--- Dual CRF250 & All KTM250SXF Exhausts DO NOT Include Mid-Pipes ---
---"Sorry but this product does not qualify for the cash back program"---
COMES WITH 94dB Insert
FMF - Factory 4.1 Slip-On Silencer
The Factory 4.1 system was derived from our successful Factory 4. We developed a completely new system with an ALL NEW muffler design. The Factory 4.1 oval muffler is constructed from military grade titanium utilizing an angle cut end cap and offered in either a natural or anodized blue finish. The performance characteristics start with a formed tapered inlet leading into the muffler. The oval shape combined with the tapered inlet allows the muffler to be routed further forward without interfering with the frame, subframe, shock, rear wheel or brake. Our Factory Forward Engineering lowers and centralizes the machines center of gravity for improved handling without sacrificing silencer volume and durability. With it's new formed end cap, the muffler is less susceptible to damage. The modular exhaust port flange transmits less vibration reducing tension on the system. The all new angle cut end cap offers versatility and tunability with the optional Power Rings and Rev Tubes to alter power delivery. There is also a optional removable spark arrestor module for off-road applications. This slip on contains the muffler and mid pipe.
REVIEW SNAPSHOT®
by PowerReviews(based on 20 reviews)
Ratings Distribution
100%
of respondents would recommend this to a friend.
Pros
- Easy to use (13)
- Lightweight (12)
- Versatile (6)
- Durable (4)
- Tough (4)
Cons
Best Uses
- Racing (15)
- Off-road (11)
- Upgrade (5)
- Motorsports:
- Competitive cyclist (14), Casual rider (8), Motorcycle enthusiast (5)
Most Liked Positive Review
It's Good
It was a good buy. It gave the bike a bit more smoother power hit. But to really notice a difference you would need to buy the powerbomb or megabomb. A good buy though...Read complete review
It was a good buy. It gave the bike a bit more smoother power hit. But to really notice a difference you would need to buy the powerbomb or megabomb. A good buy though. It sounds awesome. A nice deep roar and the blue exhaust looks nice with the 2009 yz250f.
VS
Most Liked Negative Review
loud sound by FMF
easy to mount,light and nice,but makes too mutch noice !!!
easy to mount,light and nice,but makes too mutch noice !!!
Reviewed by 20 customers
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Displaying reviews 1-10
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Pros
- Versatile
Cons
- Difficult To Use
Best Uses
- Racing
Comments about FMF - Factory 4.1 (Slip-On):
difficult to connect mid pipe to headpipe
because of aluminum sleeve joint innert diameter
seems slightly narrow took me half a day sand papering also heat melted part of side pannel
still seems beeter than genuime slightly lighter
and quicker trottle respond
- Motorsports:
- Competitive Rider
Pros
Cons
- NA
Best Uses
- Racing
Comments about FMF - Factory 4.1 (Slip-On):
Cheaper then anywhere else by at least $90
Some places as dear as $300 more..
Perfect fit, fyi, the pic is the muffler and mid pipe. So 2 pieces come with it
- Motorsports:
- Casual Rider, Competitive Rider
Pros
- Durable
- Easy To Use
- Lightweight
- Versatile
Cons
Best Uses
- Off-Road
- Racing
Comments about FMF - Factory 4.1 (Slip-On):
sounds mean and adds power to the bottom end!
- Motorsports:
- Casual Rider, Competitive Rider
Pros
- Comes with quiet insert
- Durable
- Easy To Use
- Extra Power
- Lightweight
- LOUD
- Much better sound
- Shiny Attractively So
- Versatile
Cons
- Melts stock inicators
- Too Loud for road use
Best Uses
- Off-Road
- Racing
Comments about FMF - Factory 4.1 (Slip-On):
A great looking Muffler, easy to fit, nice sound although could be a bit too loud, mite need a more soundproof helmet. The quiet insert is a must if ur gunna ride it on the road. I fitted it with a powerbomb header and it really opened up the bike. 5th gear power wheelies are quite easy now on my 2011 wr450f. If you have stock indicators you will need to relocate them if u dont want them to melt off your bike.
- Motorsports:
- Casual Rider, Competitive Rider, Mechanic, Motorcycle Enthusiast
Pros
- Easy To Use
- Lightweight
Cons
Best Uses
Comments about FMF - Factory 4.1 (Slip-On):
Makes ay good sound to my 2011 yzf450 and ay little more bottom end power
Pros
- Easy To Use
Cons
- No spark arrestor
Best Uses
- Racing
Comments about FMF - Factory 4.1 (Slip-On):
Looks [*] and is a really nice pipe. I don't notice much of a difference but I have yet to jet my 09 kawi.
- Motorsports:
- Competitive Rider
Pros
- Easy Maintenance
- Easy To Use
- Lightweight
- Snug fit
Cons
Best Uses
- Long Rides
- Off-Road
- Racing
- Street
Comments about FMF - Factory 4.1 (Slip-On):
Great value for money. I bought this slip on complete with S/Steel Power Bomb header mainly to reduce weight on CRF450X. OEM system weights 4.63kg & this FMF system weights 3.0kg. Major weight saving considering where it is positioned on the bike. Pipe fitted together with a little persuasion, tight connection between mid & header pipes. Sounds like a 450 should. Not too loud & very thoaty. Will need minor adjustments to carby for best performance, but works great even with OEM jetting.
Pros
- Easy to install
- Powerful
Cons
Best Uses
- Off-Road
- Racing
Comments about FMF - Factory 4.1 (Slip-On):
Great sound note and installation process was a breeze. Good power gains down low
- Motorsports:
- Competitive Rider
Pros
- Easy To Use
- Great tone
- Lightweight
- Louder than stock
- Much more power
- Not too loud
Cons
- Must rejet the bike
Best Uses
- Off-Road
- Racing
- Upgrade
Comments about FMF - Factory 4.1 (Slip-On):
i used it with the fmf powerbomb and it increaded power just like it said it would. had to re jet the carb so the bike would run write. great sound but not rediculously loud
- Motorsports:
- Casual Rider, Competitive Rider
Pros
- Lightweight
- Tough
Cons
Best Uses
- Off-Road
- Racing
- Street Riding
- Upgrade
Comments about FMF - Factory 4.1 (Slip-On):
adds a nice fmf rumble to my bike. Exhaust can be run loud without any insert or quiet with a quick fit of the quiet insert which is supplied with the pipe.
- Motorsports:
- Casual Rider, Competitive Rider
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