 1 Funnel Stinger
14 6 COMFAS0255 1/2"x 1-3/4" S.S. Exhaust Springs (Hardware kit)
15 6 COMFAS0001 2 Hole S.S. Spring Hook (Hardware kit)
16 4 COMFAS0046 10mm x 1.25 x 30mm Flange Bolts (Hardware kit)
17 12 COMFAS0023 8mm x 1.25 x 35mm Socket Head Bolts (Hardware kit)
18 8 COMCLP0020 #32 S.S. Hose Clamp 2" (4 in Hardware kit, 4 on parts #12,13)
19 2 COMMNT0050 Lord Mount J-11729-168 (1 in Hardware kit,1 on part #11)
20 1 COMMNT0150 1-1/2"x1-3/4" Long Spacer Mount (part of #4)
21 2 COMHOS0101 4"Silicone Coupler (1-15/16"Long) (on parts #6&8)
22 1 COMHOS0111 5"Silicone Coupler (1-15/16"Long) (part of #10)
23 4 COMCLP0050 100-120 S.S. Hose Clamp (4")(2in Hardware kit,2on parts#6&8)
24 2 COMCLP0030 #88 S.S. Hose Clamp (5")(1 in Hardware kit,1 on # 10)
25 1 COMHOS00701 1-3/4"x 6" Silicone Coupler (part of #13)
26 2 COMHOS00702 1-3/4"x 4" Silicone Coupler (part of #12)
27 - - ­28 3 COMGAS0150 Graphite/Kevlar Sealing Ring (3/16"x7-1/2") (Hardware kit)
29 9 COMGAS0180 #329 Viton O-Rings (2"I.D.x2-3/8"O.D.) (On parts #6,8&10)
30 2 COMGAS0160 #238 Viton O-Rings (3-1/2"I.D.x3-3/4"O.D.) (On parts #6&8)
31 1 COMGAS0170 #246 Viton O-Ring (4-1/2"I.D.x4-3/4"O.D.) (part of #10)
32 1 COMFAS0280 3/8"-16 x 1"S.S. Hex Head Bolt (Hardware kit)
33 5 COMFAS0095 3/8"-16 S.S. Nylock Nut (4 in Hardware kit, 1 on part #11)
34 8 COMFAS0086 3/8" S.S. Flat Washer (7 in Hardware kit,1 on part #11)
35 33 COMCLP0010 #6 S.S. Hose Clamp (14 in Hardware kit)
36 1 COMASM0156 GP1200 Exit Water Manifold Assembly
37 1 COMFTG0190 GP1200 Exit Water Manifold (part of #36)
38 3 COMFTG0020 1/8"npt x 3/8" Hose Fitting (part of #36)
39-a 1 COMASM0155 GP1200 Filter Block Assembly
40* 1 COMFTG0155 GP1200 Filter Block
41* 1 COMFTG0035 Stainless Filter Screen

