Suzuki RMX250S
Suzuki RMX250S | |
Manufacturer | |
---|---|
Production | 1991 - 1993 |
Class | Enduro |
Engine | Two stroke, single cylinder, liquid cooled |
Compression ratio | 9.9 - 9.2 - 8.1:1 |
Horsepower | 50.96 HP (38.0 KW) @ 9000RPM |
Torque | 33.93 ft/lbs (46.0 Nm) @ 7000RPM |
Fuel System | Mikuni TM38SS carburetor |
Ignition | Suzuki PEI |
Spark Plug | NGK BR9EV |
Transmission | 5 Speed constant mesh |
Suspension | Front: Inverted telescopic, pneumatic/coil spring, oil dampened, 21 way compression dampening, 21 way rebound dampening Rear: Link-type, spring preload fully adjustable, 18 way compression dampening, 21 way rebound dampening |
Brakes | Front: Single disc Rear: Single disc |
Front Tire | 80/100-R21 51M |
Rear Tire | 110/100-R18 64M |
Wheelbase | 1,485 mm / 58.5 in |
Length | 85.98 inches (2184 mm) |
Width | 35.2 inches (894 mm) |
Seat Height | 955 mm / 37.6 in |
Weight | 108 kg / 238 lbs wet_weight = 115.0 kg (dry), |
Recommended Oil | Suzuki ECSTAR 10w40 |
Fuel Capacity | 11 L / 2.9 US gal / 2.4 Imp gal |
Manuals | Service Manual |
The Suzuki RMX 250S was a Two stroke, single cylinder, liquid cooled Enduro motorcycle produced by Suzuki between 1992 and 1993. Max torque was 33.93 ft/lbs (46.0 Nm) @ 7000 RPM. Claimed horsepower was 50.96 HP (38.0 KW) @ 9000 RPM.
Engine[edit | edit source]
The engine was a Liquid cooled cooled Two stroke, single cylinder. The engine featured a 9.9 - 9.2 - 8.1:1 compression ratio.
Drive[edit | edit source]
Power was moderated via the Wet, cable operated.
Chassis[edit | edit source]
It came with a 80/100 - R21 51M front tire and a 110/100 - R18 64M rear tire. Stopping was achieved via Single disc in the front and a Single disc in the rear. The front suspension was a Inverted telescopic, pneumatic/coil spring, oil dampened, 21 way compression dampening, 21 way rebound dampening while the rear was equipped with a Link-type, spring preload fully adjustable, 18 way compression dampening, 21 way rebound dampening. The RMX250S was fitted with a 11 L / 2.9 US gal / 2.4 Imp gal fuel tank. The bike weighed just 108 kg / 238 lbs. The wheelbase was 1,485 mm / 58.5 in long.
1992 Suzuki RMX 250S[edit | edit source]
The 1997 RMX 250S comes well-equipped right from your dealer, for either off-road racing and/or trail riding; perhaps even a bit over equipped. We're talking here about the EPA legal exhaust system that includes a clunky double-walled pipe and heavy, power sapping steel silencer/spark arrestor.
1993 - 1998 Suzuki RMX 250S[edit | edit source]
The 1997 RMX will likely be the final year of this, the first generation of the model line. Characteristic throughout that run, this year's RMX continues to provide a well suspended platform in EPA legal trim. Top racers will no doubt loathe the compromises to quietness, and the resulting added expense of aftermarket pipes, silencers and RM head gaskets.
Photos[edit | edit source]
Review[edit | edit source]
It's been some time since we here at Trail Rider had a chance to swing a leg over Suzuki's championship-winning RMX. Quite frankly, since the RMX has remained largely unchanged since its 1989 debut, it was hard to get excited about yearly refinements and BNGs. For 1996 however, Suzuki has done considerably more than improve an existing, albeit competitive off-road line. For one, the entire 1996 RM based line, including the RMX, have followed KTM's lead in the return to conventional slider forks. Fine twin chamber units are used on the RM, while the RMX gets a unique conventional slider cartridge-type fork.
To cut to the chase, this fork works good, at
least as good as the new Marzocchi units.
