Suzuki SP 250
Suzuki SP 250
Air cooled, four stroke, single cylinder,
Bore x Stroke
71 x 31.2 mm
Mikuni VM28SS carbs
Transistorized / kick
17 hp @ 7800 rpm
5 Speed / chain
Air/oil telescopic forks, 195mm wheel travel
Full floater, 190mm wheel travel
When Suzuki decided in 1978 to upgrade their entries
in the dual purpose market, they hoped to make one step take the place of two:
the smaller models remained two-strokes, as in the established TS line, but the
new entry, a four-stroke, displaced 370cc. Built as the street legal SP and
playbike DR, the 370 was supposed to offer a bit more than the traditional 250s,
a bit less than the awesome 500s.
The SP and DR370s were good bikes. They did have more punch than the smaller
rivals, less bulk than the larger ones. But they didn't set the sales charts
afire, nor did the later SP and DR400s, again despite their good looks and
performance. Suzuki planners followed their own line of development and came up
with the DR and SP500, meeting the rivals cc to cc, and beating them in many
All of which leads to this year's new idea, the
SP250. As logic dictates, there's also a playbike DR version. As you'd also
guess, Suzuki is tired of trying to make one model do the work of two and
expects to gain 250 sales by making a new and better 250.
The new is beyond doubt. The 250 engine is a smaller version of Suzuki's 500cc
Single, with Twin Swirl four-valve head, a moderately oversquare bore and stroke
of 72 by 61.2 mm. The compression ratio of 8.9:1 and the swirling of the charge
gives good torque and allows no-lead or low lead, in fact Suzuki recommends no
or low with an averaged octane (as shown on the pump) of 85 or better. If the
engine pings, the manual instructs, change brands but don't use leaded fuel.
The 500 and 250 don't share parts but because they're the same thing in two
sizes, the 250 contains a counterbalancer, as seen of course in the class rivals
as well. There are two exhaust pipes for the two exhaust valves, and they tuck
tightly back, join and run into a silencer and then to a secondary muffler,
again like the others except that the Suzuki makes some nice noises. Nothing
rude, but you know it's a healthy little engine down there. Five speeds, oil
carried in the crankcase.
The SP has a Mikuni CV carb. The lack of a
spring-loaded slide and heavy return spring means the SP's throttle is feather
light. Snaps open quickly, almost no resistance and the psychology of that means
the engine feels willing to go.
Along with that, the light pull means the throttle can have lots of leverage, so
it's quick, with maybe a quarter turn from idle to wide open.
Starting is by foot, aided here by a semi-automatic compression limiter. Semi in
that Honda and Yamaha 250s have valve lifters linked to the kick lever. When the
lever is kicked, the exhaust valves are opened. This works but the rider never
knows where the engine is in its sequence of four strokes.
The SP, though, has a hand lever that opens the
exhaust valves until the piston has been eased just past compression. Pull it in
and it stays in until, click, the piston is in the right place.
Again like the others, the SP250 has gained a lot from motocross. Rear
suspension is Full Floater, with one rear shock riding in links between the
frame and the swing arm, said linkage selected to give rising rate suspension,
as done on the RMs and they are known as the best there is. The swing arm is
impressively large, steel welded into a box section and sized for at least as
much stress as they'll ever get/ The rear axle is positively located in sliding
blocks within the arm. The frame is open cradle with the engine a stressed
bridge between the single front downtube and the double tubes at the rear. Drum
brakes, leading axle forks with valves for air, just as you'd expect.
For the past several months these columns have
remarked about how on/off road bikes are using motocross style. The SP250
follows this except that by now the comment isn't accurate. Instead, the short,
high fuel tank with square seat, the short and wide fenders and low handlebars,
came into vogue on motocross models, spread to the enduro lines and now are seen
on the dual purpose bikes, from all the factories at about the same time.
And so goes the SP250. This isn't a complaint. It's a clean design. Excepting
perhaps the rear fender, which is too short to keep water off your back and all
modern motorcycles have that shortcoming except maybe the FLH, none of the forms
of the SP interfere with function. Where the looks are awkWard, for example the
wide front fender, they serve a purpose. Plus the red paint is a warm and bright
red, the contrasting trim stripes don't overwhelm and the finish, on plastic and
metal alike, is top notch. Even the welds on the swing arm are nicely done.
Cost is a consideration in the on/off class, and not much money has been spent
where it needn't have been. The instruments are a speedometer and three warning
lights; neutral, turn signals and high beam. Adequate, but no more than that.
There's no tachometer, which isn't a great lack, although the SP could have had
markings on the speedo for shift points, as the Honda does.
