DRZ/KLX125 Frequently Asked Questions
Note: Some of the items discussed in this FAQ are no longer available. This
information has been left online for historical reasons and to assist current owners of these now
discontinued items. If any of these parts are still available (new, used, or otherwise), they will
be listed on our product pages. To see all product listings for the this model click
Our BBR Product Identification section has more information about older products from our past.
Will your parts fit the DR-Z/KLX125 and DR-Z/KLX 125L?
Yes, all our parts will fit the 125 and 125L. The only difference between these
two bikes is wheel size, front disc, rear sprocket size (51 verses 57 for the L
model), and spring rates. Everything else--frame, engine, seat, tank, body work,
etc. is the same. The KLX and DR-Z are identical except for the color of the
What is the biggest problem with the stock DR-Z/KLX125?
It is probably a toss up, but the stock fork springs are so soft that the bike
is almost unridable. We have fork and shock springs available now. Second
biggest problem is with the stock exhaust system. It is totally corked up and
makes the bike really slow. Our exhaust system makes a huge performance
difference. The third biggest change is the carb kit. The ports on the
DR-Z/KLX125 are really big. The stock carb is simply too small.
What about the shock?
The stock spring is pretty soft on the shock too. It isn't as far off as the
fork springs but it is soft. The linkage ratio is actually pretty good. In fact,
with the right spring the rear suspension can be really good (for a small
production 4-stroke bike).
Is the DR-Z/KLX125 motor all new?
No, this motor has been around in one form or another for years. The LT125,
LT160, LT185, LT230, DR100, DR125, DR185, DR200 and others have all used some
version of this same motor. The motor is a little on the heavy side, but that
probably makes it more durable.
How big can I bore/stroke the DR-Z/KLX125?
How big do you want to go? The right combinations of
cranks/cylinders/pistons/heads from the various incarnations of this motor
should get it pretty big (at least 185cc). Remember that most 4-stroke mini-bike
races have a displacement limit (usually 150cc) and the bigger race events will
likely start checking more closely. We offer a bore-in piston (no sleeve
required) that will be race legal for these events. This kit makes a huge
increase in power.
What gearing should I run?
BBR recommends the stock gearing, which is 14/57 (L-Model), for most
applications. For tighter tracks try a 58, and wide open tracks a 56.
How much horsepower does the DR-Z/KLX125 have?
The DR-Z/KLX125 has slightly more than 7 horsepower stock at the rear wheel on a
DynoJet 200. Like the TT-R125, basically, if you're in shape, you can run a
little faster than the bone stock DR-Z/KLX125 will go.
Does BBR sell an O-Ring chain for the DR-Z/KLX125?
BBR does not recommend using an o-ring chain on a 7-horsepower bike unless you
are constantly riding under water. We run the DID ER Gold Series chain on all of
our race bikes and carry them in stock.
What can be done for to help the terrible carburetion on the DR-Z/KLX125?
Short of switching to our 26mm carb kit, here are some changes that we made. The
carburetor on the DR-Z/KLX125 is almost identical to the carb on the TT-R 125.
The needle on the DR-Z/KLX125 is fixed and doesn't allow adjustment. We had good
luck changing to the TT-R 125 needle (that does allow changing the clip
position). That was our single best modification for the stock carb. See
your local Yamaha dealer to purchase the TT-R125 needle and clip.
How fast does the DR-Z/KLX125 go?
Not very fast. That's why it's so stinkin' fun to ride. We do not measure top
MPH of any motorcycles. We don't really care. In motocross, it isn't how fast it
goes, but how quickly you get there.
What's the difference between the BBR exhaust system and all the rest?
BBR uses a stepped, tapered header which allows for both bottom-end torque and
top end over-rev-the best of both worlds. Most of our competitors use a straight
header; this results in a one-dimensional powerband, all top end or all bottom
end. Extensive testing with the tapered design allowed us to come up with an
exhaust system that both the secretary and Lance Smail can agree on. Why don't
the other guys use this setup? Because it's expensive to do it right. The tapers
and the quality of the materials used on the BBR pipes are not cheap, but you
get what you pay for. Basically, by bolting on the BBR exhaust system, you are
widening the power spread considerably, cutting down on shifting and letting you
ride a gear higher.
What about the disc-style exhaust systems?
The disc setups work pretty good, but you have to run so many discs to get
modern-day power characteristics (high over-rev) that it defeats the purpose and
ends up being louder and heavier than is necessary. An aggressive rider will
beat the disc-style into pieces because of the extra weight and number of parts
involved. You're not going to see professional motocross racer win a national with a
disc-style exhaust system. The 1980s are over.
