Drilling the Exhaust

BoomerSooner's picture

I’ve been a silent naysayer about drilling out the exhaust. It’s just one of those things that’s a personal choice, and it was something I didn’t want to do as I normally don’t like altering the stock parts, but events of late have changed my mind. There have been a couple of events recently on the road where I thought louder pipes would have helped, plus with the way things are going right now, I just don’t think I’m going to have the funds to purchase the pipes I want for quite a while.

There are plenty of posts on various forums describing and showing the muffler being drilled, and from what I’ve seen there seems to be 3 popular methods to drilling, so I’m going where pretty much everyone else has gone before.

Will this mod void the warranty on your bike? No
Will it void the warranty on the muffler? Absolutely!

You've been warned.

So let’s get started!

What you’ll need:
12 inch extension
1 1/2 inch hole saw,
1 1/4 inch hole saw,
3/8 inch drill bit

Decide what hole(s) you want to drill. Many have opted for a single large hole using either the 1 1/2 or 1 1/4 inch hole saw, while others have drilled 6 holes using the 3/8 inch bit. The thinking being that the multiple holes diffuse the exhaust which creates a more mellow and less “blatty” sound. I have no point of reference among them, so I can’t help you decide which way to go. The 1 1/2 inch is the largest you can drill out and seems to be the most popular, so this is what I did.

We’re going to be attacking the muffler from the rear:

About 10 inches down the pipe is the baffle plug we are going to be drilling out. I’ve tapped it with the drill bit, so that’s the shiny spot in the middle:

Put together the drill, extension and bit:

Run the bit down the pipe:

Carefully start drilling:
NOTE: You know how to drill. Stop/start the drill a few times so the pilot bit can get a bite, then take ‘er easy.

Once you drilled through, start up the bike to blow out the plug.
WARNING! Don’t have anything or anyone directly behind the bike, as this piece is going to come flying out. It’s not a nuclear missile, but no sense being careless.

Yah, yah, I did start drilling with a bit and changed my mind.

Here’s the result of your labor. You can see it’s now a straight shot through the baffle:

And that’s all there is to it!


How does it sound? Not too bad! Seems to have a pretty throaty sound to me without being overly loud.

First ride impressions:
This mod really didn't add a lot to the volume, which is fine with me. There is a bit more of a rumble to it on acceleration and when you give it an extra twist, but pretty mellow otherwise. I like it!

Now, what really surprised me is how much the engine has smoothed out since doing this mod. Even with a fuel manager and ThunderAir kit I still had some low end chugging, but removing the baffle plug has almost completely eliminated that, she feels smoother over the whole power band and it seems she has more power overall. I can't believe how restricted the stock exhaust was. This improvement alone was worth the mod and now I wish I had done it a long time ago!

There are tons of examples and discussions about doing this mod , so definitely don’t just take my word for it. Do a little research before deciding what you want to do.

If you want a good description of what is going on inside your muffler, Kaelar has provided an excellent writeup:

Oh, and for pity’s sake, use a good drill bit! Mine was cheap and caused this to be a far larger effort than it should have been!

Boomer Sooner
Potestatem obscuri lateris nescis

Mods & Tickets from the local constabulary!!

In Ottawa it seems riders are getting tickets for modifying the pipes when the noise is too loud. A friend just got a 130 $$ ticket. I completed the drilling a couple years ago and have not yet (knock on wood) received a fine. I am now thinking of putting on some unmodified aftermarket mufflers/pipes that are louder but not too loud.

Check your local laws and see what is ok and what is not before you mod – one never knows when the red lights will flash!

Ride safe.

Piece blown out..

Watch this if you want to see the piece blown out !!
At 2:38 sec's.

Thanks Nightflight...


You're welcome Kokkie... I

You're welcome Kokkie... I am trying to get you that extension bit/part now so we can work on Kwebbels 1300 Trike on our "Knutseldag".....

Rob - in the Dutch mountains....

Great instructions..easy, cheap mod!

