Yoshimura RACE 14301BC350 User manual

RESEARCH&DEVELOPMENT OF AMERICA, INC.
www.yoshimura-rd.com
5420 DANIELS STREET STE A, CHINO CA 91710 · [phone] · [phone] · FAX [phone]
NOTE: IN THE STATE OF CALIFORNIA, IT IS ILLEGAL TO MODIFY THE EMISSION CONTROL SYSTEM, WHICH INCLUDES THE CARBURETORS OF ANY VEHICLE.
You must know how to remove and replace your stock exhaust in order to install this product
otherwise have it installed by a professional mechanic. Keep all stock parts from your existing
system as some components may be necessary to install your new Yoshimura exhaust depending
on the application. Read through all instructions before beginning installation. Exhaust system can
be extremely hot. Let motorcycle cool down before beginning installation. Always wear hand and
eye protection and take precautionary measures to avoid injury.
RACE SERIES
14301BC350 (SS/AL)
Kawasaki
Qualified Manufacturer Declared “Modified Part”
Race Series systems are:
• NOT CARB/EPA tail-pipe emissions compliant.
• NOT street legal.
• For “Closed Course Competition” use only.
FOR CLOSED COURSE COMPETITION ONLY; NOT INTENDED FOR STREET USE
RS-2 Stainless Steel Slip-On
2009~2020
KLX250 2021~2023 KLX300

2
Assembly Diagram
No. Item Description Qty.
1 14301-435 Yoshimura Tailpipe 1
2 143002C350-RMA Yoshimura Muffler Assembly 1
3 Z1022 Muffler Grommet 1
4 ALS-029 Aluminum Spacer 1
5 M8X35H 8mm x 35mm Flanged Hex Head Bolt 1
6 8MMWASHERL 8mm Large Washer 1
7 RACE-SPX-2 Small Exhaust Spring 2
** 11061-1055 Exhaust Gasket 1
** M12X8H O2 Sensor Plug 1
** 347PLUG Muffler Wash Plug 1
** ST-200 Spring Puller Tool 1
** 17029 Sticker Kit Sheet 1
** Not shown in diagram.
1
2
34
5
s
6
S = Stock
7
7

1. Remove the three right side panel bolts are
carefully remove right side panel.
2. Loosen the exhaust clamp between header and
muffler tailpipe connection.
3. Remove O2 sensor from the stock muffler for
2018 model.
3. While securely supporting the stock muffler
assembly, remove the three bolts securing
muffler assembly to the frame and carefully
remove the stock muffler assembly.
Note: The stock exhaust gasket will be replaced
with one supplied in the kit. Remove
gasket from header.
Removal
3
CAUTION: Exhaust system can be extremely hot.
Let motorcycle cool down before
beginning installation. Always wear
hand and eye protection and take
precautionary measures to avoid
injury.
WARNING: Always properly support vehicle with
a stand and/or lift when servicing or
performing any work. Unstable
vehicles may present dangerous
conditions and may cause property
damage and/or personal injury.
NOTE: Read through all instructions before
beginning installation.
Installation
1. Install (No. 3) Z1022, muffler grommet into muffler
bracket.
2. Install (No. 4) ALS-029, aluminum spacer into
(No. 3) Z1022, muffler grommet.
3. Install 11061-1055, exhaust gasket over (No. 1)
14301-435, tailpipe inlet.
4. Install (No. 1) 14301-435, tailpipe into the stock
header outlet. Align tailpipe chassis mount
bracket to chassis mount and secure using the
stock bolt and washer. Do not torque at this
time.
Note: For 2018 model, re-install stock O2
sensor into tailpipe and torque to factory
specification. For 2009~2014 models,
install supplied M12X8, O2 sensor plug
into O2 snesor bung on tailpipe.
5. Install (No. 2) 143002C350-RMA, muffler
assembly onto (No. 1) 14301-435, tailpipe outlet
and align muffler bracket to muffler mount.
Secure muffler using (No. 5) M8X35H, flange
bolt and (No. 6) 8MMWASHERL, large washer.
Torque muffler mount bolt to 32 Nm (3.2 kg-m,
24 ft-lb).
6. Torque tailpipe chassis mount bolt to factory
specification.
7. Torque stock exhaust clamp between header
and tailpipe to factory specification.
8. Install (No. 7) RACE-SPX-2, small exhaust
springs between muffler and tailpipe connection
using ST-200, spring puller tool supplied in the
kit.
9. Before starting vehicle, check for proper
clearance between new exhaust system and
rear suspension (i.e. tire, swingarm, brakes,
rear shock, and etc.) If any problem is found,
please carefully follow through the installation
steps again. If problem still persists, please call
Yoshimura Tech Department at [phone] /
in CA [phone].
3
4
3

