Andrew Chapman wrote:
> Salad Dodger wrote:
>> On Sat, 24 Jul 2010 09:32:08 +0100, Pip Luscher
>> <(E-Mail Removed)> wrote:
>>
>>> Hmm. I have ridden an XS750 frm London to Cambridge on two pots and
>>> a Guzzi one mile on one pot to get home, but neither was a) spewing
>>> oil out of the exhaust or b) churning bits of piston around the
>>> cases.
>> <HEROIC FAILURE MODE>
>>
>> I rode my KH250 from Falconwood station back to Gillingham
>> (A2/M2/A278 - including the long drag up from the Medway bridge)
>> after it had lunched its near-side piston rings.
>>
>> It was everso untidy in there after I'd whipped the head off when I
>> got home.
>>
>> In my defence, I was only 19, and it was only 29 miles.
>
> If we are on tales of this kind I once rode an MZ250 from Birmingham to
> Leeds with a holed piston. Somewhere around Coventry it started
> misbehaving and would only run with the throttle wide open - so I just
> held it against the stop all the way. My mate (who owned the bike came
> up the next weekend and we stripped it down to find a hole in the
> piston. He just replaced it and it was fine. The MZ250 might have
> been a bit agricultural, but it was a solidly built thing (with totally
> c__p brakes!)

Can I join in?

I set off from Hornchurch in 1967 to go to the IOM TT. I'd borked my
femur the previous year, and kneebend was in short supply, so I fitted a
Watsonian scooter box sidecar to my T35 Douggie.

To keep the thing down on left-handers I filled the box with tools and
camping gear. Still a bit on the light side, I heaved in some spares as
well.

Halfway up Hertfordshire there was a loss of power and misfiring on the
nearside pot. I couldn't see anything wrong, so I cleaned the plug. It
ticked-over fine, but a bit of throttle, and half of it died. In the end
, thinking to clean the carb I found that the needle in the main jet had
come adrift, so the slide went up and down, but the needle noddle noo.

Approaching Norman Cross on the A1, I gave it a bit of wellie and the
crankshaft twisted on the journals.

RAC towed me into a fine motorcycle shop and scrapyard in Stamford,
where I pulled the engine apart. The owner of the place gave me the use
of his Alpha True, and I tapped the crank back into line, and arranged
for the journals on the spare to be spot-welded while I rebuilt the
engine with the straightened crank.

Tempus was fuging.

All went well until Grantham when there was this shaking. Douglases
don't shake. Then the nearside exhaust pipe flew out of the pot and
waffle-box. I tapped it back in and set off again.

Still shook, and this time I ran over the pipe and adjusted the
circularity of the waffle-box end. Using one of those deathtrap concrete
pillars which signs used to be hung on as an anvil, I corrected the
flatness enough for the pipe to be replaced. Then I started the engine
and watched.

The nearside pot was pretending to be a piston. "Bah!" I thought (or
something like that), expecting to have to look for 6 x 5/56th" BSF nuts
to resecure the cylinder to the studs. Not a bit of it - the pot had
sheared right round its circumference just above the crankcase.

A Spanish windlass round the pots and engine got me to a safe parking
place, and I hitched back to Hornchurch to pick-up a pair of pots and
pistons.

However...

They turned out to be early Plus series, which had 3/8" stud holes and
which bumped-up the c.r. by one.

Unfortunately...

Th pistons were also Plus 90 ones, and they bumped-up the c.r. still
further. We went from 7.25:1 to nearly 10:1.

I was running out of money and the TT was about finished, so I set off
back home. In Stamford again, I bought a short piece of brassed curtain
rod, which cut up nicely for spacers round the studs. Then I carried on.

Eeee, but she flew!

CLUNK!

Sodding crankshaft again! I pushed the lot the half mile to Norman
Cross, where there was an offroady bit behind an RAC box. I drained the
oil, had the engine out, and split the crankcase, I used the blowlamp to
heat the front half and change the mainshaft bush.

In a remarkably short time I was ready to put the lump back. The RAC man
remarked that he'd seen some roadside repairs, but this took the
biscuit. Then I heard another Douggie pull up in the layby. "Here's help
to get the engine back in!" I thought.

It was me mate Ralph Killips on his way home from visiting his folks, an
we rode in convoy, I to Hornchurch, then he went on^h^h^back to Romford.

I have left out a few fiddly bits, but I don't want to clog-up the server.

--
Rusty

/Oily wrote:

Tristicated wankshafts/

> I think I've mentioned this before, the exact reason I outed seven of the
> heaps of shite for £7.00

A spot of weld either side of each end of both crankpins solves the
problem, and as long as you aren't too enthusiastic (No 10 jet on oxy,
or 140 amps for a measurable time...) the blob can be cold chiselled-off
without too much trouble innit.

Another mod is to molish an increased volume/pressure oil pump and an
oilfeed into the back of the crankshaft.

