Table of Contents

REF: Carburetor, Intake Manifold & Exhaust

Exhaust Leaks

You can put your hand near the pipes at likely places for leaks (exhaust ports, any joints) and see if you can feel air escaping. 1)
But, be careful not to burn yourself on the pipes.

Smoke Test

When oil is added to the combustion chamber, the result is smoke coming out of the exhaust.
The oil burns and comes out as smoke. 2)
The smoke should just come out the ends of the mufflers.
If smoke is coming out anywhere else, that's where your leak is.

Test one cylinder at a time.

  1. Pull a spark plug.
  2. Add a spoonful of standard motor oil in the cylinder.
  3. Reinstall the plug.
  4. Fire up the engine.
  5. When it starts to smoke put a rag in the exhaust pipe and look for leaks. It helps if you have a buddy hold the rag


Baffles, Torque Cones and Lollipops

Baffles

Drilling a Hole in the Baffle

A lot of people drill the baffle plug out of the standard mufflers.
But, use at your own risk.

Issues with doing this mod include;
Tuning:
It can create tuning issues due to “wave reversion”. problems. 3)

Unwanted noise:
Some say it will make a chirping sound if you drill the whole baffle plug out.
Others say it will only make the whistling / chirping sound if you take the whole 1-1/4“ inch baffle plug out. 4)
And a 3/4” hole through it won't make that sound. 5)

Overall sound:
Reportedly, the bike should sound better than the stock.
This mod adds volume, and more low end 'sound' than the stock version. 6)

Failed inspections:
Once the muffler baffles are drilled, it can easily be detected that you have 'tampered' with them.
Depending on where you live, your bike may not pass inspection due to this mod. 7)

This was done with a 3/4“ hole saw on a 10” drill extension. 8)

If exhaust is installed, make sure the set screw in the extension is tight so you don't drop the hole saw inside it. 9)
Drill out the center of the baffle (3/4“ hole saw used here). 10)

Other variations:

Holes drilled around the baffle 11)

Modifying standard mufflers for better flow and sound

The Gronk Muffler Mod

Article by gronk62 of the XLFORUM 12)
This mod is for when you don't like having loud pipes or the 'chuff chuff' sound the standard mufflers make.
The mod gives a great sound with zero metallic blat! 13)

OEM mufflers are quite restrictive so the baffles were removed with a 1-3/4” hole saw and the holes were drilled bigger.
(enlarged to 1/4“ or 6mm and also added a couple of extra rows on the outlet side of the baffle plug).

The baffle plug must be left intact for the guide to sit on.

Doing this mod helps to increase the gas flow and allow a more fuller and deeper sound without being too loud.
But, it is unlikely to give much in the way of performance increase.
Although your bike may feel slightly stronger at low to midrange revs.

You'll need flare the ends or have a muffler shop do them for you so it fits snug back in the the hole made by the hole saw.
Then weld them in taking care not to blue the chrome.
It helps to wrap a wet towel around the area to be welded to keep the chrome cooler.

You'll need to make a guide for the hole saw.
The guide slides down and stops at the baffle center piece.
The hole in the guide is for the pilot drill in the hole saw.
Hole saw and home made guide. 14)Guide installed, ready for the hole saw. 15)
The top baffle is standard. 16)Note when welding them back in,
They don't have to be welded the whole way round.
A couple short welds will do. 17)

Removing the Baffle

Making Your Own Baffles

Based on an article by chickenhawk of the XLFORUM 18)

This is an easy and cheap way to create some decent Cycle Shack & Screaming Eagle type baffles for a cost of around $7 per baffle.
With this type baffle allows for fine tuning for great performance.

If your slip-ons are missing the baffles, you can gain some midrange back and get a nice deep sound by adding baffles.
The ones below are adjustable so this is a good starting point.

Modifications / Fine Tuning:
There are so many ways you can mod these baffles. Here are some ideas.

