Exhaust

[Tkosanic]

I have heard of people gutting or straight piping their factory exhaust. How would you go about this? I.E. pulling the exhaust apart, gutting etc. and would you have to re-jet the carbs or no?

[Trader]

Now why would you want to do that and ruin a perfectly good bike?

 

Touring bikes are not supposed to sound like they belong on the track.

 

Besides, there's already to many idiots around making noise on bikes!

[Freebird]

Deleted my post. Just realized that this is for a first gen. My information was useless.

[dingy]

I have heard of people gutting or straight piping their factory exhaust. How would you go about this? I.E. pulling the exhaust apart, gutting etc. and would you have to re-jet the carbs or no?

 

In general, the consensus here seems to be you don't have to re-jet.

 

The 83~85 had 117.5 mains, then the 86-93's went to 125 mains.

 

Go slow on gutting mufflers, I have a set I pulled all the last baffle out and they are as loud as about any HD, don't use them much.

 

Gary

[mbrood]

An interesting option. You would need to gut the collector (do away with it ideally) and then gut the mufflers. Now you have a free ported V4 that you probably won't be able to start in your neighborhood due to city, county and state regulations. You WOULD need to rejet as you wouldn't have the designed backpressure of the standard exhaust. Real testing would need a dyno and a skilled technician to get the jetting back to a mildly rich setting but it's certainly able to be done. Please remember that sale value would be lowered considerably and proper mufflers reattached to make any sale valid. Most state vehicle inspections would likely be a real problem.

 

Perferating or removing the last muffler plate will increase the sound dramatically while still holding the looks and probably legal decibel limits.

 

A guy a few blocks away runs an open Triumph 650 and it's EASY to tell his work schedule. BUT he has a set of mufflers he can throw on when he needs to.

 

I just figure, if it scares the dogs, the neighbors can't be too happy.

[Tkosanic]

You talk about removing the last muffler plate....the piece that dramatically tapers down at the back of the muffler? I am not looking for extreme loud just to give her a bit more bark. How would you go about removeing that. Just cut it off or does it seperate?

[mbrood]

Most guys start with a couple holes drilled in the plate to see what they have so far... It's an easier route than straight pipes.

[dingy]

Attached are some pictures of a modified 83~85 muffler. I have been happy with removing the cone and a couple of 1/2" holes in last baffle though.

 

The gutted set were only on my modified bike and they did run OK on it. As mbrood stated though, this much removal of baffles probably would require some carb work on a stock bike.

 

Gary

[Tkosanic]

My question is the cone. do you have to cut it off or is there and alternate way of removing it?

[johnnydemonic]

I gutted my mufflers by simply cutting the tapered end cap off, they look like megaphones now.

I removed all the baffling and got some universal megaphone style baffles to replace the stock stuff I ripped out.

 

I did not gut the collector, which I believe provides some slight muffling action as well.

The tone is mellow, not too loud, unless I am really kicking it in the flanks, but far more pleasing to MY ear than the FFFFFFFFTTTTTTTHHHHH sound it used to make.

 

It sounds like an actual motorcycle now, instead of a farting cow.

 

I have seen others simply drill out the spot welds on the end caps, gut the mufflers to the extent they desire, and then spotweld the end cap back on.

 

I liked the megaphone look.

 

While I had my mufflers off for the gutting procedure, I stuck some temporary straight pipes on in their place...THAT was LOUD!

Imagine two of the loudest harleys you can think of.

 

I did NOT rejet or spend any time on a dyno, pray to any unholy dark gods, spend thousands on tuning, etc...BUT...I also did NOT completely gut the system, and I DO have baffles back in there...just not stock baffles.

 

The danger here is, of course, that opening up the exhaust system creates a lean fueling condition which if severe enough, can cause overheating and even melting of important internal components, like pistons and valves.

 

I have been riding it for years now that way (up until about a year and a half ago, when I tore it apart for different reasons) without any ill effects mechanically, without being shot at by the neighbors, (or even flipped off), I haven't had the police muffler task force hunting me down, my face is not on any wanted posters at the local post office, cats and dogs are not lying together in unholy union, babies and old women do not spontaneously weep when I pass...

 

I am certain that if I DID completely gut the exhaust system or switch to straight pipes, I would need the assistance of a skilled carb tech/black magician as well as a pact with the devil, signed in my blood, to get the jetting correct...

 

or maybe just a wideband 02 sensor and gauge, about 3 or 400 bucks at most performance supply shops, plus the price of welding in a bung or two to the modded exhaust, an assortment of jets plus the time and patience it would take.

 

Disclaimer: I do not recommend doing this. (your results may vary)

Also, I live in washington state, there is no sort of vehicle inspection here that a motorcycle is subject to, your state may have more stringent regulations.

 

There are a few threads here with a pictorial guide, if I recall.

 

Good luck!

[dingy]

My question is the cone. do you have to cut it off or is there and alternate way of removing it?

 

I used a band saw to remove the cone. I think it is spot welded several places around the seam.

 

Gary

[JohnT]

So, how rough will mine sound if I simply gut the collector? As bad as this sound I do want mine a little throatier. OK rumblier and a bit louder, however you want to look at it. Not a lot.

And how much will this impact my jetting / running? Stock pipes intact. They are in mint shape with the turn down ends. I like the looks of them.

[Venturous Randy]

So, how rough will mine sound if I simply gut the collector? As bad as this sound I do want mine a little throatier. OK rumblier and a bit louder, however you want to look at it. Not a lot.

And how much will this impact my jetting / running? Stock pipes intact. They are in mint shape with the turn down ends. I like the looks of them.

 

The baffles in the collector do not re-route the exhaust as you would think a baffle would do. But, the baffles in the collector is sheetmetal that has some small holes, like a screen that lays against the walls of the collector. This gives a slight dampening effect on the noise and by removing them or at least removing the loose ones, I don't think you will change the loudness very much. I have Jardines on mine that are at least 14 years old and have gotten a bit louder, but I don't think that removing the collector baffles made much difference.

RandyA