Do what you like........and like what you do!
Thanks for a fine description and details on how to accomplish the baffle removal. I'm not one do typically do things like this, as stock is often OK. But I wanted a bit more sound, mostly for cagers to hear me better. I took the bike in this week for it's 600 mile service. I asked the tech about this mod, and if it would effect warranty. He suggested I not do it, but use a "slip on" exhaust instead. Some explanation about back pressure, fuel mix, EFI, ect., which I don't really understand. As far as warranty, they said as long as the problem was not a result of drilling out the baffle, warranty is OK. Of course, that leaves allot of "gray area".
However, when I talked to the parts department about a slip on, they checked and said that the Tourer model did not have a slip on option due to the bags. At least not in the catalogs they had. Only one they had available was a $600+ Cobra, that was rather ugly. So, when I told the tech, he said the drill out was my best option. So, I got home and did it in 5 minutes.
It does improve the sound, a bit more throaty, and a little rumble. But not obnoxious like many bikes I hear. I don't really notice much difference in power, but then again, I only rode it 600 miles, and carefully during the break in. So I'll never know about that benefit, but I do like the sound better than stock.

Did the far back holes, should I still drill the baffle?

I drilled seven 3/8ths holes at the very end of the muffler (thru both layers) on my '09 Tourer with 20k on the clock, then drove it 400+ miles on the highway to get back home. My MPG definitely improved, and the sound is a bit louder and definitely "deeper", and it did help smooth it out.

My question is: Would I see any additional changes in sound and volume if I added drilling the baffle that's 12" in?

Finnaly did it

So I took the plunge and drilled my exhaust today with the 1 1/2" hole saw. After driving it around for a couple of hours, i gotta say I love it. Nice low speed rumble. Almost no chugging at low speeds. not much louder at highway speeds. And I belive I have and improved feel for the shift speeds due to being able hear the engine a bit better.

Two thumbs up for this one. Highly recommended.

My next mod will be one of the K&N air filter mods.

Drilling More Holes

I drilled the 1 1/2\" hole about a year ago and thought it was a good move. Today I decided to drill five (not sure why I picked five) 3/8\" holes at outside of exhaust. It is a little louder and from my short ride around the neighborhood the popping I had on deceleration seems to be gone.


A Skeptic no more!!!

I drilled today and all I can say is WOW! A perfect nice rumble... now to add the Cobra Fi200R ... I have my helper coming tomorrow and we put it on... will be like having a new bike!

Yamaha Engine Guards
Knight Riderz 21 LED Light Bar w/Brake Alert
Dual WOLO 306-2T 130DB+ Chrome Horns
BARON: Big Air Kit, Mini-Bullet Tach, Fork Bullets/Axle Nut Covers
Kury Super Lizard Lights
2 tone seat

Cheap and Easy

Thanks for all of the comments on the mod of the exhaust. Not to many things you can do with the bike for $20 bucks in tools that make such a nice change. Hardest part was finding the extention for the 1 1/2" bit. Lowes was out so I had to hit 2 other store before finding one at Home Depot.


Drilled out my exhaust today on my '07. It took me longer to get the tools need at Home Depot (and for you military id card holders don't forget to show it at Home Depot for you discount!), set up and clean up. Drilling out the baffle was done within minutes. After starting the bike up it noticed a more deeper bass sound. Loving it! Thanks for the great how to! Those of you in the Rochester, NY area, I got the tools, you can borrow it anytime!

If you have just road

You should be impressed with the power change.