On top of that seemingly earth-shattering news
from Japan, front end changes are just the tip of the iceberg on the RM250. It
turns out, the '96 RMX lags along with minor updates to last year's engine,
while the '96 RM gets a truly new motor right down to the cases.
It used to be that when you wanted to hop up your
RMX, all that was required was a little browsing through the same year RM parts
fiche. This is not the case for Suzuki's '96 quarter-liter offerings, as you'll
have to revert to the '95 RM parts bin for help.
However, look for the '97 RMX follow suit with
the new motor that includes dimensional changes (longer stroke), cylinder reed
induction system (vice case reed), an improved water pump design that moves the
pump and impeller within the cases for better crash protection, completely
redesigned clutch actuation linkage and a fully removable subframe.
"Commence salivating"
Any way, enough history. The new fork is enough
to stir our interest, and with a little help from local dealer Taylor Toussaint
of Mt. Holly Suzuki/Kawasaki, we secured a fresh from the factory '96 RMX, and
carved out a test session with the aid of a couple of local test riders: enduro
wunderkind John Robbins and pro MXer/off-road hero Joel Dengler.
The '96 RMX comes well-equipped right from your
dealer, for either off-road racing and/or trail riding; perhaps even a bit over
equipped. We're talking here about the EPA legal exhaust system that includes a
clunky double-walled pipe and heavy, power sapping steel silencer/spark
arrestor.
Rounding out the annual RMX performance
strangling, the airbox is capped with a bulky cover/induction snout. Nothing new
here.
On a more positive note, the new conventional
slider front end is graced with bellows-type fork boots (while the RM comes with
roost guards), complete with plastic fork underhang guards, and a front disk
protector as well. Enduro goodies like a mechanical odo, a wide ratio five speed
transmission, heavyweight flywheel, plastic rear disk and caliper guards, an
o-ring chain, three gallon fuel cell, lighting coil, headlight and tail light,
leave woods hounds little to howl about. From a maintenance and reliability
viewpoint, zerk fittings are found on all rear linkage pivot points, and a new,
RM-esque, two ring piston graces the engine. Rounding out the package, cast foot
pegs that replicate (in looks, anyhow) expensive works pegs machined from billet
stock bolster this important rider interface. In a nutshell, this bike is
loaded.
The Test
For our riding session, we left the RMX totally
stock, and made no changes to jetting, suspension, or exhaust hardware.
The motor proved an easy starter, even in the 40
degree temperatures of late November. With the choke on, it maintained a steady
idle during warm-up, although it might have hinted of richness and the potential
to load up. Warmer temperatures would likely demand a turn of the airscrew or
otherwise leaner jetting, which should be no problem on the familiar Keihin PJ38
carb.
For initial suspension setup, the fork
compression adjusters were set at 13 clicks out from full hard and had an
advertised range of 18. Interestingly though, we counted the adjustment range
and only came up with 15 clicks. Similarly, fork rebound was set at 12 clicks
from full damping while the advertised 18 rebound detents conflicted with our 23
clicks measured. Out back, shock compression was set at 14 clicks out from full
hard (range 21 clicks advertised, 25 clicks measured) and shock rebound set at
12 out from full damping (range 21 clicks advertised, 26 clicks measured).
Unfortunately, we didn't remember to check the sag until out on the trail.
Afterward, when we did get around to measuring it, the sag (with our sorry,
middle-aged butts on the saddle), was found to be a soft 120mm. Had we had more
time, we would have liked to crank the sag down to something closer to 100mm and
go thrash some more. No doubt this would do nothing but improve what was found
to be already fine suspension action.
Without any hand protection other than the stock
hand guards, our tight woods work was severely limited. However, it was apparent
that this is where the '96 RMX would excel, with lively low end power and a good
linear power band. Of course, whenever the terrain opened up, the motor either
required incessant clutching or just signed off. The stock motor just plain
loses its breath at higher speeds in open country. Fortunately, the clutch pull
is hands down the lightest in the business. A credit to the Suzuki engineers,
it's amazing that a clutch pull this light doesn't lead to chronic slippage
problems.
