Drilling holes in muffler??

Sorry guys but I'm really new I can't say it enough, I didn't even take shop class in high school.haha Me and my friend are bobbing my bike and he says til I have the cash to replace my exhaust system I should drill some holes in the end of the muffler to make it louder. Haha I'm just clueless and this sounds crazy to me. Thanks for the help! Maxim I 650 1980

 

If you have the original mega-phone type mufflers and they are in good shape, I wouldn't drill them. They are worth a good bit to somebody and you can get some shorty muff's from JCWhitney for about 30 bucks a piece. Some members have gotten Sportster muff's on Ebay for cheaper.

 

If you drill holes in the Muffler to make the Bike, ... LOUDER, ... you quite possibly may upset the delicate balance of required Back Pressure and need to start fooling around with experimental-type tuning.

These Bikes are CLASSICS, now.
25-years old or older.

Why, ... on Earth, ... would you deliberately ruin an Exhaust Silencer?
Probably worth a couple of bills, ...
When you can simply remove the Silencers ...
Substitute a pair of LOUD "What-ever's"
Ride around making a lot of noise wondering why the bike isnt running right.

Then, just like the Sun rises, every morning, ... in the East.
It will dawn on you.
Ever since the bike started making lots more noise is when it started acting funny.

Stick the Cans you took-off ... back-on ... and,

Badda-bing; badda-boom, ... you're back in action.

 

Listen to your friend. Don't listen to Rickomatic. Drill a whole bunch of holes in your mufflers - that will make it really loud. Then add pods to it. That will increase your horsepower tremendously. In no time you'll have the loudest, non running bike in your neighbourhood. Your neighbours will be really happy!

But really, why would you wreck a perfectly good collector bike by doing something like this to it? If you want loud and obnoxious - trade it in for a Harley. Oh - and ...... no offence intended. Just sayin' !

 

Make it really, really loud by just removing the stock mufflers, and running straight pipes.

Then when the engine blows from being run lean for to long you. Just maybe it will finally dawn on you the maybe somebody actually knew what they were talking about!!

Drilling holes in valuable parts = STUPID IDEA!!!
Selling valuable parts to fund cheap replacement parts for effect= Now your thinking!!

Ghost

 

awww cmon guys... he said he was new, and he also said he didnt think it sounded good. hes just got a friend that had one too many beers before commenting. kid.... its a bad idea. you can get a 4 into 1 with a new tip and sync and test and all that..... until then, let it be quiet. ive had many many many different tips on mine to check different sounds, and they all sounded like a 4 cylinder honda choking on a bone. minus the sarcasm..... these guys on here know what they are talking about..... and although it might ruin any fun or "great ideas" that you may come up with, they are still right 99.999 percent of the time

 

He did take the time to stop, and ask first!
Ghost

 

We assume his mufflers are not bent and rusted. If they are dinged up and rusty go for it. BUT if they are nice. Sell them to someone who would like to keep thier bike stock and take the cash and buy what ever exhaust you want.

MN

 

Hmmmm? A new set of mufflers for a XJ 750 Seca are about $1,200.00. Ouch! Mine were SHOT already when I purchased my bike so I went to a Harley Swap meet and picked up the coolest set of straight through exhaust mufflers I have yet to see with slash cut out on the flared end of the muffler for $25.00 for the pair! Now what problems I am going to run into with them is yet to be seen but they will be louder or the fiberglass packing is going to be drilled out but I have heard before that when drilling out you go with a hole on one side and then a hole opposing directly on the other side, and then top and bottom opposing, probably for balance but time will tell. I am putting Pods on mine but as stated in here earlier that if you keep the CAN (or what ever you want to call it in between the front exhaust pipes and the mufflers it won't matter. Time will tell but then that's what having a bike is all about for me. Who wants to have a bike like everyone elses? Lets have some fun in the process. ))) grunt007, 81XJ750 SecaR, Mi.

 

Thanks for the help, like I said I had no idea. They are in great shape. Only 9k miles on my bike, garaged the entire time. Now to figure a price for them and figure out how to get them off and how to buy new ones haha thanks guys

 

now when you say they..... do you mean dual mufflers? if so, it should be a welded system, and the only place to take off would be at the "h pipe" that connects the two ends to the header. might be another problem for you if you got duals.

 

UH OH! You've set them off now for good. You just thought they were upset about you asking about drilling holes in the exhaust. 9000 miles and garage kept? Here it comes, "That bike is too nice to hack up." You'll be reading that umpteen million times in your near future. So, let's make this fair. Let he who has the cash to purchase this bike and show the owner just how nice it really is be the one to tell him it is. Everybody always says it, but nobody ever wants to put their money where their mouth is...

 

This is crazy. They're your cans, you paid for them. Do what you want with them!

Sure, you could probably get enough cash to replace them with aftermarkets. Yes, if you chop and drill to much you could hurt your bike.

