Until recently, a Kawasaki Ninja 400 Exhaust wasn’t something that I was interested in. You see, I bought my Ninja 400 as a backup bike to my Yamaha MT-09 SP, and its primary function was to be a fun little back-road motorcycle.
I quickly fell in love with the Ninja 400 and began using it for more than short trips on Southeast Pennsylvania Back Roads. The more I rode it, the more I felt like something was missing. The stock exhaust was just too quiet.
This was when I began to toy around with the idea of a Ninja 400 Exhaust. I hit the internet and began doing some research – what I wanted was an exhaust that didn’t break the bank or require additional modifications to make the motorcycle run well.
I found no shortage of slip-on exhaust options, but I couldn’t bring myself to spend $500 to make my Ninja 400 sound more aggressive. I was about to pass on the idea when I received a surprise email from Wyatt Coffman of Coffman’s Exhaust Systems.
Wyatt explained that he came across my WaltInPA Instagram Account
and 1,000 Mile Review of the 2023 Kawasaki Ninja 400. He liked the content that I was producing and proposed a partnership. He offered me a free Coffman’s Shorty Exhaust in exchange for a product review. The timing of Wyatt’s email was perfect, and I was happy to take him up on his offer.
Table of Contents
About Coffman’s Exhaust Systems
Coffman’s Exhaust Systems is based out of Ukiah, California, where they produce a variety of exhaust options for the motorcycle industry. Their Coffman’s Shorty Exhuasts are proudly made in the USA and sold directly to consumers through their website.
Because Coffman’s Exhaust Systems manufacture its products in-house, it allows them to maintain budget-friendly pricing and high-quality standards. Their objective was to produce a quality product at a price that the average consumer could afford – without having to spend additional money tuning their motorcycles for performance gains.
Before entering the Sportbike industry in the 2000s, Coffman’s Exhaust Systems was known for their Jetski Performance Exhausts.
Construction
Coffman’s Shorty Exhaust Pipes are made from 304 stainless steel tubing that is CNC machined and mandrel bent with tig welded joints. The Stainless Steel Pipes are ceramic coated in black. Exhaust tips are aluminum and available in several color options.
Each exhaust comes pre-installed with a removable CNC machined db-killer (baffle) retained inside the tip through the highest quality high-temp silicone O-Ring, spacer, and snap-ring. Exhausts include a large perforated core encompassed by replaceable packing assisting heat management and sound suppression.
Exhaust Tip Options
The Coffman’s Shorty Exhaust is available in six different color options. They can be purchased with a Black Exhaust Tip, Polished Aluminum, Anodized Gold and Blue, and Powder Coated Green and Red.
For my Kawasaki Ninja 400 Exhaust, I selected the Coffman’s Shorty with a Kawi Greem Exhaust Tip. The color match to the 2023 KRT Edition Ninja was very close and matched the bike beautifully.
Installation
The installation process for replacing the Kawasaki Ninja 400 Exhaust is straightforward. Removing the stock exhaust and installing the Coffman’s Shorty only takes a few minutes; before you know it, you’re ready to ride.
Installation requires the following tools, and the video below will guide you through the process.
- 10mm Socket
- 12mm Socket
- 12mm Wrench (Optional)
- 5mm Allen/Hex
- Torque Wrench (9 ft-lbs)
Sound
The Stock Kawasaki Ninja 400 Exhaust is quiet and comfortable for long rides. It doesn’t drone in your helmet and leave you with a headache at the end of the day. Despite its positive aspects, it leaves something to be desired when riding through twisty back roads.
This is one area where Coffman’s Shorty Exhaust shines. It dramatically increases the exhaust sound and gives it a throaty note that comes alive at high rpm. I find that the sound makes me feel more connected to the moment.
Even though the exhaust is much louder than stock, I don’t find it obnoxious. At cruising speeds of 65mph in sixth gear, it settles down and is about as loud as typical wind noise in my helmet. It springs back to life during downshifting or hard acceleration.
Performance
The Coffman’s Shorty Exhaust is not designed to be an out-of-the-box performance upgrade to your Kawasaki Ninja 400. It is meant to replace your stock exhaust for a cleaner look with a much more aggressive sound. No tuning is required to make your motorcycle run properly in this configuration.
If you decide that you want to increase the performance of your Ninja 400, the baffle and internal packing on the Coffman’s Shorty can easily be removed. This will open up the exhaust and allow it to be free-flowing. Additional tuning using an ECU Flash or Fuel Management System is advised when running an open can.
Conclusion
As I write this article, I’ve lived with Coffman’s Shorty for over a month and find it an excellent addition to my 2023 Kawasaki Ninja 400. While it offers no significant performance upgrade, the added sound is awesome. The throaty growl makes shifting and winding through the gears even more fun!
An unexpected benefit of swapping out the stock Ninja 400 Exhuast is that the Coffman’s Shorty is significantly smaller and lighter. When moving around on the bike, my right boot no longer hits the OEM exhaust heat shield.
As I mentioned in my First Impressions Video (embedded at the top of this post), I always wear earplugs when I ride. My longest ride with Coffman’s Shorty has been nearly four hours, and in all that time, I never developed a headache from the sound.
Ultimately, Coffman’s Shorty was the perfect Ninja 400 Exhaust for me. It provides me with added sound without tuning for proper performance. For less than $300, I think this is a fantastic upgrade for anyone looking to make their Kawasaki Ninja 400 sound more aggressive.
Independence Day Edition
One minor complaint regarding Coffman’s Shorty Exhaust is that the branding is a little in your face. From a distance, the red lettering on the black ceramic coating jumps out at you. This is great for brand recognition, but I’d prefer it be more discreet and blend into the exhaust.
A great example of a seamless branding aesthetic is the Independence Day Edition – available June through August 2023. It ditches the red lettering and replaces it with an American Flag. This limited edition Coffman’s Shorty Exhaust looks fantastic, and I’d love to see it as a standard offering.
Buy a Coffman’s Shorty Exhaust
If you want to purchase a Coffman’s Shorty Exhaust for your motorcycle, you can do so through the Coffman’s Exhaust Systems Website. Their “Find Your Model” menu will allow you to quickly and easily filter results based on the manufacturer of your motorcycle. If your model isn’t listed, they also sell Universal Exhausts that can be used on various models.
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