Author Topic: HM341 Preservation: WAS: Baffle/stuck steel wool removal  (Read 11325 times)

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Offline edwardmorris

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HM341 Preservation: WAS: Baffle/stuck steel wool removal
« on: September 19, 2013, 04:00:47 PM »
If anyone's been following the Project Ice Cream thread, you'll be aware of my most regrettable purchase so far, a set of rusty holey hm341s. I'm trying everything I can to salvage these for use, but I may be making things worse. I know for a fact that there is chunks of who knows what in the pipes, and there is obstruction when I tried to snake it with a thick wire (feels spongy like a stuck wirewool brush which the seller said he used to clean them up a bit). It won't come out the header end, and the tail end seems to have a metal wall with a small outlet. I have no clue what was behind that wall, but I do know there is something clanking around in there and refusing to come out. How do I remove the end so I can empty these pipes?
« Last Edit: September 22, 2013, 04:44:25 PM by edwardmorris »

Offline Old Scrambler

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Re: HM341 Baffle removal
« Reply #1 on: September 19, 2013, 04:56:38 PM »
The internal baffles are spot-welded to the mega. Early 341s have 2 washer-type supports for the central perforated pipe..........later 341s have 3. You can tell by the placement of the spot-welds that cause little dimples to the outer mega. If the pipes sat for a long time, they may have one or more chunks of rusty soft metal inside. I remove most of the debri with compressed air.

If you need to see what is inside, try to find a shop with a flexi-scope. Sometimes the local NAPA guys and gals will help.
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Offline crazypj

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Re: HM341 Baffle removal
« Reply #2 on: September 19, 2013, 04:59:06 PM »
You can use a hole saw to cut through the end but it rarely does much good
May be worth trying though if you have no other option
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Offline nccb

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Re: HM341 Baffle removal
« Reply #3 on: September 19, 2013, 05:18:34 PM »
The internal baffles are spot-welded to the mega. Early 341s have 2 washer-type supports for the central perforated pipe..........later 341s have 3. You can tell by the placement of the spot-welds that cause little dimples to the outer mega. If the pipes sat for a long time, they may have one or more chunks of rusty soft metal inside. I remove most of the debri with compressed air.

If you need to see what is inside, try to find a shop with a flexi-scope. Sometimes the local NAPA guys and gals will help.

I always thought the 341s just had a diffuser that you could remove?

Offline Old Scrambler

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Re: HM341 Baffle removal
« Reply #4 on: September 19, 2013, 06:16:41 PM »
That is commonly known as the End-Cap. The central ring of the cap nests into the 'pipe'.
Dennis in Wisconsin
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Offline wpadgett2

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Re: HM341 Baffle removal
« Reply #5 on: September 19, 2013, 06:30:09 PM »
    I can't help you with removing the baffle but as far as removing the rust, I brought a pair of Mac 4-2 pipes back from the grave using the electrolysis rust removal process... It seams to work really well with chrome!

Offline edwardmorris

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Re: HM341 Baffle removal
« Reply #6 on: September 19, 2013, 07:04:45 PM »
    I can't help you with removing the baffle but as far as removing the rust, I brought a pair of Mac 4-2 pipes back from the grave using the electrolysis rust removal process... It seams to work really well with chrome!
Same process that is used for gas tanks? How did you get them to soak? I'll have to look into this once I get whatever is stuck in them out...thanks!

Offline wpadgett2

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Re: HM341 Baffle removal
« Reply #7 on: September 19, 2013, 07:14:02 PM »
I used a plastic 55 gal drum that i cut the top off of. I used it for probably two weeks straight to clean all rust off my summer project.

Offline Tews19

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Re: HM341 Baffle removal
« Reply #8 on: September 19, 2013, 08:45:51 PM »
Where did you buy the pipes? Ebay or cl? If ebay you may get money back if item was listed incorrectly.


Anyway you can post pics of the pipes?
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Offline edwardmorris

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Re: HM341 Baffle removal
« Reply #9 on: September 19, 2013, 08:45:59 PM »
There is definitely something jammed in there, of the 4, 3 of the pipes are dropping crumbs when shaken enough and I tried to blow it out with a shop vac, no luck, The airflow is pretty good on the 3, but the 4th one not so much. Electrical snake, camp fork stretched out, even a hose couldn't grab onto the lump of steel wool in there. So frustrating. Any ideas how to get it out?

Offline edwardmorris

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Re: HM341 Baffle removal
« Reply #10 on: September 19, 2013, 08:52:31 PM »
Where did you buy the pipes? Ebay or cl? If ebay you may get money back if item was listed incorrectly.


Anyway you can post pics of the pipes?
Pix will be up soon, still on my phone, give me about an hour.

