Exhaust – Keefer, Inc. Tested

Yoshimura RS-12 Stainless Muffler System (2026 Honda CRF250R)

Installing the new stainless Yoshimura RS-12 full system took me less than 20 minutes and the instructions were very detailed. All of the parts that came inside the box fit perfectly and it was easy enough that my novice mechanical skills could install it! In my opinion, Yoshimura is one of the highest quality exhaust…

ByKris KeeferOctober 20, 20250Comments

Bike Brands Bolt-Ons Exhaust Hard Parts Kawasaki Performance

2025 Kawasaki KX250 Mods That Work

The 2025 Kawasaki KX250 is a lot different feeling on the track when comporting it to the 2024 version. The 25’ KX250 has a smoother engine character down low and is a little stiffer in the chassis. On the dyno the numbers between the 24 and 25 KX250 actually favor the new bike but on…

ByKris KeeferJuly 7, 20250Comments

Exhaust Hard Parts Performance Triumph

FMF 4.1 Muffler System For Triumph TF-450 RC Edition

The Triumph TF450-RC Edition is the newest 450 motocross machine, but I have had A LOT of time on this bike in stock form and with some mods done like this FMF 4.1 muffler system. In stock form the TF450-RC Edition has a smooth low end power with a wide mid to top end but…

ByKris KeeferJune 30, 20250Comments

Bike Brands Bolt-Ons Exhaust Hard Parts Performance Suspension Yamaha

Top Chassis/Engine Mods For 23-25 Yamaha YZ450F

ByKris KeeferApril 22, 20250Comments

Bike Brands Bolt-Ons Exhaust Hard Parts Kawasaki Performance

Top 5 Mods For The 2025 Kawasaki KX250

ByKris KeeferApril 9, 20250Comments

Bike Brands Bolt-Ons Exhaust Hard Parts KTM

2025 KTM 250SX Pro Circuit Works Pipe and Shorty Silencer

There is something about a crisp sounding two stroke. I am not a huge two-stroke rider but to me the best thing about a two-stroke is that crisp/over-rev sound that happens right before you land from a jump! That gets me going! But what about going to an aftermarket pipe/silencer? Does it make the bike…

ByKris KeeferMarch 11, 20250Comments

Bike Brands Bolt-Ons Exhaust Hard Parts Kawasaki

Pro Circuit Ti-6 Muffler System (2025 KX250)

Kawasaki has an all new KX250 and Pro Circuit just recently came out with their latest Ti-6 version for the new green machine. With airbox changes to the 2025 version as well as a different cylinder head, this forced Pro Circuit to come up with a new headpipe and muffler. We have put time on…

ByKris KeeferDecember 16, 20240Comments

Bike Brands Exhaust Hard Parts Motocross

FMF 4.1 Ti Muffler System For Triumph TF250-X

The Triumph TF250-X is the newest 250 motocross machine so that means we haven’t had a lot of time with aftermarket mufflers yet until now. In stock form the TF250-X has a smooth low end power with a wide mid to top end but maybe lacks a little bit of excitement on low end (with…

ByKris KeeferDecember 9, 20240Comments

Bike Brands Bolt-Ons Exhaust Hard Parts KTM Performance

Why A KTM 250 SX-F FMF Megabomb Headpipe Is Better On A KTM 350 SX-F

I originally posted a photo of a KTM 250 SX-F FMF Megabomb headpipe mated to a KTM 350 SX-F 4.1 FMF muffler and my DM’s flooded with questions. Why does it do? Why stick the 250 headpipe on the 350? Normally when you purchase an aftermarket muffler system you usually get a smoother roll…

ByKris KeeferOctober 20, 20240Comments

Bolt-Ons Exhaust Hard Parts Kawasaki

Yoshimura RS-12 Stainless System (2024 KX450)

Written By: Eddie Laret/Kris Keefer We all know Kawasaki left a lot of room for improvement on the muffler side of things on the 2024 Kawasaki KX450. We have tried a number of mufflers to help increase the low end torque and have been happy with a couple. The latest muffler we tested was…

ByKris KeeferAugust 6, 20240Comments