Muffler - Keefer, Inc. Tested

FMF 4.1 Muffler System (2021 KTM 250 SX-F)

My son and I have been going back and forth on mufflers for his KTM 250 SX-F and have went though about three until we settled on the FMF 4.1. We have tried the HGS (which was good), a Yoshimura, as well as a Pro Circuit system, but for his riding style and what he…

ByKris KeeferJune 7, 20210Comments

Bike Brands Bolt-Ons Exhaust Kawasaki KiT Performance

Yoshimura RS-12 Stainless Muffler System (2021 Kawasaki KX450)

The stock 2021 Kawasaki KX450 is pretty damn good machine, but that muffler looks atrocious right? We called up on Yoshimura to see if we can get a more attractive aftermarket muffler system that is actually better than the stock system. I will say that the stock KX450 muffler system works pretty damn well, but…

ByKris KeeferMarch 29, 20210Comments

Bike Brands Bolt-Ons Exhaust KiT KTM Performance

HGS Exhaust System For 2021 KTM 250 SX-F

Something that most riders (including me) may not see a lot of in the states is HGS exhaust systems. HGS is a Netherlands based company that has been making exhausts since the early 90s and are mostly popular among European club riders and of course many factory supported MXGP teams. I had the chance to…

ByKris KeeferFebruary 8, 20210Comments

Bolt-Ons Exhaust KiT Performance

DR.D Stainless Full Muffler System

By: Michael Allen And Kris Keefer It’s no secret that Doug Dubach knows Yamahas. That being said, after years of testing for Yamaha Doug started Dubach Racing Development where he builds finely tuned exhaust systems for other major motocross models. However, this isn’t one of those “other” motorcycles and we wanted to take that atrocious…

ByKris KeeferJanuary 14, 20210Comments

Bike Brands Bolt-Ons Exhaust Honda KiT Performance

Yoshimura RS-9T Stainless Full System (2020 Honda CRF250R)

The 2020 Honda CRF250R is much better off the bottom end than the 2018-2019 versions, but we wanted to test the latest full stainless Yoshimura RS-9T to see if it helped the stock Honda’s engine character at all. We were specifically looking for a little more RPM response and pulling power because the Honda is…

ByKris KeeferJune 10, 20200Comments

Bike Brands Bolt-Ons Exhaust Honda KiT Performance

Akrapovic Evolution Muffler System (2020 Honda CRF450R)

This is embarrassing, but I am going to be completely honest here… I think about the Honda CRF450R a lot. More than other machines. I mean I will literally wake up in the middle of the night and think of things to test in order to try and make the Honda chassis calm down a…

ByKris KeeferNovember 5, 20190Comments

Bike Brands Bolt-Ons Exhaust Kawasaki KiT Performance

Yoshimura RS-4 SS/AL Full Muffler System For 2019 Kawasaki KX450

By: Dominic Cimino Any of you that stay up to date with us here at Keefer Inc. are aware that I really enjoy riding the 2019 KX450. Like I really enjoy it. Maybe it is because we have the chassis and suspension dialed in just for me or maybe it’s just because the bike is…

ByDominic CiminoMarch 19, 20190Comments

Bike Brands Bolt-Ons Exhaust Honda KiT Performance

Yoshimura RS-9T Full Titanium Sytem For 2019 Honda CRF250R

It’s no secret that the Honda CRF250R is still lacking some bottom to mid range power when compared to the other competitors in the 250 class in 2019. Seeing as how I’ve been logging some hours on this machine as of late, I decided to test the full Yoshimura RS-9T titanium system to see if…

ByKris KeeferJanuary 1, 20190Comments

Bolt-Ons Exhaust KiT Performance

Pro Circuit Ti-6 Pro Titanium Muffer System

The 2019 Yamaha YZ450F won the Keefer Inc. Testing shootout this year because it has all tangibles that are needed to let a rider go fast on the track with the least amount of work. I am a fan of the stock muffler system on the 2019 YZ450F, but was looking for a full system…

ByKris KeeferNovember 20, 20180Comments

Bike Brands Exhaust KiT Performance Yamaha

Dubach Racing (DR.D) 2018 Yamaha YZ450F Slip-On Muffler

Before I start this review I am going to go on a little rant here, so bare with me. Mufflers are always a hot topic when it comes to horsepower, especially when you get a new bike. I know a lot of riders out there get a muffler system before they even ride their new…

ByKris KeeferFebruary 1, 20180Comments

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