Long story on the purchase, I bought them off of Craig's list, but the pictures were misleading. The guy was all the way out in Norfolk Virginia and refused to ship them. I have a buddy who's retired folks in Williamsburg agreed to drive out and pick them up, then ship them out to me. Needless to say I had to pay quite a bit, just don't even ask because OUCH! Been working day+night shifts last 3 days, taking a break tonight and back to the grind tomorrow till I get outta this hole....

Offline Stev-o

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Re: HM341 Baffle removal
« Reply #11 on: September 19, 2013, 08:57:46 PM »
Hey Ed - it is very common for old exhaust to have rust inside and to hear it rattling around.
Some rust can even get blown out when starting the motor after setting for a long time.
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Offline 754

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Re: HM341 Baffle removal
« Reply #12 on: September 19, 2013, 09:01:18 PM »
If its steel wool, leave it in..willblow out in a thousand miles..
But how could it get in there..?
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Offline edwardmorris

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Re: HM341 Baffle removal
« Reply #13 on: September 19, 2013, 09:07:35 PM »
If its steel wool, leave it in..willblow out in a thousand miles..
But how could it get in there..?
PO tried to clean the insides with it after scrubbing the outside to make them look pretty in the pix.

Offline edwardmorris

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Re: HM341 Baffle removal
« Reply #14 on: September 19, 2013, 09:09:18 PM »
Here are some pix

Offline edwardmorris

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Re: HM341 Baffle removal
« Reply #15 on: September 19, 2013, 09:10:49 PM »
The header ends are solid

Offline 754

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Re: HM341 Baffle removal
« Reply #16 on: September 19, 2013, 09:14:55 PM »
If there is steel wool inside there, i dont think you would "hear ". It when shaking the pipe.
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Offline Spanner 1

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Re: HM341 Baffle removal
« Reply #17 on: September 19, 2013, 09:16:53 PM »
341 pipes do not have a removable baffle.... have either 3 or 5 offset 'disks' welded in place and offset from each other. So, a wire 'snake' will not pass thru' the pipe from either end  :(. If some steel wool or whatever is 'lost' between any of the baffles then it's 'good luck' with trying to get it out IMO... sorry for the Debbie Downer !
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Offline edwardmorris

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Re: HM341 Baffle removal
« Reply #18 on: September 19, 2013, 09:18:43 PM »
If there is steel wool inside there, i dont think you would "hear ". It when shaking the pipe.
There is crap trapped between that and the tail end. Other three, when I shake and tap, junk is falling out through both ends, but not on this one, stuff is only coming out the tail end and that's what I hear...

Offline crazypj

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Re: HM341 Baffle/stuck steel wool removal
« Reply #19 on: September 20, 2013, 06:41:30 AM »
When the ends are rusted through like that the silencers are done for.
May as well cut the ends off completely and have some removable stainless steel or alloy caps made
The pipes may be good but it's mainly the chrome and nickel underneath holding them together
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Offline bjatwood

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Re: HM341 Baffle/stuck steel wool removal
« Reply #20 on: September 20, 2013, 08:13:30 AM »
Quick Question, Exactly how much $$ did you have to "pay" for those pipes?
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Offline Tews19

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Re: HM341 Baffle/stuck steel wool removal
« Reply #21 on: September 20, 2013, 08:52:12 AM »
I think he is anxious to get the bike up and running and making snap purchases.... I gave away pipes in a little bit better shape. Hopefully not much.. I will reiterate what others have said... Stop buying stuff for now.. Get what you have sorted and then move forward...

You state no air coming through the one pipe... Could it be the one cylinder is not firing?
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Offline edwardmorris

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Re: HM341 Baffle/stuck steel wool removal
« Reply #22 on: September 20, 2013, 09:43:33 AM »
I think he is anxious to get the bike up and running and making snap purchases.... I gave away pipes in a little bit better shape. Hopefully not much.. I will reiterate what others have said... Stop buying stuff for now.. Get what you have sorted and then move forward...

You state no air coming through the one pipe... Could it be the one cylinder is not firing?
I'll admit the pipes were a snap purchase because from what I read everywhere these are very hard to find and crazy expensive. These aren't on the bike, I did a quick test with a shopvac. Air does flow through them, just on this one it feels very slow, as if there is a clog.

Offline edwardmorris

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Re: HM341 Baffle/stuck steel wool removal
« Reply #23 on: September 20, 2013, 09:53:06 PM »
Been searching around, and turns out steel wool is highly flammable. Not sure if the pipes get hot enough to burn it out but how terrible would it be to just set it on fire while the pipe is out?

Offline edwardmorris

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Re: HM341 Baffle/stuck steel wool removal
« Reply #24 on: September 21, 2013, 09:21:05 PM »
Got the bastard! Took it to a local auto shop that had a borescope. I was using a flat electrical snake, they used a round welding rod and it grabbed on.