Don't install your new FMF pipe in the dark with only a flickering headlamp in a light rain with a headcold.......cuzz it's not a good time just put the powercore 4 on and man would I like to strangle the guy who put those header bolts where they are... after scraping all the skin off my fingers I did get them loosened enough and the pipe went on easy as pie, did not use the sealent yet but I am going to once I get some.first impressions of the pipe are "wow thats light!" and "man does that ever look good" then I started her up(not a good idea at 11:30 at night) and man is that thing loud compared to stock,nothing terrible but it has a really good deep sound to it,I have not gone for a ride yet but It feels like the throttle response is faster,offcourse that may be an illusion due to the sound but so far I really really like it, sure SOUNDS more powerfull
ride report to follow.
Thanks,
Hunter.

 

Hi I'm looking at to get one of these exhausts for my bike, where did you get yours from. Have you got a pic you can share with us? Thanks

 

Silencer for that pipe with out losing HP

https://www.denniskirk.com/435531.sk...FfFcMgodoz8AGw

 

I bought the Pipe here FMF Racing PowerCore 4 Spark Arrestor Slip-On Exhaust - Canada's Motorcycle but it is available at most places that sell dirtbike parts,can't put a picture up right now as I don't really want to fiddle with it but just type in "KLX250 FMF powercore 4" on youtube and there are plenty of vids.
*RIDE REPORT* still have not taken her out in the roads yet but I did go for a rip in the back field and it is alot more powerfull and just seems like it revs better,it no longer gives that impression that it is going to blow up when you crank it HOWEVER that nasty flat spot off idle seems much worse,what would cause that? I hope it goes away when I rejet
Thanks,
Hunter.

 

Sounds like you have a lean bog off idle. The increased airflow just made it worse. Might want to consider at least playing with the mixture screw to richen it a bit off idle. If that's not enough - maybe one size larger on the pilot jet, but most members here find the stock idle jet works well.

My 300R came with a powercore 4 and I didn't like it that loud. I added the insert shown above and it did tone it down a bit but not enough for my old ears. I eventually went back to the stock muffler (destricted) with a Stroker headpipe. It has as much oomph as the powercore but is tolerably loud now.

Anyone want to trade their low-key FMF Q4 for my louder Powercore 4? I'd toss in some cash to make it happen.

 

out of stock

 

On my 09 I did the mods 1 at a time so I could see which did what. The silp-on was the single best mod, period. It flat made a huge difference. Later I pulled the snorkle and jetted it with a performance ac, added a powerbomb last and with each mod it got alittle better. Get a jet kit and ac as you won't be sorry, and the screw could help with the flat spot back it out to 2 or 2 and a half and see.

 

I will note that the bog off idle goes away once the bike has been warmed up,still safe to ride running so lean?

 

it is a FmF part so you maybe able to order it some where else

 

I'd think you can ride it as if it lean it you'll probably notice. If your really worried don't ride it all that long but FMF even says you should be fine, that said you need a filter and a jet kit to get the most out of the 250.