How much can I drill out the stock exhaust before re-jetting

Im looking to have a little more aggressive sounding exhaust on my 83 750 max, I was thinking about drilling some 3/8 inch holes in the back of the baffles. Has anyone else done that?


Could I do 8 per side and still avoid having to re-jet or adjust the valves??

 

You mean the very back of the stock muffler cans, around the outlet?

It won't make it any louder. That chamber is just dead air back there, the exhaust "exit" pipe is supported by a baffle plate a few inches further in. All you'll do is turn valuable stock mufflers into trash.

 

Re: How much can I drill out the stock exhaust before re-jet

See this

 

Re: How much can I drill out the stock exhaust before re-jet

Your post (and others) got me thinking.. so I tried it. I drilled four holes around the center hole in the end of the mufflers (started very small and stepped up to a 5/16" bit). It's definitely louder and I can't tell any difference at all in performance. I'm considering doubling the number of holes and/or making them a little bigger but don't want to over do it & expedite the exhaust mods & re-jetting I have in mind for next year. I think it definitely sounds cooler now but it is a little "farty" :lol:

I'll try to get a pic and maybe a video up later on.

 

Re: How much can I drill out the stock exhaust before re-jet

http://www.youtube.com/watch?v=smSUEPZw ... e=youtu.be

Pardon the crappy quality - didn't check the camera setting until after I had it uploaded on my PC. This is more for audio anyway, right?

 

I had already done 4 holes the day I posted this video, I was going to do 8 but thought I would ask here first.

Its definitely a little bit louder with the 4 holes........