My stock mufflers were drilled when I got my bike! They had 4 holes drilled, evenly spaced around the exhaust holes. I'd guess they were done with a 5/16 bit.

I will say that I've never heard a "stock" exhaust(not drilled) to know the difference in sound. Hell, I don't even know if it would be noticeable. I will however say that it had a decent sound, not like a crotch rocket. And.... IT RAN GREAT that way!

If you do drill them start with a few and not get to crazy.

I actually cut my cans off with a hacksaw and dremel!!!!!!!! I put some harley mufflers on mine. Not because I want it to be a harley but because it was a better look.

 

no ones telling him he cant prince..... they are stating that its not going to be good for the bike. the po of my bike put a 4 into 1 on it, and ive never done anything as far as tuning... you can tell because plugs are black, but thats my stupidity. these guys, although were sarcastic..... are trying to save him from writing his next post as "help, I need new mufflers!!!"

 

I swear, the stupid sh*t people come up with...

 

So sounds like I need to buy a 4-1 and than swap exhausts?

 

Well I have a nice 81 650 Max with 6300 on the clock. the left muff has a dent in it . If its nice I would pay for it. You can bet on that. I have not seen a NOS one on the market yet or I'd own it

MN

 

Yes. 4 into 1 and then tune so the bike runs good. My 82 has duals on it. Was thinking of 4 into 1 with that one as well. You all say big bucks eh? What is my stock dual worth? The headers are a little piitted and the h pipe has seen better days but the muffs are mint

 

What is involve in tuning. Can a person of my knowledge do it? Ha

I found this,
http://bikeadvice.in/tuning-carburetor- ... fficiency/

Is that what you mean?

 

Drill the holes in the muffler and make them wine cork size.

Ride along most of the time nice and quiet then give it full throttle, hit the kill switch for a split second, then bang, all the corks blow out and instant noise!

 

Isn't that why they have different size jets for carburetors? Is it not possible to increase jet size to richen up the mixture to compensate for the extra air flow?

 

It is very possible to rejet, however everyone just changes the main jet and forgets there is both fuel and air jets for low speed, needle jets for mid range etc. Most people haven't got the time and resources to dyno a bike, remove the 4 carbs and rejet, then refit, retest, rinse and repeat. So most home rejet jobs are a compromise.

 

haha, yeah, true that. I understand that there are 4 carbs, but how much harder is it to re jet an XJ than it is to re jet a dirt bike after opening up the air box and exhaust? I mean, it's a pretty common thing to do on dirt bikes, how much harder could it be on an XJ?

 

Most dirt bikes are not CV style carbs. And not many people actually have to do any research to rejet, as there is plenty of professional shops that sell the components and will actually tell you what jets you require to suit the performance bolt ons.

Also there are a lot of people who know how to tune dirt bike carbs.
Here in perth there is not one professional tuner/shop who will rejet your XJ's carbs.

Put a set of non CV style FCR flat slide carbs, and then you will find a few shops who may take lots of your money, but they will get it right.

 

Bingo!

There is a basic set of guidelines that will get you in the ballpark; however it's still a trial and error situation and the rack has to come off for each change. That's the primary reason it's often impractical.

 

Well, as I said before. Different Strokes for different folks. I started in bikes at 13 or 14 years old, went from Cushman to Lambretta scooters as I call them to a Harley 250 customised Sprint, then Hondas, next 2 Triumph 650 Bonneviles, and finally a 2,500 mi. BMW Boxer twin. Of all of them to be honest I had the most fun on the Harley 250 Sprint which I totally modified to a dirt bike with full knobbies, engine was beefed to about the limit and she ran like a scared Comanche. Back then I drove her 15 miles to work each way everyday with the full knobbies on. To me Bikes are made to be a personal Identity based on who owns them. This was one reason why I bought my Seca, because I could see how I could modify it to be what I was looking for in a bike. When I have worked on a engine I like to hear it sound off-just my thing I guess but who care's, I will be 65 in November and I am at the age where I now do mostly what ever I feel like doing. If it lights my fire then I am for it. No dead blood in my body, VietNam tried to do me in being wounded in combat twice and I am still kicking so let the kid just have fun eh? grunt007, 81' 750 XJ SecaR, Mi.

 

I hate to just pee in everybody's cornflakes here; but if they're solid, stock mufflers the internal construction is such that drilling holes around the outlet pipe really won't do anything except provide a whole bunch of entry points for water. It won't allow exhaust to escape from those holes, maybe a little sound, but no "fire." The outlet pipe goes into a baffle about 6" or so inside the muffler; that baffle completely blocks exhaust gasses from getting into the rear of the "can."

The only thing drilling holes in a set of (solid) stock mufflers does is decreases their VALUE. It won't make them louder.

 

I drilled some XS750 cans once, ended up with an idle sounding not unlike a one-lunger John Deere.