"Signature Series" Seadoo â GSX/GTX 951 Limited Exhaust System

(PN SSB951G) 

Installation Instructions 

PLEASE READ ALL INSTRUCTIONS, WARRANTY & DISCLAIMER PRIOR TO INSTALLING! 

Parts Included:

Pipe components:

1ea. expansion chamber 1ea. Exhaust Flange

1ea. 3"OD x 1 3/8" silicone Hose 1ea. 1/2" OD x 5" Waterline

2ea. 1/4" OD x 22" Waterline 1ea. 3/8 OD x 5" Waterline

1ea. 3/8" x 3/8" x 1/4" Nylon "T" Fitting 2ea. 70-90 Norma Clamps

2ea. 1/2" Clamps 8ea. Zip Ties

1 ea. Exhaust Flange Gasket 1ea. 1/8" Brass Pipe Plug

Water Injection components:

1ea. Micro-Touch Water Controller 1ea. Solenoid

1ea. Weather Pack Connector 2ea. Female Electrical Connectors

2ea. Rubber Seals 1ea. 1/8" x 1/4" Straight Brass Fitting

1ea. 1/8 x 3/8 Straight Brass Fitting

Misc.

Template for hull modification Warranty

Decals & Instructions 

Installation Instructions 

1. Remove stock exhaust system, leaving exhaust manifold and stock waterbox hose in place.

2. Clean exhaust manifold gasket surface good. (Very Important)

3. Take the stock 1/2" waterline that was connected between the stock expansion chamber and then ran out the boat, and run this line under the motor to the right side of the hull. (so instead of it being on the front of the motor, it will then be on the RIGHT side of the motor)

4. Take and install the new head pipe gasket (supplied) onto the exhaust manifold (no sealant required as these gaskets are pre-dipped for sealing)

5. At this time, if you are installing on a GSX, you will want to modify the lip on the hull. To do this, we reccommend covering the motor compartment with a large towel, etc. to prevent any shavings entering motor compartment.

Place the template on the carb side of the ski on the fiberglass lip (like diagram) centering the edge of the template to the center of the exhaust port like diagram illustrates.We reccommend cutting with a file or a rotary grinder (for best results)

6. Loosen the 3ea. 8mm bolts that hold the front stock exhaust mounting bracket.

7. Remove the stock exhaust bracket on the RIGHT side of the engine.

8. Install the 3" x 1 3/8" silicone hose onto the chamber body. Slide the flange onto the opposite end of the silicone hose.

9. Slide the chamber into the hull, and align chamber body to the stock waterbox hose leading to waterbox and exhaust manifold. Center the exhaust mounting bracket. Install all 10mm bolts to 28 ft. pounds, and 8mm bolts to 22 ft. pounds.

10. Install the 2ea. 70-90 Norma clamps onto silicone hose and tighten.

Make sure these clamps are straight, and do not over tighten. Make sure you tighten the clamps on the hose leading to waterbox. 

Waterline Installation (Please refer to diagram) 

1. Take the 1/2" x 5" waterline (supplied) and run from the 1/2" 90 degree brass fitting on flange to the 1/2" 90 degree brass fitting on top of the expansion chamber. Tighten with supplied 1/2" clamps.

2. Take the stock 1/2" waterline that you installed underneath the motor to the right hand side of the boat and hook up to the 1/2" 90 degree brass fitting on the bottom of pipe and tighten with stock clamp.

3. Take the stock 1/4" water bypass line and hook up to the straight 1/4" brass fitting on the flange and zip tie secure. IMPORTANT...You will only be running 1 of the 1/4' bypass lines. Make sure you plug the second line!! THIS IS EXTREMELY IMPORTANT AS WATER WILL FILL YOUR HULL UNLESS THIS PROCESS IS COMPLETED!

4. Remove the water valve on the top of the waterbox and the waterline connected to it from the hull. Plug this hole with 1/8" pipe plug (supplied).

5. Make sure that your water flow coming in from the pump, is the same as our instructions. We have found on some Seadoo's â that this is reversed. VERY IMPORTANT! 

Water Injection Installation 

IMPORTANT NOTE: The following steps 1 through 2 should be assembled prior to installing on hard parts. This will make it much easier to secure later. Please refer to waterline diagram for guidance. 