Another convert

I just drilled my exhaust today. Like some others, I had some concerns that it might be too loud, or cause other problems, but all the reassurances in the comments here did the trick. It took seconds to drill out, using a 1 1/2" hole saw. Given the cautions about the piece flying out, I leaned a board against the exhaust and restarted the bike, and that safely blew out the piece. I tried recording videos of the before and after, using my Contour, but even with tape over the mic it still has far too much wind noise to be of much use for sound. The sound *is* lower, and a bit louder, but nothing like the Motor Company's noise. I didn't notice any more pops on decel, but the ones I get are now also louder and lower in tone. As others have said, it only makes much difference when you get on the throttle (or all the way off. Also, I didn't notice any change in available power, except the reduction of very-low-rpm chugging, which I generally avoided through proper shifting. Some here have claimed increase, while others have complained of decrease. I'd be interested to read of any dyno tests, or other objective comparisons. My only expense for this was the extension, so it was a cheap, easy mod. Now I just need to see what my wife thinks of it.

Drilling The Exhaust

Considering drilling the exhaust on my 2007 V Star 1300 Tourer. Said something at my local Yamaha Dealer and they said you can't just drill the exhaust. They said I would have to re-tune the EFI anytime you modify the exhaust or intake. Did you or anyone you have heard of have to re-tune their EFI after this mod?

Drill Drill Drill

You will have a new bike when you drill. You will be VERY happy.


No - drill it and then go

No - drill it and then go ride it!....paul

The difference between adversity and adventure is attitude.

Go ahead and drill!

Installed the Barons BAK few weeks ago. Made a huge difference! More power, louder exhaust tone, and less surging. The sound of the air sucking in is amazing compared to no sound with stock. When I pulled of the stock air cover I found a large amount of lint virtually clogging my stock filter. Bought this 09 leftover 2 months ago. Guess a mouse at the dealership was living in my stock airbox! After reading the posts about drilling the exhaust a few hundred times, decided to go for it. Well worth it. More free flow, ever better exhaust tone, less surge. 1 1/2 hole saw did the trick in about 60 seconds. Loving this bike. Can't get enough of it. Bucks lowers next. Wife wants to know when the add ons will be done. I guess when I run out of money!
This site has helped me so much with ideas and feedback! Thanks to everyone!

First Time Modder...

I got my 2007 five months ago and have really enjoyed. After reading the how-to on drilling few months back, I have been keeping up with posts and getting nerve up as well. I would like it a little louder around the other bikes in the Star group but I don't care for the over-the-top thunderous exhaust on Harley's and other. I knew there would be no going back once done so I keep watching others post's. Finally I bought parts I needed and did it . It actually sounds good. I can only tell the difference at stopped and slower speeds. Highway speeds sound no different as before except more small backfiring when letting off the gas. I can't tell any less lugging that others can. Overall I am pleased I did it and that it was so easy since I am not very experienced with bike repairs. Wished I would have thought to do a sound byte of before and after for others sitting on the fence about drilling their exhaust but didn't think about it at the time. No regrets so far.

New to the Star....Is there

New to the Star....Is there a prescribed amount of time one should wait before drilling the exhaust on a new bike or is it ok to drill as soon as you get the bike home?


I did mine after the first service at 600 miles. I was sorry I did. I did the 1.5 inch and it really didnt make that much of a difference in my oppinion accept for removing the warranty on the muffler, exhaust. I didnt feel it made enough of a difference, went aftermarket.

TC Bob

Whatever your comfortable with.

I think a lot of people wait until after the first service just to make sure there are no issues with the new bike. I don't see anything that drilling the exhaust could affect but it could give Yamaha a reason to deny something under warranty.
I procrastinated until 1400 mi and like others have said here, I should have done it earlier. I have over 3200 mi on the bike now and am happy with the results.

2009 V Star 1300 Tourer
The Blue and Silver One

Thank you for the How-To

Yes, this one is a no-brainer. Definately louder upon acceleration and made the ride more enjoyable. I almost got sideswiped in downtown traffic at slow speeds last weekend so I'll take any increased volume. Thanks Boomer Sooner and everyones reassurances. It only gets better even if its just a little.

As others have said, it will

As others have said, it will sound even better and a little louder with a lower tone after 300 to 400 miles. Mine is just what I was wanting now, loud enough to hear and increase power but without being too loud.