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42* 1 COMFTG0160 1/2" Filter Screen Holder
43* 1 COMGAS0130 #122 Buna-N O-Ring
44* 6 COMFTG0020 1/8"npt x 3/8" Hose Fitting
45 1 COMFAS0211 15" Plastic Zip Tie (Hardware kit)
46 3 COMMNT0052 Lord Mount J-11729-190 (part of #4)
47 4 COMFAS0070 3/8"S.S. Ext. Tooth Washer (3 in Hardware kit,1 on part #4)
48 1 COMHOS0010 3/8"x 7" Waterline (part of #36 )
49 2 COMHOS0020 3/8"x 8" Waterline (on parts #6 & 10)
50 2 COMHOS0025 3/8"x 9" Waterline (on parts #11 & 36)
51 1 COMHOS0040 3/8"x 12" Waterline (part of #8)
52 1 COMHOS0041 3/8"x 12-3/4" Waterline (part of #7)
53 1 COMHOS0046 3/8"x 14" Waterline (part of #9)
54 2 COMHOS0070 3/8"x 20" Waterline (part of #39)
55 1 COMHOS0071 3/8"x 24" Waterline (part of #39)
56 3 COMHOS0072 3/8"x 29" Waterline (part of #39)
57 1 COMHOS0068 3/8"x 40" Waterline (part of #36)
58 1 COMFAS0270 3/8"x 8mm S.S. Stud
59 1 COMFAS0090 3/8"-16 S.S. Nut (part of #58)
60 1 COMMNT0030 Lord Mount J-11729-177 (part of #58)
61 2 COMFTG0110 Side Squirter (Hardware kit)
62 1 COMHOS0073 3/8"x 56" Waterline (Hardware kit)
63 3 COMCRB0177 #177.5 Mikuni Main Jet (on parts #7,9 &11)
64 1 COMCLP0040 #56 S.S. Hose Clamp (part of #13)
65 1 COMCLP0085 Plastic “ P” Clamp (Hardware kit)
66 1 COMFAS0012 #10 x 1/2" S.S.Sheet Metal Screw (Hardware kit)
67 2 COMFAS0210 4" Plastic Zip Tie (Hardware kit)

*Part Of Assembly # 39

Parts Needed That Are Not Included: Rev-Limiter/Ignition Module, Oil Injection Pump Blockoff Plate.

<< CHECK CONTENTS AGAINST BILL OF MATERIALS. REPORT ANY SHORTAGES WHERE

YOU PURCHASED YOUR FACTORY PIPE.

<< READ ALL INSTRUCTIONS CAREFULLY BEFORE STARTING INSTALLATION.

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Factory Pipe

Instructions

Yamaha GP1200

This exhaust system is designed for superstock and modified engines. Because of the number
of variables involved in this type of engine:
* Factory Pipe makes no suggestions for carburetor settings.
* This system does not carry our standard 30 day performance guarantee.

This exhaust system can be difficult to install even for experienced mechanics. We suggest
having it installed by a performance watercraft shop if you do not have the technical
experience.

Special Tools Needed: 6mm Allen Wrench, 9/64", 3/8"& 1/2" Drill Bits, Drill Motor, 18" Long

Screwdriver or 1/4" Extension with 9/32" or 7mm socket and a 2 foot length of 2"x4".

Completely remove the stock exhaust system including the large hose and boot attached to the
waterbox. Retain the hose clamp on the waterbox and the stock exhaust manifold gasket, remove the
alignment pins if still in the cylinder. Remove the Styrofoam section on the left side (from the rear of the
fuel tank to the rear hull brace), this large piece can be cut into smaller chunks and installed in the rear
of the hull later. Remove the oil injection tank , the oil injection pump, oil lines and install an oil pump
block off plate. Tie a knot in the fuel tank strap and reattach to the hull.

Note: Remove the flame arrestor(s) and throttle cable bracket to aid installation.

Install a Riva Yamaha Rev-Limiter/Ignition Module (Not Supplied) into the electrical box as per their
instructions (We suggest using the FPP or Mod-1 timing curve). Set the RPM rev limit (Ltd or
Superstock 7600-7800 RPM is suggested).

Install one each of the graphite/kevlar sealing ring (item #28) against the lip in the sleeve end of the
billet aluminum flanges (item #5). Install the billet aluminum flanges using the stock gasket with the 8mm
x 35mm hex socket bolts (item #17) and the 2 hole spring hooks (item #15) on the upper two bolts on
the PTO flange, upper/front and lower/rear on the MAG and CTR flanges. Apply Loctite and torque
to 22ft. lbs (See Fig.1).

Move the stock pump waterline to the right side below the carburetors and attach the filter block
assembly (Item # 39-B) to the end and secure with the original hose clamp. Secure the filter block to
the hull near the motor mount using the plastic “P” clamp and #10 x ½" stainless screw (items #64&65)
(See Fig.2). Attach the three front waterlines from the filter (marked “to MAG/CTR/PTO flange”) to
each of the 3/8" fittings on the flanges and secure with #6 hose clamps (item #35).

