Stock Muffler/Exhaust Mod

I've been hunting around this site, but can't find a decent explanation of how to modify a OE muffler (Exhaust to us Limeys!) to make it louder. I can hardly hear my bike as I ride it.

Seems there's plenty of people who have just lopped their exhaust off or stuck some straight pipes on, but I have to get the bike through the Swiss Expertise (Roadworthyness test) so I can't do anything dramatic and I wanted something cheap or free... And anyhow, if it's too loud, I'll get avalanched on..

So, back to the mod.. The only thing I could find to read was to drill out the rivets with 3/8" drill bit.. Won't that make the back plate fall off?? Is that all there is to it? In the later Yam exhaust mods, there's a baffle inside that can be removed, I'm not sure how because my XJR has after market cans, but it's apparently effective.

 

Well swiss, i have an 83 maxim 750 with stock dual exhaust, and all i did was drill into the baffle plates to make mine louder. Started small with 4 holes on each plate, and when that wasn't loud enough i dreilled 4 more on each plate. When that wasn't loud enough i made the holes bigger until i was happy with the sound and volume.

 

i'd loose the muffler and stick a straight pipe on it. not more than 20cm long. at least thats what i intend to do.


when i get to it



*** sorry i didnt notice you want to mod the oe muffler...

i prefer exhaust too

 

+1 on the drilling holes in the baffle plate. Its what I did too before I got my 4-1. I think ended up drilling 5 holes to 3/8", but start small and work your way up in sizes until you get the sound your looking for. Its easier to drill larger holes than fill a hole that's too large

 

Oh yea and check out your spark plugs before and after so you know how much, if any, you will need to adjust for a leaner running engine. :wink:

 

Thanks everyone.. I'll get the drill out when I've got the bike on the road.. Not so keen on the 4:1.. I like the look of two pipes.. Kinda makes the bike symetrical.. I'm wierd like that LoL.. If I can't get what I want from the stock exhaust, I might look after market, but really I'm looking for cheap mods cos this is my "other" bike.. The one that was supposed to keep all the dents and knocks in and ride to work every day, instead of taking it to bits and doing a load of mods on and riding the nice bike into town to get dents and scratches.. Ha ha....

 

I put 1 1/2id-1 3/4od adapters on my bike with 1 3/4 x 12" of pipe, (actually I used turndowns and swapped ends to clear the center stand) then used 1 7/8- 1 1/2" adapters for end caps and the low rpm power and torque improved drasticly, from 3000 rpms up to about 7 grand (but sounded like a smaller 2 stroke) so I cut the tips off at the sholders and rotary filed them to 1 5/8" id and re jetted the carbs & the power band moved to from 5 grand to 9 it ran smoother (than just open pipes) but it was just too loud for my taste. Roll on full throttle from just above idle in 1st would spin the semi slick 120x18 Kenda challenger (stock size for a 750 seca) from a light.

 

Wayyyyy ahead of me there padre.... Perhaps next year LoL...