2009 V Star 1300 Tourer
The Blue and Silver One


Drill you will not be disappointed 100 % improvement.
Like a lot others I just was not sure. I did & I was very surprised of the power and low speed chugging gone.
Drill Ted Drill ! Ride safe Raymond

I Drilled.

I put a K&N air filter on a couple of weeks ago and didn't do anything to the airbox. The results were very positive, eliminating a lot of the lurching, increased power, and smoothed out the engine.

Last night I got out the extention I bought about a month ago and drilled a 1 1/8" inch hole in the muffler baffle.
I have almost 1500 miles on the bike and since I already had the hole saw I didn't see the need to spend the money for one a little bigger, just bought the $10 extention. It only took about 5 minutes to drill after I gathered up the tools.

As Boomer said it didn't sound to much louder until I put a few miles on it. I rode about 60 miles both in town and on the turnpike at 70 mph, with the majority on the turnpike. The improvement is very noticable. The bike seems to run much easier and smoother and the lurching is virtually gone at low speed. What I mean by easier is that it doesn't feel like it's having to work hard running down the road or pulling a hill. I can hear the exhaust going down the road now where I couldn't before, not loud, just a nice low hum. At lower speeds it is louder but not too loud, just a nice low rumble. You can definately hear it when you pick up the throttle now. I rode next to my friends Harley Ultra with Rinehart pipes and about four Harley's with long shot pipes on the street. If you want something that loud then you will be disappointed. If you are like me and just want to be able to hear your exhaust and gain some power without being annoyingly loud on the road then this is the modification for you.

As everyone has said, I am glad I drilled.

2009 V Star 1300 Tourer
The Blue and Silver One

Two Questions.

I'm one of those guy's who doesn't like to change stock too much but have a couple of questions.
Has anyone drilled one smaller hole than the 1 1\4" or 1 1/2"? If so did it work as well as the larger holes?
How does drilling affect the fuel mileage?

I bought a holdover 2009 and have a little over 750 miles on it. Probably won't drill for awhile but was curious if the mod changed the fuel mileage. I wouldn't mind it being a little louder as long as it is still a pretty deep sound.
Would also like to get rid of the low speed jerking and lurching.

2009 V Star 1300 Tourer
The Blue and Silver One

John, Do the Jack's O2 Mod.


Do the Jack's O2 Mod. You won't be disappointed. Takes care of the surging at low speeds and improves driveability greatly.


Jack's O2 Mod

Was just looking at it again today, thinking about just getting the resistor and doing it myself. It is way better since drilling the exhaust and installing the K&N air filter, it's nearly non-existant now, just once in a while if I lug it to much at take off.

2009 V Star 1300 Tourer
The Blue and Silver One


You will not be sorry . You will have a new bike with more power.
So many of us waited & waited to long to do it.

You will be happy,Raymond

Drill Brother Drill

Hello John, Drill when you feel comfortable with warranty & dealer.1 1/2 hole saw will get rid of low speed lurching & add to performance. Gas mileage will not change . You will see a big difference in performance .
With all that is in the how to section you will I am sure be happy . It took me a while to drill and I should have done it sooner then later I
was very surprised by the new bike feel and more power.
Wish you the best .Good people here on site. Raymond

Thanks Guy's.

Thanks for the info, just hadn't seen much about the drilling effect on fuel mileage. I also don't want it to be real loud but would like a little more and the increased performance. It's easy to drill, putting it back is a lot harder.

Taking the bike in for it's first service tomorrow.

Thanks, this is a great site.

2009 V Star 1300 Tourer
The Blue and Silver One

I Did mine at 900 miles

It smoothed out the lugging noticably. The sound was some what louder but, at idle it really wasnt noticable you have to be getting into it to make a rumble, and still its a pretty mild rumble. I used a real good 1.5 inch saw blade, and bought the extension. the total cost was just at 20.00 from menards. Took me less than a minute to run it thru. My thoughts after doing it was if you really dont have the money for a full exhaust its a cheap way out for minimal expense but check out the price of the factory stock exhaust that you just took out of warranty for the gains made, I am not sure in my oppinion that its worth the trade off.

