conversion to unleaded

since im a tight a**.....im thinking of buying a nice cheap 1980 model
1200cc sports bike...but i hate the thought of using leaded fuel. is it easy
to convert them to unleaded? is it wise?

 

Most japanese bikes have been able to run on unleaded from the 1970's.

You just have to use 95 octane or above.


G-S

 

Anything Japanese should be fine already. If it pings, you might need
to go a higher octane rating is all. Japan went all unleaded in 1978 or
1976 or something.

1980 model 1200cc sports bike? Doesn't ring a bell.

-----sharks

 

since im a tight a**.....im thinking of buying a nice cheap 1980 model

95 PULP works well. If you're really anal about it add 1 mil of
flashlube per litre. If you buy it in 1 ltre or larger bottles it works
out to about 1c a litre extra.

 

cool. i meant just any big bike from the 80's

 

I can't think of a single 1200cc sportsbike throughout the whole 80s
(except a Harley Sportster)
Clem

 

You wouldn't be yet another kid flouting the 250 restrictions would you?

 

haha.....nope im a good boy, had my 250cc lic for 8 years...am baout to
upgrade

 

FJ1200? Although that might be pushing the definition of "sportsbike" a
little too far ...

.... or maybe not.

-----sharks

 

Ahh; well done!
The FJ1100 was definitely pitched as a super-sport and while the 1200 was a
bit more touring-orientated (and the cutting-edge had moved on a bit) I'd
still happily class it as a sportsbike.
Sharkopedia!

 

I thought maybe a Jota... but I'm not sure they were made in the 80s
or not.... Crap Old Italian Bike Experts to the fore, please..



paulh

 

You can't buy leaded fuel in Australia anymore.

If it's Japanese then it'll run on unleaded fine, you might need to use
premium to get the right octane though. If it's a 1200 skirtster then
fucknose. Euro bikes of that era - probably fine, can't recall when they
cut over.

JL

 

Harley Skirtster of course.

Boxer

 

Was there ever a 1200 Jota?
There certainly was a 1200RGS which would've been sporty enough (at the
time) to be included though.
Well done!

 

1200 Mirage. Vibrated worse than the Jota and drank more fuel - 30 mpg
wasn't uncommon. Nearly bought an Jota, but it was a top heavy beast, so I
decided on a MHR Ducati instead. Sold the Duke after my big accident in 85
(I was on my GT750 at the time, which was written off) to keep the missus
happy. Should have kept the bike and got rid of her.

Andrew

 

Is that the right link?
I couldn't find it.
(And the Laverda 1200 link has a piccy of a 1000 Jota)

 

There's certainly a loy of Google hits for "Laverda 1200 Jota" but they all
seem to be 1200 Mirages, plain 1200s or 1000 Jotas.
I'm not yet convinced.

 

Now I've heard the name 'Mirage' I'm sure thats what I was thinking
of... not a Jota.... its been many a year....its still an 1200cc(ish)
80s 'sport' bike


paulh

 

The Jota was Slater Brothers, UK Laverda importer taking a 1000C
Laverda (later to be known as the Jarama) and slotting in a load of
factory race parts (silly pistons, cams and so on).
It was fast, especially for its day with 140mph from a well sorted
one.
Only thing was the weight which meant it needed bossing round corners,
it also had a tendency to eat tyres, chains, brakes and riders due to
the long wheelbase, high mounted weight (it was a bit like riding a
high-mounted plank) and the wonderful crank offset of 180° - it ran
with two pistons just like an old 360° twin with a spare one grafted
on the end...
Grunty, good torque until the revs reached around 4000 when the cam
timing, accelerator pump Del Ortos and the 3-1-2 pipes all began to
flow properly, the noise changed from a growl to a shriek and off it
went, hopefully in the general direction you wanted.
Laverda SPA liked the idea of Slaters frankenstein and added it to the
range.

Now then... the 1200... that was to later become the Mirage, just a
1000C engine bored a bit and tuned more as a sport-tourer *ahem*.
It went well enough but never quite had the appeal of the big orange
thing.
It handled much the same, drank more deeply and in other respects was
not much of an improvement over the 1000 models.
The last version of the 180° crank models (the 1200TS) got a handelbar
mounted fairing with some plastic 'sports lowers' and used to go into
a weave around 120mph.
Unsettling on something weighing that much.

Later model Jotas got the 120° crankshaft treatment which smoothed out
the vibes a little, although if you ride one back to back you might
prefer the 'lumpy' vibes of the 180 and the added urgency of the
4000rpm thrust, rather than the tingly high frequency vibration of the
120 model. The 120's were no faster, with the exception of the RGS
Corsa and SFC models which were a touch more tweaked, allegedly good
for 150mph.

Having worked on Laverda engines on Jotas and Mirages I have to say
they are very well put to gether for a 1970/80's Italian, proper
bearings, well machined parts - they do speak quality. Easy for
someone with reasonable engineering skills to maintain too, although
the shims-under-buckets design isn't to everyones taste.
One thing about all Lav's is the rediculously heavy clutch, which is
due to too small a leverage on the operating arm at the gearbox end.
There used to be a conversion (me mate did one on his own as a copy
once he'd sussed out how) which cut a slot in the sprocket cover and
used an extended operating lever, but you had to have a cable holder
either TIG welded or bolted to the top crankcase in order to line up
the cable properly. I'd say it was worth it as the clutch then felt no
heavier than a Super Dream.

Anyone tempted to by an old Laverda now should be bloody careful about
what they're buying - there are some nicely looked after examples but
they DO need regular maintenance, so daggy ones are probably going to
cost you heaps to rebuild/repair - and some parts are now manufactured
from unobtainium.
They do, however, last very well provided they're maintained and not
caned remorselessly without an equivalent amount of servicing.

Aye well... there you go.

Back to me book.

Jeffles

 

JM wrote:

Wot Jeffles said... I,too, liked the idea of it.

The noise, once it started percolating, was truely awesome.

The height and weight of it, too, was awesome. :-(

The one I rode, with a view to purchase, had only a centre stand, I
think they were standard like that.

At the time, I could have bought the bike, but hiring the seven foot
tall, trained gorrila to follow me about and hold the bike when I
stopped, and put it on its centre stand for me, was going to be too
expensive.

regards,
CrazyCam