The SP's electrics are six volt, presumably because
the battery is lighter and smaller and easier to tuck behind the panels. And the
headlight and taillight are bright enough without being the lasers you get with
12 volts and halogen bulbs. One minor thing, though, is that the
warning lights are dim, so dim the rider has to squint to be sure the neutral
light is on even on cloudy days. And one of the older riders got so tired of not
seeing the signal warning that he reverted to hand signals, just like in days
when blinkers were optional and batteries all went dead.
Tools and papers live in a plastic box bolted to the frame below the left side
of the rear fender, again like brands H and Y. The lid of the box is rubber and
it seemed to seal well and stay put. Not quite the same design as Honda's, but
because we've lost more than one set of Honda tools and papers when the lid
flapped open in the woods, we never did
trust this box, despite not having it come open.
The SP comes with passenger pegs and one of those
darn straps at midseat. Somehow it was removed for the photos and never got
re-installed. Somehow. The fork lock is on the forks, not part of the switch on
the bars, but because the lock is easily reached with the bars at full left, the
location was no problem.
The SP250 doesn't match Suzuki's usual profile, which is giving the customer a
bit more bike for the money. The road models, for instance, are usually larger
and more roomy than their class competition.
The SP, though, is a bit smaller. This isn't bad and it gives a choice between
the 250 and 500s, just as Yamaha does and Honda doesn't do as much.
For instance, test weights:
Suzuki SP250 ...................273 lb.
Yamaha XT250 .................267 lb.
Honda XL250R.................285 lb.
Kawasaki KL250................293 lb.
And seat height:
Kawasaki ..:....................33.0 in.
Some of the differences are more er, different than others, and none are
critical, but the Suzuki's total is the smallest.
And it feels the smallest. Also unlike the other Suzukis, the SP has the seat
closer to the bars than average, so it feels short. The bars being close and
wide give lots of leverage.
The SP turns quickly and in traffic reacts to the
edge of darting back and forth. This was a puzzle for a while because it tracks
fine, steers even better and the actual balance is so good the rider can
practice coming to a stop and staying upright for a second or two, which led to
the conclusion that the rider is feeding the steering more input than is needed
Minus, the seat slopes forward and makes sure the rider is right up there on the
tank with arms outstretched. And the seat is narrow and square, yeah for the
third straight month we have us a motocross seat, the kind that's fine as long
as you don't sit on it. We have surrendered in that we no longer expect flip-up
seats, handy though they were, but this doesn't mean seats for sitting couldn't
be wider and more rounded and liveable all day. Which the SP's isn't.
The engine is mildly tuned, under less stress that
is, and it idles and pulls well. What it doesn't have is power. City traffic is
no worry but on the highway the engine sounds busy at more than 60 mph and if
there's a headwind or slight upgrade the rider is surprised to turn the throttle
and discover it's already tun will go.
The SP250 owner will proles! Ihc national speed
limit on principle only because 55 is the SP's natural cruising speed. It's not
being overworked faster than that, exactly, it's just that there's not ; much
left. (Not that anybody would ever try such a thing, but the SP will lose to the
XL and XT at the drags.)
Is that criticism? No. The SP runs well and runs fast enough and is economical,
it just isn't very fast and that's a fact.
Because the SP was a nifty city scooter, and we all know dual-purpose bikes are
compromised, it was rewarding to learn that the SP is also a good dirt bike.
It climbs the hills it should climb and it steers
astonishingly well. Front digs in and around she goes. The forks and rear shock
are nicely tuned to each other, they are soft enough in ruts and small dips
although neither end likes stutter bumps much, and when the suspension does
bottom out it's the bike's way of telling you you're about out of power and
traction anyway. The IRC trials tires float on sand and grip rock, sorry the
rains have quit so we can't say they slip in the mud although these tires always
have on all other dual-purpose models of our acquaintance.
One flaw is that the forward seating
Suzuki's new 250 Single is slightly oversquare, has four-valve head and single
overhead cam. Exhaust pipes are tucked away from rider's legs. Oil filter at
right front is easy to reach.
Tools and papers stow in plastic box below left side
of rear fender. Dangling end is the strap to retain the cover, except that the
strap fell out and the cover stayed in place.
Short lever in front of clutch lever opens exhaust valves during compression
stroke. Lever clicks off and piston is in the right position for easy one-kick
Lurking below the top rocker for the Full Floater suspension is the shock. The
shock works, the system works but the shock is nearly impossible to service. and
lack of punch keep the front end down unless the rider has planned to lift it.
The option of powering the front wheel up for a sudden dip isn't there.
Not quite a flaw was that the rear shock faded after
an hour of riding as fast as the SP would go and the back began hopping and
swapping in the whoops. This isn't as bad as it sounds because the SP was in
company with the DR250 and a Husqvarna 250WR at the time; the fade resulted from
demands beyond the call of duty and the SP is not an enduro bike.
In sum, the SP250 is good work and a welcome addition to the class.
Source Cycle Guide 1982