TC Bob

jeffb John, because I had

jeffb John, because I had trouble finding a hole saw bit that would cut the metal, I ended up drilling a bunch of holes about 7/16" dia. I listened to the change after each hole, liked the difference and continued until the equivilent of 1 1/2" dia was drilled out. I dont really like loud but the low rumble sounds good. Even so I find the incresase volume can get old at the end of a long ride or when doing a lot of back road hill climbing. The mod definitely adds performance especially noticable cruising at low rpms. (Do the Jacks 02 mod too for the lurching)

Excellent mod...awesome outcome!!

I've been reading and researching the exhaust mod, and after reading everyone's positive comments...I finally drilled mine today. Spent $20 for the extension and hole saw and a less than 30 seconds after I started, I was done. I was so impressed with the sound, the low rumble, it really made a difference. I did want a little more sound, but not ready to throw upwards of $600 plus for a new system and possibly a fuel management device. I just couldn't wipe the smile of my face. Keep riding ya'll!!

Does size matter?

Why 1 1/4 or 1 1/2? Is it personal preference? Just wondering. Why not drill it all out to have a straight shot? Has this been asked already and I missed it?

personal preference

Some have stated that the sound of 1 1/4 was good enough for them. 1 1/2 is as big as you can go. It's really not that loud, just a nice little rumble. More quiet than a slip-on would be, I believe.

Boomer Sooner
When I die, I want to go like my Grandfather - peacefully, in my sleep, and not screaming like the passengers in his car.

USED 1 1/4"

Well I finally got it done last nite. Used a 1 1/4" and man did it make a difference. My mom-in-law, sitting inside the house heard n felt it. I used to open the garage n rev the eng a few times to let her know I was home and she never heard me. haha Now she knows when I start it up. haha again!!
It is awesome!! Took it for a ride and man it feels good to know I will be noticed a little more when i'm on the road. My wife loves the "VROOM" as she puts it. Didnt please the neighbors though at 9 last nite, but its the only time I had and wasnt gonna wait til Saturday morning...HELLO!! Thanks for all the help n info boyz! Have a good one.

-Be loud, be noticed...respectively-

Exhaust'ing the law

Hey, I was running this by a fellow rider friend of mine who was in law enforcement. He said there is a chance, especially being in So.Cal., that this "mod" can cost "you" if an officer sees the baffle drilled out...for whatever reason "you" may have been pulled over. Anyone come across this issue? Just a thought as I am not 100% on exhaust laws n regs. Thanks guys!


It would be interesting to find an officer who knows the construction of every OEM muffler out there. The plug is drilled out waaay up the pipe and he would not only have to know what it looked like before but he would have to get down on his hands and knees with a flashlight and identify it now. With it being nice and carbon covered now, the pipe passes straight through and looks OEM.

If it passes emissions and noise levels, why would they care?

Boomer Sooner
When I die, I want to go like my Grandfather - peacefully, in my sleep, and not screaming like the passengers in his car.

Less HP

I have had this mod now for a week and have done about 200 miles. The bike is much louder and when you come onto it people notice. The one complaint I have is that it really does feel like it has less snap and horse power. I mean if feels smother like others have mentioned but I can honestly say I don't like it. Glad I did the mod but not sure if it will stay long term because of the feeling of the HP loss.

Also I do get alot of sputtering when down shifting.

Less HP about a year later

What are your thoughts about this mod now that we are about a year later?

easy mod that sounds great

I bit the bullet and tried it. The sound is much nicer now and when you crank the throttle it is noticeable. Drilling took about 10 seconds. Go slow and it will come right out. I got lukcy and my piece stuck to the drill bit and pulled right out.

Easy Mod / Cheap Mod

I have to say that this was one of the easiest mods I have ever done. The sound IMO is very nice and is drastically better than the stock sound. I do get a little backfiring and sputters but I actually like that (if you can believe it). I used a BiMetal rigid drill bit (1-1/2 hole) and the jobe was done in 10 seconds.