How much does the BBR exhaust system weigh and how loud is it?
The BBR exhaust system weighs in right at 4 pounds, which is 2 ½ pounds lighter
than stock. Most of our competitors' pipes were one to one and a half pounds
heavier than ours. Our exhaust produces 96 decibels (measured at 20" from the
outlet at a 90 degree angle, as per AMA requirements) while stock is about 92.
Our exhaust is noticeably louder than stock but not ridiculous. We have
neighbors too. Unfortunately, power and sound go hand-in-hand-don't let anybody
tell you different. You can also order the BBR quiet core ( 220-BBR-1004 $39.95
) and run the trick fluted end cap.
Is the DR-Z/KLX125 better than the TT-R 125?
This is a tough question. Stock the TT-R is probably a better bike. The fork
spring are so soft on the DR-Z/KLX125 that it is hard to ride. With minor
modifications (fork springs, shock spring, exhaust) the DR-Z/KLX125 is probably
better than an equivalently modified TT-R 125. When both are extensively
modified it is hard to say which is better. We've only just begun to modify the
DR-Z/KLX125 and we have several years working with the TT-R 125. Ask again next
Is my DRZ/KLX legal in the mini or super mini class?
Every track and sanctioning body is different. Contact your local event
promoters or AMA district representatives to find out.
What are the benefits of BBR triple clamps?
The BBR upper triple clamp allows the fork tubes to be slid down 1" which raises
the front of the bike. It also grabs a larger surface area of the fork tube
which helps reduce fork flex. BBR offers the clamps in both standard and oversize
handlebar mounts, and we have a wide variety of handlebar bends and colors. The
bar mounts are two-way adjustable to customize the rider compartment. In
addition, the bar mounts are taller.
What will BBR fork and shock springs do for my DRZ/KLX?
BBR fork and shock springs are 30% stiffer than stock. BBR tested a wide
variety of spring rates and settled on these as the best all-around rate for the
DR-Z/KLX125, regardless of rider weight. The stiffer springs hold the
DR-Z/KLX125 up into the softer part of the travel and help to keep it from
bottoming. BBR's springs are of the highest quality and will not sack out. BBR
recommends using them as a set.
Will the RM 80 wheels/shock/swingarm/rear disc/ fit my DRZ/KLX?
No. With a bunch of modifications it is possible, but we do not offer this
I broke the rear hub on my DRZ/KLX125. Do you have a replacement?
No. This is super common with this bike. We do not have a "disc brake kit" or
anything else to fix this problem. Your best bet is to buy a new hub from you
Suzuki or Kawasaki dealer and then run heavy duty spokes (available from
Buchanan Spokes at www.buchananspokes.com). Make sure you keep those spokes
Will the DR-Z/KLX125 motor bolt into a YZ 80/CR 80/RM 80 frame?
No, but a BBR complete aluminum frame kit starts at $2999 and a rolling chassis
starts at $6500. These kits allow you to use all the 1996 and newer CR
What is a BBR cradle kit?
The cradle kit is a skid plate that ties the frame tubes together and helps to
prevent frame stretch and, in a worst case scenario, engine damage. It also
protects the engine cases from rock damage. The BBR engine
cradle is made from heat-treated 6061 aluminum and anodized gold.
What fork oil should I run at what level with the BBR fork springs?
BBR recommends running the stock 10w fork oil at the stock level, which is 130mm
or 5.1" from the top of the tube with the fork compressed. For faster or heavier
riders, try 15w at 4.8" from the top.
Should I run a flat slide carb on my TTR/XR/DR-Z/KLX125?
If you enjoy driving to your local dealer to buy jet after jet in a futile
attempt to get rid of the big flat spot, then this carb is for you. If you
prefer your bike not to idle or start easily and enjoy spending
more time jetting than riding, then you should install the flat slide carb.
The BBR guys finally found a use for the flat slide carb:
What should my suspension sag be set to with BBR springs?
We recommend you set the sag at about two inches. Adjust the sag to rider
preference for how quickly you would like the bike to steer. Note that
tightening up your shock preload will not (significantly) stiffen the rear of
the bike. It should be used to adjust the ride height of the bike.
Where can I get different colored plastic for my DR-Z/KLX125?
No aftermarket company currently makes plastic for the DR-Z/KLX125. The only
option for replacement plastic is the OEM plastic available from your Kawasaki
or Suzuki dealership.