Stock muffler with Megabomb header?

Hey,

I tried out the FMF setup and its just to loud for me. I know, I know more power old man but I like to be a bit of a hooligan in town and its turning heads. I was thinking about keeping the FI controller and megabomb header as I have already removed AIS, air flapper and EXUP systems.

Any words of wisdom on this? Am i keeping any HP gains with the header but not the muffler? I'm pretty sure at this point with all I have stripped off I need the FI controller no matter what I do (short of putting it all back).

thanks

doc_simple

I see no reason to need, nor do I see any benefit in having a non-stock header if you have the stock exhaust can on the bike.

You may benefit from keeping the EFI unit in order to perhaps eliminate a touchy throttle spot in low range, but generally speaking I don't see much reason for even that other than you already have it attached.

You may want the AIS system back on bike as it's there to provide some assistance on protecting the stock exhaust from backfires and pops which may damage the catalytic converter.

I modded the spark arrester in my fmf Q4 to make it quieter.
I just welded a washer over the end of the spark arrester, it was easy to do and made it a bunch quieter.
I posted pics of it in some tread, it was called quieter q4 or something like that.

There was also guys running the fmf header and stock mufler on this site years ago, it adds a little power even with the stock muffler. I think you need to remove the gasket from the inside of the mufflers pipe to get it to fit.

Motokid - I have seen threads where people did the AIS, EXUP and flapper but used the EFI controller to get rid of the pops, ect. Not sure I could even get it all back on at this point. I don't think I have seen an instance with that and the header only changed though.

Biglake - I found that picture. I just want o be clear , that piece you are holding in the picture is the SA which is removed by undoing one bolt on the end? I'll have to take it somewhere to get that welded as I'm not that handy yet but I'm willing to give it a shot.

here is that thread:

https://wr250rforum.forumotion.com/t6136p20-quieter-q4-solution?highlight=quieter+q4

thanks for the replies and info

and isn't the guy who cuts and bends the pipe on this page:

https://wr250rforum.forumotion.com/t6136-quieter-q4-solution?highlight=quieter+q4

basically doing the same thing as Biglake is adding the washer? He is restricting direct pass through of air but the cuts will allow more air through the sides similar to what your design does. I could see this causing part failure sooner than the washer but as they only cost about $30 I could ride this fro a couple years I think.

I like the weld idea better but I can cut metal and do not have a welder in the garage. Thinking this might be a quick and free mod...

The piece in my hand in the picture is the spark arreserter, it does come out with just one allen head bolt.

Cutting and bending like the guy in the other link did woiuld work fine too.
I welded a washer onto it as I can weld a bit but not well so it was easy for me to do and like I posted in that tread I copied the hindle quiet core I had in a hindle pipe.
Either way is reversable, its easy to cut the washer off or bend the cut peice back to straight.