1. On the stock 1/2" incoming waterline, there is a 1/2" T. You will hook up the waterlines starting from this point.

2. Referring to diagram, lay out your waterlines and solenoid. Secure ALL lines in place with zipties on each side of waterlines.

VERY IMPORTANT Make sure that the solenoid "in" and "out" are installed in the correct direction!!!

Go back and make sure that each line is secure before proceeding to the next step.

3. Locate a desired location for the Micro-touch Module to secure MAKING SURE that it is not located next to the coils!! Secure in place by either using zip ties or double sided sticky tape, etc.

4. The RED wire connects to the positive on the battery.

5. The BLACK wire connects to the NEGATIVE on the battery.

6. The BROWN wire does not hook up to anything.

7. The YELLOW wire should be wrapped around the spark plug wire at least 3 times, and secured. (On the 1999 models you will need to wrap this yellow wire around BOTH spark plugs 3 times)

8. Hook up the weather pack connector assembly to solenoid.

9. Plug in the Micro-Touch module to solenoid.

10. Preset module to 2000 "On" and 6750 "Off". Or 2000 "On" and 6400 "Off". On a completely bone stock boat, the 6750 seems to work the best. If you utilize an aftermarket head, etc., the 6400 setting for "off" seems to work better. 

AFTERMARKET REV LIMITER 

You MUST utilize an aftermarket rev limiter (such as the Micro-Touch) installed prior to running the "Signature Series" GSX/GTX 951 Limited exhaust system. (AGAIN...the 1998 and 1999 rev limiters are DIFFERENT!)

1. If utilizing the Micro-Touch Rev Limiter, set it at 7750 and the timing retard at 1/2 degree. (1998 model). When the 1999 models become available, we will be able to give further specifications for that application. 

JETTING INSTRUCTIONS 

Jetting reccommendations with a completely stock boat run at sea level should remain at stock settings. It is highly suggested to make sure that your boat is running rich enough, and perform a plug test prior to running at full throttle extensively. THIS IS YOUR RESPONSIBILITY!!

If you are running other aftermarket performance items such as flame arrestors, head, etc., it will be up to YOU to make sure that your boat is jetted properly as jetting WILL be required!!

If running aftermarket flame arrestors(ONLY),the jetting we have utilized (at sea level) are: (To be used as a GUIDE LINE ONLY!!! Even a modified head or modified prop used in conjunction will alter these) Also remember that if running aftermarket carbs, that even though these may be "preset" by the manufacturer, they may need to be altered when run with this exhaust.

2.3 needle & seat

95 gram spring

95 pilot

160 main

1 1/2 turn Low speed (turn all the way in and back out)

1/2 turn high speed (turn all the way in and back out) 

Tuning Tips 

For the knowedgeable personal watercraft enthusiasts, we encourage you to experiment with water flow and jet sizes with this system to give you the maximum performance benefit with YOUR PARTICULAR SET UP. (This is to be done at your discretion). We have run the waterlines and jet sizes to perform to maximum OVERALL benefit on a stock boat, however, depending upon your application, you may want more bottom end torque or top end speed gain.

Also keep in mind that running a different prop or repitching your stock one will effect how much water pressure will be delivered to the pipe for tuning. You may need to adjust your water directly to the pipe to accommodate for this. 

Reccommendation: On the stock and limited GSX/GTX model boats, you may want to take 1/2 to 1 degree off of the trailing edge of the stock impellor to reach maximum rpm. 

Reccommendation: This system is water controlled via water injection and fixed jets within the system. It is suggested to run a sea strainer in conjunction to aid in preventing sand/debris sucked up from the pump from clogging these jets, etc. 

THANK YOU FROM THE MANUFACTURER 

Thank you for purchasing the Coffman "Signature Series" Seadoo âGSX/GTX 951 Limited Exhaust System! Should you have any questions regarding your new exhaust, please do not hesitate to contact us at the below phone, fax, or e-mail. 

COFFMAN'S EXHAUST SYSTEMS

181 Wabash Ave. Ukiah, CA 95482 (707)462-7881 or (707)462-9366(fax) or coffmans@pacific.net (e-mail)