After a very short period of riding the bike bone
stock, we made our only change of the afternoon, discarding the airbox lid. This
immediately improved motor response, especially in the transition from low to
mid range. Not to say that it is comparable with other 250cc enduro bikes in
this trim, but it does suggest that completion of the transformation (a.k.a.
delegalization) would leave few riders jonesing for more ponies. This well known
parts replacement drill includes an aftermarket pipe and silencer for more
midrange and top end, coupled with a switch to a thinner RM head gasket which
raises the compression ratio to boost low end bark. Everybody who races an RMX
does this switch, and it is a completely different bike with the
high-performance parts installed.
"The suspension set
up as above was most plush, down in the comfy chair range."
Initial compliance was such that the fork would
easily react to the smallest of bumps, roots or sticks. This made woods work a
cinch, allowing tree threading without fear of deflections. Despite this
apparent softness we could not bottom either end, even with Dengler showing off
his MX bag-o-air tricks. Likewise, the RMX managed sand whoops competently,
without any unwanted kicking or swapping, and proved to be plenty stable at
speed.
If we could cite one complaint, it was a slight
tendency to dive into turns. We attributed this to a little lightness on the
fork compression damping, perhaps compounded by the improper sag setting out
back. Surely a sag readjustment coupled with some fiddling with the fork
compression damping would take care of nearly any complaints. Bulkier riders,
however, might have to consider heavier springs, whereas lighter riders might
find everything just fine. If you're familiar with KTM's Marzocchis, the RMX
fork is much more compliant than that fork during the initial hit, yet retains
significant bottoming protection. Bottom line, the new conventional slider fork
works great, and are well matched to the rear shock action. No doubt, the '96
RMX will provide an able working package that few riders could complain about.
Wrap It Up
The '96 RMX will likely be the final year of
this, the first generation of the model line. Characteristic throughout that
run, this year's RMX continues to provide a well suspended platform in EPA legal
trim. Top racers will no doubt loathe the compromises to quietness, and the
resulting added expense of aftermarket pipes, silencers and RM head gaskets.
However, any level-headed rider would agree that quiet should be the default,
rather than the other way around, in today's political climate. If you want to
leave it stock, the '96 RMX provides spirited performance, more than adequate
for trail riding, that should prove plenty competitive in nearly all novice or
intermediate class contests. Either way, the RMX can be easily molded into a top
performer.
Source
Specifications[edit | edit source]
Make Model | Suzuki RMX 250S |
---|---|
Year | 1991-92 |
Engine Type | Two stroke, single cylinder |
Displacement | 249 cc / 15.2 cu in |
Bore X Stroke | 67 mm x 70.8 mm |
Compression | 9.9 - 9.2 - 8.1:1 |
Cooling System | Liquid cooled |
Lubrication System | Fuel/oil premix of 20:1 |
Induction | Mikuni TM38SS carburetor |
Ignition | Suzuki PEI |
Starting | Kick |
Spark Plug | NGK BR9EV |
Max Power | 38 kW / 51 hp @ 9000 rpm |
Max Torque | 46.6 Nm / / 4.75 kgf-m / 34.4 lb-ft @ 7000 rpm |
Clutch | Wet, cable operated |
Transmission | 5 Speed constant mesh |
Final Drive | Chain |
Front Suspension | Inverted telescopic, pneumatic/coil spring, oil dampened, 21 way compression dampening, 21 way rebound dampening |
Rear Suspension | Link-type, spring preload fully adjustable, 18 way compression dampening, 21 way rebound dampening |
Front Brakes | Single disc |
Rear Brakes | Single disc |
Front Tire | 80/100 - R21 51M |
Rear Tire | 110/100 - R18 64M |
Dimensions | Length: 2185 mm / 86.0 in Width: 895 mm / 35.2 in Height 1255 mm - 49.4 in |
Wheelbase | 1,485 mm / 58.5 in |
Ground Clearance | 360 mm / 14.2 in |
Seat Height | 955 mm / 37.6 in |
Dry Weight | 108 kg / 238 lbs |
Fuel Capacity | 11 L / 2.9 US gal / 2.4 Imp gal |