Bill's SOS Page












I am a dealer for: 





 Together with well-known specialists, in particular Tim Barker of B&M Industries, Uli Egetemeir, Heinz Weber, and Theo Appel, we offer one-off parts, engine rebuilds, and advice on tuning and racing with the MuZ Skorpion and Yamaha SZR as well as for the SRX.

William Jurgenson
D-74348 Lauffen am Neckar,
Telephone: 49 7133 16938
Mobile: 49 1747101774
EG VAT Nº.DE145693608

Rearsets by Gilles Tooling. 

The pictures show the prototype set I put together with the help of Michael and Manfred at Gilles. As a result of my prodding and efforts, this setup is now(07/09) officially available for the Skorpion as GT31MZ01R.  I can supply the set and of course it can be directly ordered from Gilles. It is available in gold, titanium and black.

here feedback from a customer:
"Habs nicht mehr ausgehalten und die Rastenanlage doch noch heute Abend montiert. Bin eben fertig geworden, hat super gepasst, hatte ueberhaupt keine Schwierigkeiten und war nach einer halben Stunde schon fertig."
"couldn't wait and fitted the set immediately this evening. Just finished, fit beautifully with no difficulties at all. I was done in  1/2 hour."

Lightened starter freewheel, together with lightened flywheel, this is perhaps the first measure towards quicker response and more performance for the xtz engine. I have this part on stock and it can be easily exchanged in the bike without draining the oil.

Bikeworx manifold kit with Mikuni TM42 flateslide carburator from Topham. Battery box and K&N airfilter are part of the kit.

Mikuni TM34/65 dual flatslides from Topham, modifed to fit stock Skorpion with original airbox; the unit fits so well, that it is unnoticable.

Hollow axle with no protruding head using crosspin and special wrench, can be made of steel or titanium

Dogbones to any desired length of aluminum or stainless steel or titanium

Timing chain coversion to rollerchain from Slipstream Tuning 

We have replaced the crankshaft timing gear with one of our making which is a 1:1 replacement for the OEM timing gear and fits behind the stock starter freewheel.

Skorpion with a new wiring harness using the SilentHektik electronic fusebox

1978 Ducati 900SS with new harness and SilentHektik fusebox and charge controller.

The heads of the Ducati were modified for lead free gasoline with new valve guides and rings.

The owner, Georg Maylaender, pleased with first test ride.

An entirely different project: a 1978 1200cc Laverda Jota (180ºcrank) fitted with Silenthektik Triple-spark ignition, Tarozzi pegs and aluminum wheels. The original magnesium wheels had to go!

The present front wheel is from a Yamaha TDM and fitted with full-floating 280mm rotors from a Yamaha TZ 250RR. This combination fits the original Marzzochi fork and Brembo calipers perfectly without any modifications. Nonetheless, a 3.0/18" PVM wheel matching the rear will be fitted as soon as we have one.

Yet another "project" a Bimota DB1 BOT racer which was successfully used in the BOT series and is now going to be used again for chosen events, No modifications were necessary, only the usual checkup and maintenance. Weight 140kg race-ready!

The 3,75/16" Campagnolo mag wheel was replaced with a 3,5/17" Marvic mag wheel; since no rotor hubs were readily available with the necessary offset, two new hubs were machined  from Al7075 (Ergal)

my "Boley" precision lathe
my "Steinel" milling machine
my small lathe right here in the shop

The 1954 F.B.Mondial is slowly taking shape

Another F.B.Mondial: original 1962 SSV4.

Here with "Klacks" Ernst Leverkus, Paul Simsa, and myself

The "first measure" towards improving the Skorpion, both in handling and performance is fitting decent, relatively light wheels such as those from the SZR which are the same size as those of the Skorpion and are thus legal in Germany. Elsewhere there is no problem.

TZR125 4DL front wheel is exactly the same as the SZR wheel . The 3,4" rearwheel can be made to fit since the the SZR uses the TZR frame and swingarm.  A chainwheel carrier moving the chain out 18mm must be made to correct.

The 4,5" rear wheel of the TZ250R 3MA ist even better because the rim is wide enough for the standard 150/60 tire; the 4" rim is too narrow according to the tire manufacturers. Unforutnately this rim and the later 5" are exceedingly rare.

Personally, I use a 140/70 tire on the 4" wheel or, as shown,  the TZR 4DL 3,5" rear wheel with a 130/70 tire.

For 2007, the racer got a new CNC front brake and radial pump from ABM left
My personal Skorpion using the racing frame is being continually (if gradually) developed. I has a oneoff engine based on a SRX400e with milled out crankcase, 102mm cylinder, full-race billet cam and solid balancer gear. It also has a TZR125 SP fork and a new Wilbers strut made for the present weight and usage. Rear wheel is a Brembo 4.5"/17" from a TZR 3XV, front wheel is a 3/17"Brembo  Bridgestone BT003 Racing are mounted, 110/70 & 150/60. Front brake is a Beringer radial pump, Stahlbus line, the Beringer Aerotec caliper used on the racer with Carbon Lorraine C55 pads, and a 320mm Beringer Aronal cast iron rotor. Rear brake is the wonderful Beringer 12,7mm pump, a Stahlbus line, the Beringer 2d1 caliper and one-off Beringer disc.  Ths reversed shift lever is from Gilles.

The blue Skorpion Tour has been built up as a fun racer with parts from the green bike including, the Barker aluminum subframe, the Marvic mag wheels and ABM brake.  An AIM Mychron 4 instrument was fitted.
The present owner has continued development and has painted it green.

Both he and I have each fitted an IgniTech  Sparker TCDI4 fully programmable ignition box.
MuZ Skorpion Supermono (shown above)
128kg race ready
4 stroke, 5 Valve: 700ccm
weight of race-ready engine with carbs and all fasteners wired:: 40kg
special welded"Porkchop" crank
no counterbalancer
Carillo rod
JE 102mm 12:1 piston
Megacycle Stage 4 cam
Slipstream rollerchain conversion
Kibblewhite springs and titanium retainers with titanium locknuts
ported head
Mikuni TM38/65
Barker 2 in 2 racing exhaust
Barker CNC sideplate
SilentHektik costant loss battery ignition
Yamaha works cluster
This configuration is race-dependable with ±75hp at the rear wheel.
Starting with the stock engine (Baghira, Black Panther, Skorpion, SZR) with 48 SAE hp, a continuous increase up to and including dry slipper clutch is possible. 60hp is possible with every-day dependability. Beyond that, though, every single PS gain costs a lot of money and time -  and nerves.

My personal Skorpion  can be test-ridden at any time.