Note: Check the I.D. of your slip-ons to get the right size pipe to use.
Most pictures below are of a 2“ baffle/pipe that was later replaced with 1-3/4” pipe.
The 2“ pipe may not leave enough room between slip-on and baffle for air to be diverted and it may be a bit restrictive.
(if you don’t leave the diverter/tongue more open which reduces the fine tuning possibilities)
If you have very little midrange lag and just want less harsh sound of open pipes, then the 2” pipe should work fine.
Just leave the diverter more open and fine tune as needed. 19)

Buy a short piece of pipe for the baffle. Auto parts stores or your local muffler shop (cheaper).
Muffler shops can also flare the ends for you. 20)

Cut the slot for the diverter with a hacksaw.

Cut for the diverter/tongue.
To get the rounded looking cut for the diverter, start about 1/2“ to 1” from one of the bends.
Cut at an angle. Stop when you are around the half way mark.
A rounded cut should help the diverter follow the contour of the inside of the baffle when it’s bent down.21)

There are many ways to press the diverter down so use what you have at hand. But remember, this is exhaust pipe so it’s not the thinnest stuff to work with.
You can set the bending tool perpendicular with the diverter tab. Or, you can lay the bending tool horizontal with the diverter tab and hammer that down.

To get the bend started you can just hit the diverter tab with the hammer to start the bend. Hacking away with the hammer for the entire bend won't be any faster than using a dowel.
Start with the hammer to get the lip down below ‘level’. Then use the dowel for the rest (saves time and finished product looks less chopped).

Notes:
Placing the baffle on flat surface of a vice works good.
Hold the baffle down and against the back of the vice clamp and the baffle won't slide around. Keep checking the other side of the baffle to make sure you are not flattening it as you pound on it.

A piece of 2×4 also works good but requires more effort to hold it straight. Regardless of method, in the end result you want both baffles to match the amount of air getting past the diverter.

Also, If you try and 'mostly close' the diverter, but it seems to stop bending down, check your initial cut line.
You may need to get your hacksaw back out and cut a little further down the baffle.

And, on the 1-3/4“ baffle, try to bend the diverter down so there is about a 3/16” to 1/4“ gap between diverter and the inside walls of the baffle.

Depress the diverter. The trick is to get the depression started.
Then use a dowel or a small diameter pipe for the rest of the bending.22)

Drill holes in the baffle to let the diverted exhaust get back out.
Tape was used below to mark the hole locations.
The tape, along with a punch, also helps eliminate the drill bit from slipping when starting the hole.

The holes below are 5/16” (a little larger than the standard 1/4“). But, they can be sized for your specific requirements.
However, you may want to start with 1/4” holes.
From there, if you want more sound or more air getting through (without affecting your current power in low to mid rpm range),
Drill a quarter of the holes, or every-other hole, out to 5/16“.
Drill more as needed after testing if you like.

Standard baffle 23)Holes in the baffle partially drilled out. 24)

Sound varies between bikes also.

Note: if your baffles have a 1/4” space between the outside of the baffle and the inside of the slip-on,
You may only be able to use a single layer (not overlapping) of the muffler packing or the baffles won't go back in.
Also, wrap the sheet of muffler packing as tight as you can get it.

8 columns of 4 holes around the entire 2“ baffle were drilled. But, only 7 columns of 4 holes around the entire 1-3/4” baffle.
The holes are spaced apart about 3/4“ apart in each set.

Lastly, drill the mounting hole for the bolt that connects baffle to exhaust pipe.
Be sure that you drill this hole on the opposite end of baffle that the bend of the diverter is facing
(the exhaust needs to go up the ramp - or just remember the drilled baffle holes are towards the exit of the exhaust).
Make sure your baffle will mount fine where you drill this mount hole.
The drill size of the mounting hole is the same size of the mounting hole in your exhaust.
If you need to drill a mounting hole in your exhaust, then make sure the size of hole corresponds with the bolt you are using for mounting.

