Quiet replacement muffler?

[fastpakr]

My 82 750 came with an unknown brand of 4-1 header and a SuperTrapp muffler with no muffling ability whatsoever. I've posted some pictures on my Cardomain site. If anybody knows what I could use to either quiet the muffler that's on it (at one point somebody told me that there were 'discs' that could be added to the SuperTrapp unit to quiet it down although I've never found out more about this) or to replace it with something that wouldn't require re-jetting but be significantly quieter, I'd be ecstatic. As is, the bike runs fantastically but is disturbingly loud when a load is placed on the motor (especially at upper RPM). Thanks!

Pardon the cosmetic condition of the bike - that will be this winter's project.

Link to pictures

[Jethro]

If you already have that bike running well with the SuperTrapp I would imagine it has already been re-jetted for a less restrictive pipe. You can buy a nice V&H canister pipe from Dennis Kirk for around $350. It would probably be quiter. I don't know if you can repack SuperTrapp cans...

[fastpakr]

I'm trying VERY hard not to replace the whole exhaust system. Despite appearances, the physical condition of the header is quite good, just needs a new coating (I'm planning on a ceramic coat later in the year when I can justify spending the money).

I realize the bike must have already been re-jetted, that was actually the reason for my concern about putting a quieter muffler in place - I was concerned that it might be too restrictive for the current carb settings.

[Anonymous]

(at one point somebody told me that there were 'discs' that could be added to the SuperTrapp unit to quiet it down although I've never found out more about this)

You have it backwards - you remove discs to lower the sound levels. So you already have everything you need to start dropping the noise. Just pull the screws holding the endcap in place and remove one disc at a time and see what it does. It is wise to use anti-seize on the screws to help with removal next time.


Mark

[fastpakr]

Hmm... something's not quite right. As you can see in the picture, there is no endcap at all?

[fastpakr]

Hmm... something's not quite right. As you can see in the picture, there is no endcap at all?

OK, so after further research I'd need to come up with:
4" SuperTrapp Tuneable Disc 12-pack 404-6512 $30.02
4" Closed End Cap, polished stainless 406-3046 $17.77
4" Bolt 6-pack (1-20 discs) 404-7206 $13.32

Those are list prices... looks like it'd be about $50 through Summit racing. Not that bad, but if anybody has or knows where to get used discs and an end cap I'd be all ears.

Thanks for all the help, guys!

[Anonymous]

Hmm... something's not quite right. As you can see in the picture, there is no endcap at all?

I have to confess I never looked at the pics before replying...

From the one shot, it looks like the "competition" end cap is installed. It allows straight through flow as well as through the discs and is LOUD, as you have discovered. I would start with a good 8-10 discs on with a regular end cap in place and work up from there. It is not uncommon for people to end up with 18-20 discs in place, so don't be afraid to stack them up. You will likely find that your jetting is somehwat rich after choking things down enough to get the sound down. Repacking the canister portion would also help some with the volume levels.

Those are list prices... looks like it'd be about $50 through Summit racing. Not that bad, but if anybody has or knows where to get used discs and an end cap I'd be all ears.

E-bay continuously has listings for packs of the discs and end caps. Just search on "Supertrapp" and you should find lots available.


Mark

[fastpakr]

There's no end cap on there at all right now. I looked at eBay, but only found one listing that was really a savings over buying through Summit. That listing is for a used muffler with the endcap, bolts, and discs still on it. If it turns out to be the right size I'll grab it and resell the muffler to make up for a bit of the cost.

[stiksave]

I've got a set of disks that came with my bike. The super trap was doa and the header. I still have the disks in my extra stuff box. They're yours if you want them. cokonro@yahoo.com.

Chris

[fastpakr]

Thanks, I'll probably take you up on that. Got to figure out an end cap too - hopefully this eBay auction will pan out (it's a bit cheaper than buying the cap and bolt set new).

[fastpakr]

I've got a set of disks that came with my bike. The super trap was doa and the header. I still have the disks in my extra stuff box. They're yours if you want them. cokonro@yahoo.com.

Chris

Hey, if those are for a 4" muffler I'd love to have them (just sent you an email). I found another eBay auction this morning and grabbed it, but will probably need a few more disks to keep it as unrestrictive as possible.
Auction link
Thanks!

[stiksave]

Fastpakr,
You should the disks on Monday. Enjoy!

Chris

[fastpakr]

Looking forward to it. Got the cap, bolts, and 8 discs from the eBay seller today and just bolted them on (haven't ridden it yet). Thanks again!

[fastpakr]

Update... Not long after my post from last year, I hit a bit of oil mid-turn and went into a low speed low-side. No major damage, but it scraped a hole in the side of the muffler. What mufflers can be used to replace Supertrapp that's on it? I see plenty of things on eBay from newer bikes, but I'm not sure how to find the details of the replacement mufflers so I can determine what would actually fit.

[gremlin]

if you have a welder or a brasing torch handy. you can repair the hole. it will get you by till you can find a replacement. just cut and bend to fit over the hole weld or brase in place.

it will look ugly but the sound will be better.