Suzuki 1972 GT750J Two-Stroke Question

The Suzuki 1972 GT750J Two-Stroke was the first Japanese water cooled
motorcycle, two stroke or four stroke (Scott made a water cooled
two stroke in the 1930's).

Is the Suzuki 1972 GT750J Two-Stroke the largest production
two stroke motorcycle made at being 750cc? Did anyone make a bike
larger than 750cc except race bikes. (I've heard someone made a
1000cc race bike but never made it into production for the public).

My last question is why is it that most two strokes even models
from the 1980's and 90's have a low milage between rebuilds (like
20,000 to 30,000 miles) but the Suzuki GT750's usually get between
90,000 and 100,000 miles before a rebuild. I've never heard of two
strokes getting almost Goldwing like mileage from an engine. Is this
true and how did they do this?

 

Some outboard boat motors were 1000cc 2-strokes.
I saw a v4 barrels once I think it was an evenrude(? don't know how to spell
it).
what RPM's does the 750 do. it might have something to
do with piston speed, RPM and forces placed on the
smaller parts.

 

The scott started in 1910, and included a 1000cc model.

Moike

 

Yep, and it was a triple! Started as a 750cc triple in 34/35. The
1000cc triple came out just before the war, and not many were made.
(Wars being hostile and all)

http://www.realclassic.co.uk/ridesfiles/rides04052800.html

Fourth picture

Moike

 

There's not a lot thats fundamentally new.

Did you notice the V-twin Bantam further down?

;-)

Moike

 

Sorry to tell you this Clem, but BSA made the triple first, and it was
called the Rocket 3. That cheap Triumph copy with the vertical motor was
called a Trident.

Theo

 

This is the pre-war superbike which was the brainchild of Bill Cull. At
986cc the three-cylinder two-stroke produced 40bhp and propelled the monster
to just short of the ton. quite an achievement, but one which sadly never
went into large scale production.



A little know fact when this bike was dropped from production, the designer
Bill Cull was so depressed the term Culled was coined to describe his
condition. The term survives to this day.



Boxer

 

Clem wrong again, now there's a surprise

Boxer

 

Not with four l's anyway!

Moike

 

Suzuki used, and possibly invented, a lubrication system for two strokes
which was part of the reason for the long engine life of its two-stroke
bikes. The GT750 ran an automatic fuel oil mixing system but with one
important difference from the Yamahas and Kawasakis of the time.
The GT750 triple had 4 main bearings. All ball race.
The one at the end which delivered the primary drive to the clutch ran in
the gearbox oil so that one had excellent lubrication. This was pretty
standard for Japanese two-strokes.
But ... The autolube system delivered pure oil directly into the other
three main bearings.
As the oil ran out of the main bearings it was picked up by the fuel air mix
and swept up to lube the big ends, small ends, pistons and cylinder walls.
There was also a second injector which injected oil into the crankcase inlet
tract which also lubed the pistons and cylinders.
As with all auto-lube sustems the oil pump was linked to the throttle. The
more gas you gave it, the more oil got pumped.

Cheers,
Baz

 

I had hoped someone would believe it.

Boxer

 

Well, you know, you you, as the seamstress said to the
plumber, you you, you don't you worry about that now, OK.

GB

 

Given the recent launch of a film based on a tv series, based on a
record, based on a book, based on a radio play by a certain dead author,
it's probably appropriate to mention the "Award for the most gratuitous
use of the word '****'" in this context ...

Cheers
Goaty

 

1969 to 1972.

Theo

 

Not with three Ls, no.

Theo

 

Yep, he knows all about them. The Clemopedia is proven worng again.

Al

 

wow, a clemspat

 

ta

beer mate?

 

No, he's a rap singer

 

Never said you were "wrong" Clem.

Never seen one of those Rocket 3s in the flesh till Sunday, and seen two of
em on Sunday!

Al