Find
a racer…
I'm
sick of travelling the length and breath of this
country! In a van, rain or shine, servicing dosing equipment in dreadful,
mostly old and run down paper mills, your feet submerged in various chemicals,
what they call "polymers", substances that get slimmer the wetter
they are… This is a gloomy Friday in March 96 and the boss tells me there's a
problem in one of them down in Oxford and I'll have to go tomorrow, like it or
not. I remember there is a Club Committee Meeting on the Sunday at Paul's in
London and decide to make it as well: a quick phone call to my friend Neil in
Reading confirms I can go to his place and he'll be happy to give me a bed for
Saturday night. That's very kind of him for he has just become a father and the
new family is probably very busy, especially at night time…
With
the travelling and the work at the mill, it's no surprise I arrive in
Half
way through them, I fall upon this ad: “”For sale, 1966 XLR hill climber””…
There's a small photo of what looks like a Sportster
with an elongated KR rigid end, my suddenly keen eyes scan like mad. I can see
it's got the racing frame and there's a magneto where the dynamo normally lies
in front of the engine. I look at the cover to see the date: October last
year…Well, 6 months, it must be gone by now, never mind, I still tear the page
away and I will give the guy a phone call next week.
So,
Monday, I phone this Mike in the States and get his wife, he's at work…Phone
him at work, he's an engineer in a bicycle factory. He tells me the bike is
sort of still there, another chap phoned when the ad appeared but wanted to see
it…alas, the XLR is stored away, top of a hill, 4 feet of snow around its shed
so nothing will happen till Spring. I tell him I'm
interested and I don't need to see the bike as it's obvious to me it's genuine.
I still ask for some photos so I can judge the amount of mods
it has suffered on the rear end. Mike also says he's got all the bits to put
the suspension back on, including some early 60's racing rear shocks.
After
receiving the photos, my mind's made up, I have to
have it! But I only have about half of the monies needed…A despairing Susan let
me raid her saving account for the rest… The deal is done: I will send half,
Mike will send the cycle parts, I send the rest and he'll send the engine.
Still, I have to wait impatiently as he attempts a few "dummy" runs
up this hill covered in snow with a friend's 4x4 truck. Success at last, the XLR is now in his garage
in Sun Prairie,
The 1st
crate arrived a few days later and I hurry up one late afternoon to
Same
trip’s on again to
Believe
it or not, this is on Friday and the
Well,
Gordon and Stuart are at Houghton so we do manage to push start it but sadly,
it refuses point blank to rev over 2000rpm, the plugs go dead past that… More
investigating required. Back at base, next weekend, I lift the top end, mainly
to see why the heads are not aligned and it's a whole new can of worms… Not the
heads actually, it's the cylinders that have had their threads machined
"out" for some unexplained reason. But the pistons are the
surprise…the domes, sort of flattened on top on std Sportys,
are going all the way up and nearly as sharp as a knife. The pistons look big
as well, time for some measuring. The vernier tells
me they're 3"3/16 and fitted in cylinders that are about 1/2" thicker
than std, still with the right part number cast in
them!!! Might as well check the
stroke…4"9/16… So the beast is 1240cc, with what appears to be a std combustion chamber with the rare 57' small valves… A
quick computation gives me a compression of about 14 to 1 with the higher
domes… No wonder 4 star won't fire it. I'll have to go
for methanol but I haven't got a carburettor set up for it. To see if I'm
right, I borrow one of Stuart’s methanol carbs, a
36mm Spanish square Amal, from one of his ESO grass
trackers. Oh yes, it starts easier and go through the
rpm range… Time to try it on a 1/4 mile sprint, 1st hundred yards no
problem, after that, no methanol left in the float chamber and the engine's
starving like mad… Back to the drawing board. A later
visit to Peter Collins of speedway fame unearths a German twin float assembly
grafted to a Spanish Amal that should solve the
problem. The bike is not starving anymore but I can't seem to find the right
jetting, the engine seems to overheat a lot and 1200deg paint only last a
minute on the pipes when running. As well, it's quite a modern carb and somewhat kills the good looks. I have in my boxes
of long time ago acquired bits a mean looking S&S 48mm early 70's MGAL,
with side float and big fuel inlet but it's a petrol one. Never mind, it must
be possible to modify it to accept methanol. A quick phone call to S&S
brings no help, they think I cannot do it, but, hey, I'm the "mad
owl" by now so anything's worth a try…
Only
took about 4 years to get it right, that involved having the iddle/intermediate circuit re routed on the outside, the iddle jet being no more than a 3mm bit of brass rod drilled
to suit and stuck between 2 lengths of plastic pipe and an adjustable air screw
further up. A 3mm main jet (!!!) still wasn't big enough so I installed as well
another 3mm main jet with an adjustable Mikuni high speed needle in it. In the
meantime, I discovered both why it overheated and the origin of the crank… I
told myself the spark timing might be a bit out so I eventually put a degree
wheel on the crank and discovered the timing mark was at 38 degrees before TDC
which is the racing side valve timing, so this is a KHRTT crank. When timed
between 48 to 50 degrees, the performance just went through the roof… My last
big outing was a French hill climb, proper hairpins an’ all, 5 climbs and I was
absolutely dead from the efforts of trying to wrestle with that animal… The
slightest opening of the throttle makes it want to rise vertical and the
slightest closing of it makes you go over the handlebars such is the amount of engine
breaking…
Patrick