FMF Q4 exhaust, tight to airbox?
 

So I got a great deal on a used Q4, thanks cpr1, and put it on last night. Stock header.

I didn't get any instructions of course and since the site's search engine can't handle short words like fmf or q4, I'd like to ask you folks.

I plan to reassemble with copper RTV for the seal at the header to muffler joint. Good idea?

I had to bend the metal wire foot guard and that seemed to work fine.

My big question is the airbox clearance. The pipe is really close but not hitting, the airbox. Is there a way to adjust this? Has anybody melted their airbox? The pipe here will be getting hot and I'm at just over 1mm of clearance. Less than an 8th but more than a 16th. I loosened everything and tried to reinstall farther away but it laughed at me.

Sound is great, much louder and my jetting is now lean.

Yes, I melted an airbox right there. One of the airbox bolts was loose and allowed it to sag just enough to touch and burn a nice big gaping hole. Luckily it was on the dirty side of the filter so no worries.

I got a new box, and wrapped that section of pipe with exhaust wrap. It's been fine since then. I know some people don't like the exhaust wrap for fear of pipe damage, but it works for me. If it messes up the pipe over the years oh well, they don't last forever.

Or put some heat tile type stuff over your box.

Heat tile ? You know what I mean.

My full FMF header/slip-on...did melt my box right on the corner,not bad but some,didn't go all the way inside,so It is what it is..love the pipe really dissapointed with FMF and the fit...Melted my blinker too...bad fit design really surprised in the Company cause FMF is a top Co. I did let them know on my regestration/warrenty card....bad fit folks

I don't have the Q4 but I've got a powercore 4 and ran it with the stock head pipe and then a powerbomb and have no issues with anything melting. I wonder if it can be twisted out some and you do have to really bend that brace by the back foot peg.

Yeah.....I can't say that I had any clearance issues with the Q4 when it was on my bike. I have the Power Core 4 on it now and no issues.


Time to rejet that carb Joe! ;)

FMF Q4 with a stock header on a 2007 here. Looks like about 1/2" clearance from the pipe to the airbox. I don't have any melting after hundreds of miles.

Is your slip on for an 09 by chance? They have different part numbers from 07 to 09.

My FMF Q4 with megabomb was melting the airbox from the get go!! Had to do a little light fabrication to drop the silencer down about one centimeter & this has stopped the meltdown (about a 30 minute job with the right tools at hand). But i'm pissed that I even had to do this with a big name company like FMF!!

But great sound & noticeable power increase.....so all good :-)