10. It is recommended that the muffler and tailpipe
be wiped down with rubbing alcohol to remove
oil and fingerprints. This will help prevent
tarnishing of the finish after the exhaust is
heated up.
Note: After starting vehicle, it is normal for new
exhaust system and muffler to emit
smoke until oil residue burns off.
4
Works Finish
Care & Maintenance
Before starting vehicle, clean pipe thoroughly using
a soft cloth and rubbing alcohol to remove any oil
and finger prints.
The color of the exhaust will change once the
system has gone through a heat cycle of 15
minutes or more. Color will vary depending on
lean/rich conditions.
Clean using a soft cloth and soap. Do not use
abrasive materials as it will scratch the surface.
Surface reconditioning services are available to
remove scratches and undesirable discoloration
due to extreme heat. Contact Yoshimura Tech
Department at [phone] / in CA (909) 628-
4722 for more information.

Dear Yoshimura Customer,
Congratulations and thank you for purchasing a Yoshimura Exhaust System. Over six decades of experience in research
and development, state of the art machinery, materials and craftsmanship of the highest quality all come together in a
product of exceptional quality and performance—in other words, this is the best thing you can put on your bike.
We strive to provide you with a product perfect in fit and finish. However, if you have any problems, please give us a
call. We have found that most fitment issues can be easily resolved by a conversation with one of our knowledgeable
and friendly staff. If the issue cannot be resolved this way, our warranty evaluation program may be the answer. Please
take a moment to review our recommendations for the care of your exhaust and our warranty information.
PLEASE NOTE: If you have any doubts about your exhaust: DO NOT START THE MOTORCYCLE! ONCE AN EXHAUST HAS
BEEN USED OR MODIFIED, IT CANNOT BE RETURNED FOR CREDIT OR EXCHANGE.
EXHAUST SYSTEM MAINTENANCE
Yoshimura Exhaust Systems require very little care and maintenance; here are a few tips:
1. Use mild car/motorcycle soap to clean the exhaust system—do not use any abrasives or degreasers.
2. Clean your exhaust with metal/stainless polish every 1-2 months to retain the luster and remove dirt and grime.
(DO NOT USE POLISH ON “WORKS FINISH” SYSTEMS)
3. Avoid contaminating exhaust surfaces when hot.
4. 4.Your exhaust system will change color (blue, magenta, purple, and/or gold) due to heat; this is normal.
5. Keep all clamps, bolts and other fasteners tight as exhaust systems are susceptible to vibration damage.
6. If you ride in coastal regions or areas that use salt to control ice and snow, wipe the exhaust down after it cools to
remove any possible salt residue, which can result in rusting.
7. If you are storing your motorcycle for the season, wipe the exhaust system down with rubbing alcohol before
storage.
8. Head pipes glowing (visible in normal light) may indicate an excessively lean condition that must be corrected.
CARBON FIBER:
Carbon fiber equipped exhaust components require special attention. The following addresses wear issues directly
related to carbon fiber:
1. Keep all clamps, bolts and other fasteners tight. Carbon Fiber is very susceptible to vibration damage.
2. Keep all chemicals and solvents away from the carbon fiber, as they will damage the finish.
3. High temperatures will cause the resin in the carbon fiber to break down. Visual signs such as an amber hue in the
resin may be early signs of heat damage to carbon fiber.
4. Upon seeing amber colored resin, discontinue use. The exhaust system needs to be inspected by a representative
from Yoshimura, for repack, and/or repair. Continued use will cause component failure.
STAINLESS STEEL:
Stainless Steel is not rust proof but is less prone to rusting, staining and pitting; but it is prone to oxidation like all
metals.
WORKS FINISH:
1. Works Finish exhaust systems should never be cleaned with abrasives or polishes.
2. Yoshimura recommends using “Bar Keepers Friend” cleaner to remove minor stains.
3. Surface reconditioning services are available to remove scratches and undesirable discoloration due to extreme
heat. Contact Yoshimura Tech Department at [phone] / in CA [phone] for more information.