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GP1200 - Rev Date 08/05/99

Never use grease or oil on silicone couplers. Use only glass cleaner or water with dish soap if
required.

Slide a #32 hose clamp (item# 18) over the 2" coupler on the end of the 2 into 1 funnel tube stinger
(item#13). Slide the end of the 2 into 1 oval tube stinger (item#12) into the coupler, do not tighten
clamp at this time (See Fig. 3). Slip two #32 clamps over the 1 3/4" x 5" & 7" couplers on the oval
stinger tube and leave loose. Slide the complete assembly into the hull and attach the large end of the
funnel stinger with the 3-1/2" silicone coupler to the waterbox and secure with the stock hose clamp
(see Fig. 4). Now position the oval tube stinger so that there is 1/4" clearance between the 1-3/4"x 5"
coupler and the hull and fuel tank where the 1-3/4" tubes point upward. Secure the #32 hose clamp on
the 2 into1 oval stinger.

Apply a small amount of grease to the # 329 O-rings on all three headpipes. Install the center headpipe
(item# 8) into the center flange on the cylinder and install two exhaust springs (item #14). Attach the
3/8" warterline from the filter block assembly marked “to center headpipe” to the top fitting on the
center headpipe (see Fig. 5).

Temporarily slip the PTO headpipe (item# 10) from the rear compartment through the large oval hole in
hull above the stinger. Rotate the end towards the bottom of hull and then turn up into the PTO flange.
Lift up on the headpipe so that there is a 1/4" between the pipe and top of the oval hole. Put a pencil
through the mounting bracket hole of the headpipe and mark a spot on the hull to drill a 3/8" hole (see
Fig.6). Remove the headpipe and drill the 3/8" hole. Install one of the #168 lord mounts (item# 19)
through the hole from the rear and loosely secure with the 3/8" nylock nut & 3/8" flat washer (items #
33,34). Reinstall the PTO headpipe into the flange and put lord mount stud through headpipe mounting
bracket. Secure the lord mount hardware that was left loose. Secure the headpipe mounting bracket to
the lord mount with a 3/8" nylock nut & washer. Attach two exhaust springs from the PTO headpipe to
the flange. Attach the 3/8" waterline from the filter block assembly marked “to PTO headpipe” to the
top fitting on the headpipe. Secure with a #6 hose clamp.

Install the MAG headpipe into the front flange and retain with two exhaust springs. Attach the 3/8"
waterline from the filter block assembly marked “to MAG headpipe” to the top fitting on the headpipe.
Secure with a #6 hose clamp. Slip the two remaining #100-120 hose clamps over the mag and center
headpipe couplers and leave very loose. All three headpipes should now be installed in the flanges and
connected to the waterlines (see Fig. 7).

Note: You may follow the instructions below for placement of the side squirters or locate them
to suit your application.

Remove the stock side squirter on the left side below the bond line and install the aluminum side squirter

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(item # 61) in place and reattach the stock waterline with a 4" zip tie (item #67). Find a suitable spot for
the other side squirter (next to stock position or right side of hull or rear of hull above tow hook).
Attach one end of the 3/8"x 56" waterline (item# 62) and secure with #6 hose clamp. The remaining
waterline ends will be attached later.

Spray glass cleaner or water on both ends of the center chamber (item #9), the silicone coupler & O­ring on the center headpipe and the 1-3/4"x 7" coupler on the oval stinger. Slide a #100-120 hose
clamp (item# 23) over the center headpipe silicone coupler and leave loose . Slip the center chamber
into both of the lubricated couplers (a small screwdriver may help to lift the coupler over the pipe).
Make sure the chamber is fully inserted into the silicone coupler (see Fig. 8). Lightly tighten the #100­120 hose clamp (access the clamp with a long screwdriver or 9/32"/ 7mm socket on long 1/4"
extension thru the oval opening at rear or under chamber from front of engine). Slide the cylinder head
bracket (item# 4) between the cylinder head and the center chamber mounting brackets. Lightly secure
with 2 of the 10 x 30mm bolts to the cylinder head. Adjust the height of the 1 3/4" x 7" coupler on the
oval stinger until the mounting brackets align with the lord mounts in the cylinder head bracket. Once
aligned, fully secure the #100-120 & # 32 hose clamps. Remove the cylinder head bracket. Attach the
3/8" x 8" waterline from the center headpipe to the barbed fitting on the center chamber. Secure with a
# 6 hose clamp.