Drill hole locations are easily marked using tape 25)

Finished Products:

1-3/4” Baffle 26)
2“ Baffle 27)

Torque Cones

Torque cones are basically (choke down venturi effect) drop in cones that go in the engine side of your pipes.
They rest against your exhaust port.
Prices can be from about $10 from Mid-USA, $30 kuruakyn and $85 from Sampson.
They give some bottom and mid range back as well as help to smooth out the sound. 28)

Torque Cones 29)

Lollipops

30)

Thunder Monsters (fancy lollipops) 36)

Results

The results of using lollipops are concurrent with each other for the most part:

Copyright Notice - 42)

Some people are not at all sold on the idea of using lollipops. This gets into another one of those debates over using better pipes rather than drags for street use, although lollipops will give you better lower end torque which is a proven improvement for street use. Some are completely sold on running drag pipes which will have to be in another discussion.

Different Materials Used

Several different methods and materials have been devised for lollipops all using 1/4” nuts/ bolts to secure them in the pipes. Click on an image to enlarge it:

Simple and easy but loud! 47)

* Below is a list of some different materials used by XLFORUM members:

Fabrication for 'Tunable' Lollipops

  • You want to 'cone' the washers to a depth of 1/4”. I did this using a 13/16“ socket and a 7/16” socket in a vise. I found a long 'cheater bar' gave me the needed 'oomph' to 'cone' them nicely. Next, I lightly chucked the bolts (heads up) into my vise, switched on the MIG, and attached the coned washers to the tops of the bolt heads….taking care that the were centered and straight. I then drilled my hole starting with a 3/32 bit and then a 5/32….and then the 1/4. Do yourself a favor and 'wallow' the hole out just a little bit….you'll need the extra room when inserting the cones! You don't want to use a 1'' bolt with a 1-3/4“ pipe! It just won't fit! Use a Dremil with a cut-off wheel so the bolts quickly became 1/2” long. Always do yourself a favor and thread a nut onto the bolt before cutting it off, because backing the nut off AFTER the cut is made will 'clean' the threads for you….making assembly a breeze. You want the 'cone' to be pointing forward (towards the engine!). You will also want in the neighborhood of a 30 degree turn in the washer's relation to the tube. Also, try and get both cones at the same angle in your pipes. I found using a screwdriver placed in the 'eye' of the washer and a 7/16 wrench did the trick.
  • Speaking of 'favors', get a magnetic probe (or pickup) tool. Not only is it great for getting nuts, bolts, etc. out of tight places where fingers cannot fit (and eyes cannot see), but I found I needed it to get the Cones in place. Fingers and pliers were just not working, but the magnetic probe held it at the PERFECT angle to slip it down the pipe and into the hole. 56)

Placement of Lollipops

Pics of Lollipops Installed

lollipop_by_dave76lollipop_by_fdny37lollipop by smokerider
Washer welded to 1/4” bolt61)Thumbscrew bolt62)Washer welded to 1/4“ bolt63)
lollipop_by_rooster77lollipop_by_xllent01
Washer welded to 1/4” bolt w/ bolt inserted into washer64)Eyebolt 65)

Patriot Defender

Dims: 66)
1-3/4“ diameter out of the heads.
Out to 2”.
Then 2-1/4“ to the collector.
The collector is probably 2-1/2” in a megaphone configuration.

Patriot Defender Pipes Pics and Dims. 67)
Patriot Defender Pipes Pics and Dims. 68)

Exhaust Bracket Mods

Exhaust brackets can be fabricated to fit just about any configuration needed.
(especially when using aftermarket pipes)

Mount the pipes to the heads with proper torque.
Allow them to gently sit on their own.
This allows for vertical and horizontal measurements to be taken from the point where the mount mates to the pipes.

Below is the bracket that comes with the purchase of a set of Thunderheaders.
This particular bracket was slightly too low and recessed to fit on a 98 1250.
(it may have been fine for stock 1200 heads)
The plate on the bracket was cut into and another plate was welded to it to extend the mounting holes.
With the extra plate simply welded on top of the original one, the height worked out as well.

Thunderheader bracket mod. 69)



44)
eyebolt2_by_bass_thrasher
45)
lollipops_by_rooster77
46)
lollipops_made_by_xldaver
61)
photo by dave76 of the XLFORUM
62)
photo by fdny37 of the XLFORUM
63)
photo by smokerider of the XLFORUM
64)
photo by rooster77 of the XLFORUM
65)
photo by xllent01 of the XLFORUM
69)
photos by Hippysmack