Having built 30 Yams and an assortment of Hondas, Montesas and Ossas over the last
3-4 years it was time to do a Monty Python, “and now for something completely different”,
but what?

About June 2006 there was an ad for a Villiers DMW frame in the UK E-bay trials section,
so enquires were made and yes, the guy would ship it if I won. About mid August the black
painted frame arrived. The top tube is the fuel tank, single box section down tube to the
under rails with a mesh bash plate like the early Bultacos. At the back end some Hagon
shocks mounted well forward on a box section swinging arm. First obvious thing is the fuel
tap is mounted half way along the tube so the fuel in the back can never get out! Oh well,
let’s see if a Yam engine will fit in here. If I cut out the down tube, weld in some Yam tubes
.. cut out that footrest bit etc, etc, and eventually a plan of action comes together. An Ossa
front end, forks, wheel and yokes, (have to make a new stem to go through the Brit
bearings) shift the fuel cock to the back, must have a runner for the throttle cable to go
through, need a bracket for the top coil, rewire the motor for the ignition wire to come up
the front of the frame instead of the back widen the rear shock mountings for the Yam chain
run and we might be close.

Suitable bits are hacked of an old Yam frame, the old cases from the engine that was used
as the 320 Majesty donor engine are screwed together and the alloy bash plate to act as
a template for the layout of the other engine hanger mounts. Welding has not been a skill
of mine so professional help was brought in and phase 1 started.

So it comes back and the initial build begins. The pre-prepared engine is offered and after
minor adjustments (as Father said “Don’t force it, get a BIGGER Hammer!”) it fits. The fuel
cock is well out the way of the new (BJ) Mikuni and the much modified Yam exhaust slips
through the frame and because it’s a foot shorter and inside the frame rails doesn’t
require a heat shield.

The front end looks about right and because there isn’t a fuel tank the lock is virtually
limitless. Sounds like everything is going very well at this stage? NOT SO FAST newbie!

The swinging arm pivot point is too high and needs to come down ¾ of an inch, the arm
itself needs to be shorter by about 2 inches. Take it all to pieces again and go and get the
garden hose. Try and fill the tank but it leaks like a vegetable colander and we have water

Back to the welder for some easy repairs we hope. 2 weeks later the frame comes back
and still leaks like sieve but I’m reliably assured “Kreem” will fix it. Back to second assembly,
or in this case not as I can’t get the engine in or the bash plate to line up, and after a lot
of measuring it seems the frame has contracted about half an inch under all the heat
treatment. Moral of the story leave the bash plate on! Once more into the heat and some
serious heat bending of those down tubes to get the motor back in. For those not in the
know it looks like it was designed that way. (Reader say nothing, or I will be forced to eat

Well it now looks good but the fork angle is a bit steep, and will the fender hit the exhaust
under hard braking or a downhill drop off? The new pegs are welded on along with the
Yam rear brake mounting and it’s ready to send off for plating.

While it is away the graphics are made, YAMOSSA or OSSAMAHA? I’m counseled that
OSSAMAHA might be construed as something that should have bin ladin after it but I reply
that BIN might have been appropriate as it crossed my mind when all the water was
pouring out of it and could easily have ended up there!

The plating shop tells me they are having problems with all the original nickel that was on
the frame and that it will need to go through again, but eventually it emerges in all its
gleaming beauty.

Now a weekend of cake making as the tank is prepped and readied for the Kreem. It’s
one thing to follow the manufacturer’s instructions of “roll the liquid around until it sets”
and that may be OK if you are just dealing with a 2 gallon tank but twirling an entire
motorcycle frame around like a cheerleader becomes a bit tiring after the first hour ..and
still the Kreem refuses to set. 3 hours later some of this stuff is beginning to stick but my
arms are sore and I keep smacking myself about with the down tubes as the Superbowl
cheerleading continues. Time for a beer!

Sunday and the liquid is getting stiffer, and so are my arms. Eventually call it quits and tip
out the last bit of the goop. Building begins, engine fits without Daddy’s hammer, and
super shiny exhaust bolts into place. Fit the new BJ bash plate and then the Ossa front
end, some Miller stays and an alloy front mudguard. The seat has been recovered to go
with the purple/gold color scheme and the Hagon shocks finish off the rear end of the
frame. Fit the rear alloy guard and now time for a little improvisation to stop muck coming
forward from the back wheel. Rubbermaid dish drainer cut to size to go around that top
tube and then sprayed purple. A new universal chain tensioner is on and a retaining
bracket for the spring is fitted on the back on the motor. 3 days of bending a purple truck
mudflap have given the right shape to slip over the swinging arm and now acts as a
protector where the chain will run. Up front with all the purple cased electrics the kill
switch wire runs straight up the inside of the new steering stem and is very neat.

Engine wise the motor was rebored, new points, the BJ carb, reeds and spacer fitted.
Some clown had fitted the clutch incorrectly so the inner basket was locked up solid so
on with a spare and while we are in here some new plates and springs. Dump the pump
and makes a flat cover for a change.

Now for the Will it? Won’t it? It takes on fuel and believe it or not it DOESN”T LEAK!!!
3 prods and the 32 year old motor bursts into life. Now can I ride it? With all this lock
what will happen? Will it go straight on with the wheel at 90 degrees? If it is leaned into
the turn will the wheel go forwards or backwards? Well none of the above it just does
what you ask! Want some more turn? Turn DEM BARS! If you slip the clutch you can do
a full 180 degrees and the rear wheel just casters on the spot like an ice skater doing a
sit spin. None of this bunny hopping for me! The new BJ reed spacer makes the crocodile
TY250A motor a lot less snappy and it’s a joy to ride. A bit of fiddling with the Ossa front
springs, old ones were grannyish and a bit saggy so some multirates were tried but
finally I settled on the replacement ones from Keith Lynas and these keep the front up
and so far haven’t caused any problems with the fender clouting the exhaust and all the
memories of the 1975 Scottish when I shortened the frame by 2 inches on Rannoch
Moor trying too hard to get into the British team for the 75 ISDT.

It has its first outing this weekend at the Arizona Trials season opener… more news as
it breaks.

Tony Down

P.S. Another one of these DMW frames (Dawson Motor Works) came up on e-bay just recently.

Here are the Ref Nos for those that are interested.

Item 8077368568


P.P.S The next project is a 1960 Don Morley Royal Enfield 350 Bullet Trials. 5″ ground clearance,
55 inch wheelbase!

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  • 9/7/2009 12:52 PM Dan wrote:
    Gorgeous bike. Very well done. If you ever get bored with her and want to ship it to Colorado I would love to take it off your hands.
    Reply to this
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