Remove the only long 8mm bolt from the right side of the front engine cover and install the 3/8"x 8mm
stud assembly (item # 58) use loctite on 3/8" end (see Fig. 11).

Spray glass cleaner on both ends of the MAG chamber (item #6) and the silicone coupler & o-ring on
the MAG headpipe and the 1-3/4" x 5" coupler on the oval stinger. Slide a #100-120 hose clamp
(item# 23) over the mag headpipe silicone coupler and leave loose. Install the chamber into the coupler
on the headpipe (this is a tough one! It helps to wedge a piece of 2"x4" under the mag headpipe to lift
it up -see Fig. 12). Then rotate the chamber until you can slip the mounting bracket over the lord mount
stud. Loosely attach the 3/8" nylock nut and washer to hold the chamber on the lord mount. Make sure
the chamber is fully inserted into the silicone coupler on the headpipe (see Fig.8). Then slip the mag
chamber stinger end into the 1/ 3/4" x 5" coupler and secure the #100-120 & #32 hose clamps and the
hardware that was left loose on the lord mount. Attach the 3/8" x 8" waterline from the mag headpipe
to the barbed fitting on the mag chamber and secure with a #6 hose clamp.

Install the cylinder head bracket (item# 4) on the cylinder head with the four 10mm x 30mm bolts (item
#16). Use Loctite and torque to 29ft. lbs (see Fig 10). Secure the center and mag chamber brackets to
the cylinder head bracket lord mounts with three of the 3/8"x 3/4" bolts & 3/8" lock and flat washers
(items #3,34,47). Do not use loctite on any hardware for the rubber lord mounts.

Reinstall the throttle bracket, cables and flame arrestor(s). Attach the remaining end of the stock 3/8"
black waterline from the side squirter to the front cylinder head fitting and secure with a zip tie (item#

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GP1200 - Rev Date 08/05/99

67). Attach the remaining end of the 56" waterline from the other side squirter to the rear cylinder head
fitting and secure with a # 6 hose clamp. Route the 56" waterline as needed depending on your side
squirter location (see Fig 13).

Using the supplied template drill a 3/8" hole in the rear top deck to the left and forward of the grab
handle. Slip the remaining #88 clamp over the PTO headpipe coupler. Install the PTO chamber into the
coupler while inserting the lord mount in the drilled hole. Secure the lord mount using a 3/8" nylock nut
and flat washer. Make sure the chamber is fully inserted into the silicone coupler on the headpipe (see
Fig. 8) and secure the #88 hose clamp.

Slide the open end of the 1-3/4"x 8" silicone coupler on the 2 into 1 funnel stinger over the stinger end
of the PTO chamber and secure with the remaining #32 hose clamp (see Fig 14). Attach the 3/8" x 8"
waterline from the PTO headpipe to the barbed fitting on the PTO chamber and secure with a #6 hose
clamp, Attach the 3/8" x 9" waterline from the exit water manifold (item# 37) to the barbed fitting on
the mag chamber and 3/8" x 7" waterline to the center chamber. Secure both with a #6 hose clamp (see
Fig 15). Route the remaining 40" from the exit water manifold through the oval hole in the hull and
attach to the barbed fitting on the PTO chamber and secure with a #6 hose clamp. Attach the stock
15mm black outlet waterline to the remaining fitting on the exit water manifold and secure with the stock
hose clamp. Secure the exit water manifold with the 15" plastic zip tie (Item #45) to the cylinder head
bracket. Double Check All Clamps and Fasteners.

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