RE-PACKING TIPS
To maintain maximum sound and engine performance the muffler packing will need to be replaced at some time during
the muffler’s life. Yoshimura recommends repacking your muffler at least once a year.
Failure to maintain the muffler packing may cause damage to the muffler and/or void the warranty. Regularly inspect
the muffler body for discoloration, cracks, rattling, or other signs of wear caused by depleted muffler packing. If muffler
packing is determined to be depleted or worn, a Yoshimura muffler re-pack kit is highly recommended to restore the
muffler to optimum maximum performance.
Yoshimura offers a 3-5 day turn around (plus transit time) to inspect and refurbish used and damaged mufflers.
For more information on muffler repacking please visit our website at: https://www.yoshimura-rd.com/pages/repack-
and-insert-chart
***PRO TIP*** Before you install your new muffler for the first-time log the weight in your Owner’s or Service manual
along with the current hours or mileage on your vehicle. When you are performing periodic maintenance on your
vehicle (like a tire change, or an oil change) you can remove your Yoshimura muffler from the vehicle and weigh it again.
Over time, the packing material inside your muffler will burn off with use, and the muffler will need to be repacked.
When the weight loses approximately 100 grams of the original weight, you should consider getting your Yoshimura
muffler repacked. You can order repacking kit or the parts to repack the muffler from the Yoshimura website, or
your local dealer. You can also contact the Yoshimura sales office and arrange to send in your muffler for the repacking
service too.
IMPORTANT TECHNICAL NOTE
Yoshimura recommends on all race exhaust systems, that all spring joints be safety wired. Recommended wire type
304/316 stainless steel with a .032” diameter should be used.
YOSHIMURA EXHAUST LIMITED WARRANTY
All Yoshimura R&D of America, Inc., exhaust systems carry a one-year limited warranty against defects in workmanship
and/or materials.
WHO IS COVERED?
This warranty is provided to the original purchaser of the exhaust system.
WHAT VOIDS THE WARRANTY?
1. Abuse, misuse, improper installation and/or modifications
2. Custom applications
3. No proof of purchase at the time of warranty. Claimant must provide proof of purchase (original receipt or invoice)
and a warranty authorization number (RMA) obtained from Yoshimura.
4. Finishes such as plating or painted surfaces with discoloration or rust due to inclement weather conditions, exposure
to salt, exposure to chemicals, or lack of maintenance by the customer are not covered.
5. International grey-market product purchased through a dealer/distributor not authorized for your country will not
be supported by this warranty.
EXTENT OF WARRANTY:
Any defective exhaust system properly returned to Yoshimura will be repaired or replaced by Yoshimura. Yoshimura is
not responsible for any other expense incurred by the customer under the terms of this limited warranty, nor is
Yoshimura responsible for any damages either consequential, incidental, special, contingent or otherwise; or expenses
or injury arising directly or indirectly from the use of the exhaust system. Any exhaust system returned to Yoshimura
must be sent at the customers expense along with the proof of purchase and warranty authorization (RMA). Yoshimura
reserves the right to determine whether the terms of the warranty, set out above, have been properly followed. In the
event that the terms are not followed this warranty is void. Yoshimura is the sole determiner of abuse, misuse,

installation errors and modifications—should any of these be found, this warranty is void. The duration of any and all
implied warranties are limited to the duration of the express warranty. All incidental or consequential damages are
hereby excluded. The warranty gives you specific legal rights and you may have other rights, which vary from state to
state. Some states do not allow the exclusion or limitation of incidental or consequential damages or limitations on how
long an implied warranty lasts, so the above limitations and exclusions may not apply to you.
If you have a fitment or other problem, or are missing a part, please double-check this trouble shooting guide first:
1. Reference your instruction sheet and double-check all drawings and instructions
2. Make sure muffler clamps are installed correctly (refer to instructions diagram). On many models, there is a right
and wrong way to install. Also verify part numbers on headers and tail pipe.
3. Always make sure to install spring-mounted manifolds and flanges on cylinder head prior to installing headers.
4. Always take time to examine problems in detail.
5. When all else fails, call our technical support line at [phone]. The technical line is open 9:00am – 4:30pm
Monday through Friday, Pacific Time. Please have the following information handy: Year/Make/Model of
motorcycle, date of purchase, place of purchase, batch dates and part numbers (found on header and tail-pipe
components).
6. Also, feel free to ask through online e-mail at [e-mail], or fax your question/problems to (909) 591-
2198.
To obtain technical information directly from Yoshimura, call [phone].