1977 Yamaha XS1000 Four - 2-Page Vintage Motorcycle Article

Description

1977 Yamaha XS1000 Four - 2-Page Vintage Motorcycle Article
Original, vintage motorcycle article
Page Size: Approx. 8" x 11" (21 cm x 28 cm) each page
Condition: Good
YAMAHA
XSIOOO FOUR
Yamaha joins the one-liter club.
Yamaha's lOOOcc four-cylinder four-
stroke was the best-kept secret among all
the new 1977 models. We knew the com-
pany was developing a one-liter machine,
but we didn’t expect to see it so soon after
the introduction of the firm's 750 triple.
The XSIOOO may turn out to be the
fastest motorcycle you can buy. In some
respects the bike is an XS75O with an
additional cylinder, since both machines
are transverse four-strokes incorporating
double overhead camshafts and shaft
final-drive systems. The two engines share
the same 68mm bore and 68.6mm stroke
dimensions (which give the bigger bike a
total displacement of 996.4cc). Both bikes
have similar 34mm Mikuni constant-ve-
locity carburetors (making the XS 1000 the
first vertical four with CV carbs), and use
Hy-vo chain primary drive systems. The
XSIOOO has an inverted clutch basket like
the 750's, and spiral-bevel gears similar to
the 750's are used to “make the left turn”
out of the transmission to the driveshaft.
There are some special pieces in the
1000. however. It is the first of the big
roadburners to come equipped with ca-
pacitive discharge ignition and vacuum
advance. The big machine uses nitrogen-
charged rear shocks, and a 17-inch diame-
ter cast alloy rear wheel is mounted on a
4.50 cross-section Bridgestone intended to
provide optimum tire life.
The bike shown here was the first pro-
totype in the U.S., and the production
machine may vary in any number of ways.
Upon receiving the 1000. Yamaha's testers
immediately compared it to the Kawasaki
KZ1000—and the Yamaha was unques-
tionably faster. However, the four-into-
two exhaust system sounded—to us at
least—as though it will have to be hushed
up a tad before the government will find it
acceptable. Even still, the XSIOOO may
turn into the new performance king.
Now that all the big street bike man-
ufacturers (except Suzuki, who is working
on one) have 1000s, where do they go from
here? Can bigger engines, perhaps more
cylinders, be shoe-horned into conven-
tional motorcycles? Apparently, because
some of the Japanese companies are ex-
perimenting with 1200cc and 1500cc six-
cylinder models (although we know of no
plans to produce any of them yet). The
question is: When does Bigger become
Too Big?
From here it looks as though Yamaha has
redefined the limitsofsports-touring motor-
cycles with the XS 1000. The bike is a unique
blend of narrowness (compared to the flat-
four design of the Honda GL1000). reliabil-
ity. low maintenance (because of its CDI.
shaft drive and 17-inch rear tire), styling,
and—hopefully—power and handling. We
can hardly wait to ride it.
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