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BBG-ST4s Maintenance Issue Log



Maintenance Log


Information on setup and use of JP Diag ECU diagnostic Software

ECU Installed in 2002 ST4s: 59M  The TPS is PF09

IAWDIAG ECU Diagnostics Software and ECU Reader and Writer.

Info and How to for Superseal 1.5mm AMP connector pin removal and assembly

Fork Overhaul and Oil Replacement - Ducati ST4s Showa Forks ('02-'03 Ducati ST4s)


2002 Ducati ST4s Manuals:

Work Shop Manual (large file +35Mb but text searchable) 

Parts Manual

Owners Manual (IT, EN, FR, DE)



Torque Values

Handy Capacity Values for ST4s:

Oil Quantity 3.7L ~ 3.9qts
Coolant Quantity 3.5L ~ 3.7qts
Fuel Quantity 21L ~ 5.5gal

Front and Rear Wheel Torque Values

  Ft-Lbs N-ms
Front Axel nut -- 28mm socket for nut 46 62
Front Axel Pinch bolts -- 12 mm head 14 19
Front Brake Caliper retaining screw 30 43
Rear Axel nut -- 30mm head 61 83
Rear Chain Adjust bolts -- 12mm head 5.9 8
Front Sprocket Plate bolts -- 8mm head 4.4 6

Oil Change Related Torque Values:

  Ft-Lbs N-ms
Oil Filter Cartridge 8 11
Oil Drain Plug 30 42
Oil Mesh Screen 30 42
Oil Mesh Screen outer Cap 30 42

Engine Mount Bolts Torque Values

  Ft-Lbs N-ms
Rear engine mount bolt -- 12mm bolt thread (14mm bolt head, 15mm nut) 45 60


Link to Other Torque Values

Following a complete tear down, overhaul and cleaning, I reassembled the BBG ST4s and gave her a couple of test rides.  Initially start required a good bit of key cycle to prime the fuel system and start button engagement to spin the engine, eventually firing.

1. Hard Start:  When engine is cold, it requires lots of cranking until it finally fires and will hold an idle.  Like 10 or 12 iterations of Key "ON" and Starter button press and hold for a few seconds turning the engine over, until its clear it is not going to fire or it fires and dies.

-- Replaced the Fuel Pump relay (under the seat) and it improved a little, but sometimes she gets a bit finicky, definitely doesn't like being cold. 

-- Going to conduct a TPS baseline adjustment.

2. Right fork seeping:  Both forks were flushed and refilled with Spectro 5w spec fork oil at bike overhaul but were not disassembled.  The right fork is leaking at its seal.

-- Overhauled both forks, replaced inner and outer bushings and installed fresh seals and dust wipers -- new Spectro 5w fork oil.



Events and Receipts

1.  Purchase and Records:



ST4s Non Linear TPS - Set Baseline Adjustment

Brad The Bike Boy has a comprehensive page dedicated to this with the CAUTION: Do NOT connect Diagnostic SW and press "TPS RESET" - NO!  Do NOT do it if you have Non Linear TPS (like my 2002 ST4s does)


Vinnie's info on TPS Reset

Follow Brad the Bike Boy's instructions.

I back probe the TPS at the connector, red lead (+) from my multi-meter to the #2 wire (orange) in the middle of the connector, and my black lead (-) to the #3 wire (black & violet).














Install and Set Timing Belt Tension Values using acoustic vibration:

Measure and set Tension on timing belts:  110Hz on new Ducati OEM belts and approx 90-100Hz on existing belts. Set tension at 100Hz for New Exact Fit belts (CA Cycleworks).

To set the belt tension, the cylinder you are checking MUST be at TDC so that there is no tension applied to the belts by the closing springs pushing on the rockers.

1.  For the horizontal cylinder it is the forward run between the tensioner pulley and the exhaust camwheel (posn 21).

2.  For the vertical cylinder it is the rearmost run between the idler pulley and the exhaust camwheel (posn 25).


Suspension Info

Preload (24 Dec 20)

F1   R1  
F2   R2  
F3   R3  
    Front Rear
1-2 Static Sag    
1-3 Rider Sag    

Ohlins recommendations:

    Front Rear
1-2 Static Sag 15-30 10-20
1-3 With Rider 35-50 25-40

*measurements in mm.

25 December 2020

Front Rear
Compression Damping 11  
Rebound Damping 13  
Preload 2d line from top  

Tire Pressures: Front- 33PSI; Rear- 35PSI



BBG-ST4s Issues


1st Issue...



2nd Issue... 







ST4s 2002 USA Parts Diagram: click link for pdf