Finally did it too

I added a Barron Big Air Kit last month, that really added more power and a louder sound, then I added a Cobra FMS yesterday to help with the modification of the air box.
Then after reading every post on the drilling of the exhaust I went out and bought the extension and drill bit.
It really only took less than a minute to drill it out. Then a quick start and poof, the round metal plate blew out.
The sound is deeper at low rpms, like others have said, but not too loud. I took it for a quick spin to the gas station, but will give it a good try Monday morning on the way to work.
Thanks Boomer for your photos and explanation.
I also added the Rivco lighted mirrors last week, had an issue hooking them up, had to get some help, but now I really like them.

Another convert joins the gang

Been thinking about this, but didn't want to be bothered taking the muffler off to drill out the exhaust behind the converter. Saw Boomer's great pics and how-to on using a hole saw from the rear, and the ease of it convinced me. Did it this morning (bought the wrong size hole saw adapter, didn't fit my extension, had to return it and get the right one this a.m.). I echo Boomer's advice. . . . get a really good bit! This is 300 series steel, and its really tough. I couldn't get through it with the crummy Milwaukee's Best bit I bought, and ended up putting a titanium big bit on the extension and making five 3/8" holes in the plug.

Took it for a spin right after, and what a nice difference! It is not any louder with just the holes drilled out. It did not pop on decel for me (like it apparently has for some others). It does pull more strongly through the power band in lower gears, and the mod eliminates the chug starting out or laying on power on corners. I love it, and don't have the slightest bit of remorse.

I have the K&N air filter, have not drilled out the air box, FWIW. So the bike should have better air flow going in, and now less back pressure on the valved going out.

Ski Machine
07 Black n chrome Tourer
I admit it, it was me. I let the dogs out.

Another convert

Finally decided to drill the exhaust not so much for sound but to see if I could dupilcate the smoother feel Boomer talks about. Sure enough, I experienced the same results. Drilling the exhaust combined with the K&N filter that was already in place worked out to be a good combination.

Drilling the Exhaust

I am dying to drill the exhaust on my bike, but possibly being the least mechanical person on the planet, I KNOW something will go wrong and I will regret it.
I leave for work at 5:00 am, and at that hour I am sure the neighbors are grateful for the quiter sounding stock pipes, but I am dying for a louder sound out on the road, especially when someone with pipes roars by making me feel ????? I guess I feel exhaust envy. ;)

just drill 3 holes

The hole saw bit didn't work for me, so I initially drilled out just 3 holes (1 left, 1 center, 1 right), using the 5/16 inch drill bit on the extension. It improved the torque in the first three gears, and didn't change the sound at all. A week later, I decided to drill 2 more holes (top and bottom of the exhaust plug), and I can't tell any difference in the low end torque, but it does sound louder at idle and at low speed. Not Harley loud; just a louder, lower rumble.

So if you want to keep the effect of the big muffler, but gain some of the benefits of drilling it out, you might just try drilling a few holes, first.

Ski Machine
07 Black n chrome Tourer
I admit it, it was me. I let the dogs out.

Just five holes

Are you still happy with this or have you drilled it all out now?

Not mechanically inclined?

Most people think they can't do something, however I once showed my brother in law how to fix a broken valve tappet on a 75 Oldsmobile and from then on he started fixing everything. He said I never realized that I could do something until I did it. He reads up on how to do something and talks to people before starting a job and then he does it. We thank people like Boomer for showing us how, it also saves us a lot of money we can spend on bling!

not to worry....

You are not the least mechanical person on this planet, I am and I drilled my pipes as well.... if you scroll down you will find the video I made while drilling the exhaust.... it took more time to put that video on Youtube than to drill the exhaust....
And for the noise..... well.. it realy is not that bad... in fact, I changed to V&H 2into1 pipes a few months later...

Good luck.....

Rob - in the Dutch mountains....