I installed Fullsac 2.25" OEM (non-CVO) baffles in my wife's otherwise stock '21 Tri-Glide this weekend. The install was straightforward and very easy. It honestly took longer to get the body off than it did to install the baffles.

Trike with the body off: It is technically possible to do this mod without removing the body; however, it is 1000% easier with the body off. There are a total of 8 bolts holding the body to the frame, 6 inside the trunk and 1 under each side cover. The body probably weighs around 100 pounds, but is awkward to lift so have someone available to help lift the body on and off as you have to lift the body a couple feet up to clear the frame. Each can (muffler) has 2 bolts at the rear holding the can to the frame mounted bracket and a clamp up front. The farthest rear bolt on each can is nearly impossible to reach with the body on even with ratcheting mini wrenches.


I used a miter saw with a Dewalt abrasive metal cutting wheel to cut the tips off the cans. Each can took roughly a minute to cut.


I cut each can about an 1/8" behind the rear mount of each can.


The guts of the stock tapered cans. The fiberglass packing material can be reused with the Fullsac baffles, but must be cut to 9" overall length if you choose to go that route.
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Side shot of the factory "baffle". Notice the crimped "X". That is what a lot of people remove on the stock cans. With the "X" in place the exhaust travels around the outside of the can and has to pass through the holes drilled in the body of the "baffle". Removing the "X" allows the exhaust to flow straight out of the end of the 1 1/2" "baffle". I haven't done that mod and have no clue how much it affects the sound and performance of the trike.


Rough fitment of end cap.


Inside of stock can with factory guts removed.


Stock cans reinstalled with the Fullsac baffles installed. The 1/2" bolt directly in front of the Fullsac endcap (black) is the bolt that is nearly impossible to reach with the body installed.


A note on the hole size for the screws on the baffles/end caps. The instructions say to drill the holes out to 3/8". I choose to drill all holes to 1/4" then only the 1 or 2 holes that had a small misalignment to 5/16". You could definitely drill teh holes to 3/8" without any repercussions, this was a personal choice that I made.

Overall, I would give this project a 3 out of 10 on the difficulty scale. If you have basic hand tools and can drill straight holes, it is straightforward enough. I have not purchsed a tuner yet and the trike is currently running on the factory tune. I did have a check engine light for the 1st hour of riding. I checked the DTCs several times during that hour and never found any DTCs. The CEL cleared itself after roughly an hour of riding and did not reappear in the 2 hours of riding afterwards. The CEL may have been from pulling the main fuse as I didn't notice any lean surge, etc during the ride.

I do have a before and after video of the sound but don't know how to post the videos to the forums. If I can figure out to post the videos, I will edit this with the videos.

With the stock cans, the exhaust note was weak at best and had a fluttering quality when the engine was revved. With the Fullsac baffles, the sound is much deeper and much more noticeable from behind the trike. It doesn't sound that much different at idle from the stock cans which is nice is that is your thing. The engine revs MUCH better and seems to pull harder according to the butt dyno. YMMV!

 

Firstly Thanks for posting this as you did it, it really is inciteful how much work is involved with something like this.
Inside the stock mufflers after you cut off the end, is that rust the picture shows?
I think you did a first class job with this. Most important how do you like the new sound?

 

@Mr.Softy Yes that is rust. When we get moved into our new house in a few months and out of this rental, I'll be media blasting the cans inside and out then coating with cerakote.

The sound is much, much better. It is very deep while still being louder than the stock cans. More importantly, the trike seems to run better and definitely revs faster.

 

It surprises me very much that on a new trike the inside of the mufflers are that rusted. Goes to show how little they do to make the trike.

 

Yup, the trike will be 5 months old this month and has been kept in a garage and not ridden in the rain a single day since we bought it new in May 2021. Imagine what normally ridden bikes look like on the inside.

 

The moisture in the exhaust comes from the air the engine takes in. If the air is 50% or even 20% humidity that % moisture goes into the combustion chamber and out the exhaust. Some will naturally collect inside the muffler as the exhaust gases cool especially after the engine is shut off.

 

Not exactly. As long as the exhaust is above ambient temperature the moisture in the air (humidity) stays gaseous. Once the temp drops outside of the exhaust the residual moisture inside the exhaust condenses inside of the exhaust (doesn't matter if we are talking head pipe, cans, etc). Think of a taking a cold can out of the refrigerator and setting it on the counter, same concept but in reverse. It is also why you will nearly always see water trickle (or stream) out of the exhaust on a vehicle after it is started in the morning.

Passing humid air through an engine doesn't cause the rust, but something to think about, the hotter the air, the more moisture it will hold (the saturation to super saturation point in chemistry), ie: the relative humidity inside the exhaust will be higher than outside (barring rain, etc) and when that air cools off it will condense more moisture than the same air outside of the exhaust.

One last thing, moisture in the air does have an effect on the internal combustion process but that is a totally different topic and is unrelated to rust inside the exhaust (assuming the engine is running properly and hasn't been hydrolocked, blown a head gasket or cracked a head/block on a water cooled engine, etc.).