--
Rusty

Oily wrote:
> "Rusty Hinge" wrote:
>
>> /Oily wrote:
>>
>> Tristicated wankshafts/
>>
>>> I think I've mentioned this before, the exact reason I outed seven of
> the
>>> heaps of shite for £7.00
>> A spot of weld either side of each end of both crankpins solves the
>> problem, and as long as you aren't too enthusiastic (No 10 jet on oxy,
>> or 140 amps for a measurable time...) the blob can be cold chiselled-off
>> without too much trouble innit.
>>
>> Another mod is to molish an increased volume/pressure oil pump and an
>> oilfeed into the back of the crankshaft.
>>
>
> You run 'em too easy. Stripped one crank completely, ground a bevel on the
> ends of the pins and filled them completely with stick welder and they still
> broke. They might have been ok with a centre bearing as well. Trouble was
> with the gearchange when thrashing them proper it was a not-so-positive
> action and occasionally missed a gear and over-revved the engine. Then I
> grew up and decided something with a bigger engine was a better bet and
> still is.

Next cheap Douggie you find you can hurl my way.

Mined ewe, that goes for a lot of other SOBs

Oe of my mates lightened a Mk# frame and ditto for engine. He fitted a
home-made triple capacity oil pump, a bush instead of the self-centering
ball-raace at the gearbox end, and an oil feed through the back main to
the rear big-end.

He shortened the pots a bit, fitted +90 pistons, opened-up the inlet and
exhaust tracts, polished them like unto mirrors, replaced the valves and
springs with Triumph ones, stirred in 1" Monoblocs, replaced the cams
with Stellite-coated high-lift ones of his own manufacture (yes, he was
an engineer by trade) and improved the gearbox.

This was based on a + series one, and the main mod was to turn down the
selector pegs and clothe them with (IIRC) 5/16" rollers from a Reynolds
chain, and secure them against falling off...

This made for a highly slick gearchange, which I can vouch for, as I
restored a worn gearbox myself that way.

One (500) Goldie owner was disparaging Douglas chamines, and Pat
accepted a contest. Goldie got off first, but shortly after that Pat
screame past him.

Back at he Lay-By, the Goldie rider asked: "How fast does that effin'
thing go? I was doing 105 when you went past me!"

"You must have a tuned speedo, mate:" Pat replied "this only does 90."

--
Rusty

In message <i74nd0$a5d$(E-Mail Removed)>, Rusty Hinge
<(E-Mail Removed)> writes
>
>"You must have a tuned speedo, mate:" Pat replied "this only does 90."
>


--
Mark Roberts

Oily wrote:
> "Rusty Hinge" wrote:

>> Next cheap Douggie you find you can hurl my way.
>
> I'm not likely to come across anything cheap these days unless it's a basket
> case which will probably cost a fortune to complete anyway, but yes, if I
> come across one now I will pass on the details.

TA

>> Mined ewe, that goes for a lot of other SOBs
>>
>> One of my mates lightened a Mk# frame and ditto for engine. He fitted a
>> home-made triple capacity oil pump, a bush instead of the self-centering
>> ball-raace at the gearbox end, and an oil feed through the back main to
>> the rear big-end.
>
> Can't see the point of that really, the oil delivery was never a problem,

The volume and pressure wasn't, but for some reason the oil tended to
sidle by the front big-end without visiting.

> and
> you could still get home with an out-of-line crank with only a damaged front
> bush to show for it. It would probably not run at all with a bush either end
> in that case.

Nah - seizes up: crank hits crankcase.

> Having said that, it is about 50 years since I saw the inside of one of
> those and to be honest, I can't remember how the oil pump is set up now.

Getting on for that here TAAAW. There's a triangular-ish hole in the
bottom of the sump, and the (eccentric bore with vanes on the rotatybit)
pump is stuffed (and screwed) in it. IIRC it runs off one of the camshafts.

--
Rusty

Rusty Hinge wrote:
>
> platypus wrote:
> > On 23 July, 22:29, stephen.pac...@gonemail.com wrote:
> >> Pip Luscher <plusc...@live.invalid.co.uk> wrote:
> >>> I overtook one on the Aprilia a few days ago on the A14, and saw one
> >>> this morning in Black Bear HD's car park as I was taking T to nursery.
> >>> They may be shite old Brit iron but I do like seeing them.
> >>> Given their rarity, I imagine it was the same one.
> >> I saw one on the way to Chimay. It was just in front of an old boxer...
> >> by the side of the motorway.
> >>
> >> I stopped and they thought it had holed a piston. They were proposing
> >> to ride it the two miles to the next junction. Madness.
> >
> > It's for situations like that, that I usually carry a tow-rope of some
> > sort.
>
> My mate used to carry a pot-mender and a tube of Green Hermatite.
>
> Got him home once - Ariel VB and double adult chair.
>
> --
> Rusty


My old Ariel 500 twin put a conrod through the front of ther crank-case
(in 1969) about 100 miles from home. (New Zealand countryside - no bike
shops for 100 miles) Tied the flappy end of the conrod to the frame,
cut a tin can to fit over the hole, wedged it in with a chunk of
firewood
from a nearby house, pulled the sparkplug, and rode it home, topping up
the oil every 5-10 miles. I got most of the leaking oil back, soaked
into
my left trouser leg and boot. (and foot) It went quite well as a 250cc!
Was a bit worried when I hit the city, what with roundabouts and a very
well oiled back tyre.

Greg.P.
NZ