Jump to content
Sign in to follow this  

FMF product information

Recommended Posts

Mike from FMF sent me this info on some of the new FMF products including the new Power Core IV-2 SA (Spart Arrester). I'm not sure who performed the tests but it is certainly interesting. The test was done on a YZ426.


Power Core IV-2 Spart Arrestor Part # Y-421 $289.99

Exhaust note is quieter than stock. You can tell immediately even though it's fully forestry legal that there is a huge and very rideable performance for the YZ 426. Performance is focused towards improved bottom to mid-range power designed for the off-roader. The majority of the power increase was distributed through the lower to mid sections of the power band, while still improving the 426's over rev. This new unit has the Power Core IV-2 S/A 3/4 length wing installed and power does not suffer though the DB level was corralled.

Power Core IV-2 Part # Y-420 $269.99

Exhaust note is 2-3 dbs quieter than stock. You can tell immediately that there is a huge and very rideable performance for the YZ 426. The majority of the power increase was designed for the motocrosser, improving bottom end over stock, while focusing most of the power in the mid to top-end regions. This new unit is a straight through design, that is constructed out of FMF's exclusive square core.

Power Bomb Header Part # Y-421H $189.99

The stainless steel Power Bomb unit was originally designed to offset noise penalties associated with a higher flow rear exhaust unit. FMF's Power Bomb knocks 3-5 DB off the meter and makes for a very realistic power gain-mainly bottom to mid range. With the trademarked Power Bomb, FMF realized that the evacuation of sonics gained considerably with the expansion and cooling of exhaust gases into the bomb, then have it recharge to provide a gain in flow characteristics. No loss here, and all gain!

FMF AOF Ignition Part #43-84-02 $399.95

The new AOF Ignition keys in on the TPS (throttle position sensor) and uses the supplied information to select the necessary of three curves available during acceleration. During lower RPM, the AOF ignition will use a curve to improve throttle response and torque. When the throttle is opened up, the AOF will supply a curve to improve mid-range which increase acceleration, and improves top-end in the WOT position. Using the handle bar mounted switch, the rider can select between a top-end "Boost" mode or a torque supplying "Torque" mode. With 2 modes, and three throttle position sensitive curves per each mode, the AOF Ignition will increase power across no matter what the situation.


FMF Power Core IV2 spark arrestor: 5.06 lbs.

Stock muffler: 5.76 lbs

FMF Racing

18033 South Santa Fe Ave

Rancho Dominguez, Ca 90221


Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

  • Similar Content

    • By BDTRENT
      Selling an FMF Power Core 4 exhaust system off my 450FX. Exhaust has 80 hours and is 100% functional. This will also fit the 14-15 YZ450F and 16-18 Wr450F. If needed I can also include new muffler packing although it does not need it. 
    • By Woody Oakson
      I have a 2008 YZ450F with a stock header pipe and Pro Circuit T-4 Slip-On Exhaust. I'm 99% sure the slip on is shot because its loud as hell and when I take it off and shake it it rattles. I would repack it but the screws are all stripped ect.
      Anyways I've gone over the carb multiple times and I've got it running pretty well. The only issue I have with the bike is that it sputters and pops around 1/2 throttle when I hold it there. When I give it full throttle from any RPM it runs great or when I give it about 3/4 throttle it spins up like a top to redline.
      Initially the popping and sputtering was way worse I made the situation better by moving the pilot jet up in a few sizes from a 45 (stock) to a 62. The issue has gotten way better since then but I'm not super sure what to do from here. Should I keep moving my pilot jet up in size because that's a pretty large jump right? I tried changing my needle clip position but that didn't help much if anything it just made starting it worse and little to no impact on the ride.
      Any input on this would be helpful. I don't want to buy other slip on. Also as for the rest of the carb I'm very sure everything else in it is what it needs to be at. I've replaced all the gaskets and O-rings cleaned all the jets, valve holes ect. fixed the accelerator pump timing. I just thinks its strange that my pilot jet size is going so far from the stock 45, but all symptoms point to the bike running lean.
    • By Haydenbaha
      Hi I was wondering if y’all have been using a 450 on your YZ250F?
    • By RockerYZWR
      Excel Takasago 17x3 front and 17x5 rear supermoto wheels with Metzler M3 tires in very lightly used condition. Less than 200 miles total on the setup. Warp 9 spokes. Rear has a Talon hub with 45T Sunstar steel sprocket and OEM rear disc, and front has a polished OEM Yamaha WR450F hub (for the stock speedometer), with a Motomaster 320mm disc. Included is a DID gold o-ring chain, 14T front sprocket, and front brake caliper adapter for a truly turn key setup. Everything is in excellent condition, not a single scratch on these wheels. Came off my '11 WR450F, but will fit many different Yamahas with 20mm front and 22mm rear axles. Asking $1400 plus shipping.
      **Will be driving up near Atlanta, then to northern Louisiana, OKC, and down through Dallas and Houston, TX soon -- can meet or deliver if in the area (Aug 31-Sep 9)**
    • By YZ426fNC
      Hi I’m new on the forum and I was wondering if a 2001 Yamaha YZ426f clutch is interchangeable with a 2002 Yamaha YZ426f clutch thanks , Coleman