hmf competition series exhaust re-jetting

I just bought a HMF competition series exhaust for my 2011 wr250r and am concerned about the re-jetting or re-mapping part of this modification as I am not mechanically oriented. Is this something I have to do, and if not will I do any damage to my machine. Any help will be greatly appreciated. Tks, Zac

If you have a programmer it'll be a good idea to re-map it. If you don't have a programmer, it'd be a good idea to get one.

Jets are for carburetor. This bike uses EFI. Fuel programmers are needed on EFI bikes to do the same job jets do, add more fuel to compensate for the addition of air flow. A programmer is recommended when you've done performance mods, like an exhaust.

zdenton wrote:

I just bought a HMF competition series exhaust for my 2011 wr250r and am concerned about the re-jetting or re-mapping part of this modification as I am not mechanically oriented. Is this something I have to do, and if not will I do any damage to my machine. Any help will be greatly appreciated. Tks, Zac

I also have the HMF Competition exhaust on my '08 WRX and they send you 3 exhaust tips. If you run the largest diameter tip, you need to remap the EFI. If you run the medium you will probably be ok with out remapping. If you run the smallest tip you also need to remap. I got this info from HMF themselves. I am running the largest tip with a Dynojet PCIII Power Commander (fuel programmer). I believe I am running the Graves map and I tried putting the medium tip in using the same map and it was way too rich. If you do not buy a fuel programmer, then I would not use the largest exhaust tip, I would stick with the medium tip for best performance with the stock settings.

The smallest tip is smaller than stock? I find it hard to believe it restricts flow more than the stock setup. For most people you couldn't tune a more restrictive setup anyway - the FMF type programmers can only add fuel, not take it away. How small is the outlet on the smallest? Is it really quiet?

Hey, we need some audio of this HMF. I am looking into a slip on and ran across HMF online.

My problem is there is only one video I found online and it is only revving and some idle. It does not state what insert it has etc and there is no drive by etc.

I wish I could make up mind between the following:

+GYTR
+FMF Power Core 4
+FMF Q4
+HMF Competition (3 inserts)

I had never heard of HMF before and the other issue is:

-No AZ dealers
-No tried and true setups for the FMF programmer

Any audio and video would be awesome.

JustWannaRide wrote:

Hey, we need some audio of this HMF. I am looking into a slip on and ran across HMF online.

My problem is there is only one video I found online and it is only revving and some idle. It does not state what insert it has etc and there is no drive by etc.

I wish I could make up mind between the following:

+GYTR
+FMF Power Core 4
+FMF Q4
+HMF Competition (3 inserts)

I had never heard of HMF before and the other issue is:

-No AZ dealers
-No tried and true setups for the FMF programmer

Any audio and video would be awesome.

Having run multi exhaust systems on my WR-R. I prefer the FMF Q4.