BMW K bikes (Bricks)

You are not connected. Please login or register

View previous topic View next topic Go down  Message [Page 1 of 1]


1Back to top Go down   Need Baffle Rebuild Suggestions Empty Need Baffle Rebuild Suggestions Wed Oct 07, 2020 9:31 pm

AUBIEBMW

AUBIEBMW
active member
active member
Hello,
I need suggestions on the materials and methods used to rebuild the interior portions of the baffle on my 1985 K100RS.
Thanks,
Jim

    

2Back to top Go down   Need Baffle Rebuild Suggestions Empty Re: Need Baffle Rebuild Suggestions Wed Oct 07, 2020 10:15 pm

Point-Seven-five

Point-Seven-five
Life time member
Life time member
I assume you are talking about your exhaust system. If that is the case, I would just go to eBay and get a used muffler that looks to be in good condition. They are out there for reasonable money since so many bricks are being hacked into cafe or scrambler customs these days.


__________________________________________________
Present:
1994 K75RT
1991 K100RS
1988 K100RS SE

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

3Back to top Go down   Need Baffle Rebuild Suggestions Empty Baffle Rebuild Material Found Mon Nov 02, 2020 7:24 pm

AUBIEBMW

AUBIEBMW
active member
active member
After searching the internet, I realized I may not have been asking the question correctly.  I found stainless muffler rebuild material that I will use to rebuild the baffle sound absorption material.  International Steel Wool sells what they refer to as "Muff Pack Muffler Repacking Kit".  Purchased from Amazon.
Thanks,
Jim

    

4Back to top Go down   Need Baffle Rebuild Suggestions Empty Re: Need Baffle Rebuild Suggestions Tue Nov 03, 2020 12:27 am

Point-Seven-five

Point-Seven-five
Life time member
Life time member
Please post a thread on what you do with lots of photos. I have never heard of repacking a stock exhaust, but the information may come in handy some day.


__________________________________________________
Present:
1994 K75RT
1991 K100RS
1988 K100RS SE

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

5Back to top Go down   Need Baffle Rebuild Suggestions Empty Re: Need Baffle Rebuild Suggestions Tue Nov 03, 2020 7:11 am

jbt

jbt
Gold member
Gold member
The stock exhaust is not an absorption system. The muffler has chambers, with tubes allowing the gas fow to pass to the exit.
Your steel wool will be useless.
If you have an aftermarket exhaust, some use the absorption system.
Steel wool is not a very sustainable material, it is thin, rusts and burns easily.
Glass wool is more resistant.
A good tip is to use different densities of wool to absorb different frequencies. Do not press wool inside the muffler, it has to be loosen to be efficient.

    

6Back to top Go down   Need Baffle Rebuild Suggestions Empty Re: Need Baffle Rebuild Suggestions Tue Nov 03, 2020 8:27 am

Laitch

Laitch
Life time member
Life time member
@jbt wrote:The stock exhaust is not an absorption system. The muffler has chambers, with tubes allowing the gas fow to pass to the exit.
Here's a partial look. Packing it with anything—if it were possible—would restrict flow and affect performance. Go with finding a used one. Is the exhaust is popping during deceleration? 
Need Baffle Rebuild Suggestions Img_2010


__________________________________________________
1995 K75 81,000 miles
Need Baffle Rebuild Suggestions Usa-lo10
    

7Back to top Go down   Need Baffle Rebuild Suggestions Empty Material photos Tue Nov 03, 2020 8:31 pm

AUBIEBMW

AUBIEBMW
active member
active member
Thank you so much for your replies.  I appreciate everyone's patience with my ignorance!!
It is a stock exhaust as far as I can tell. 
Photos show the metallic material full of carbon deposits I am talking about replacing.  Perhaps I should just leave it out and just re-assemble with no material.
Need Baffle Rebuild Suggestions 2Q==
Thanks,
Jim

    

8Back to top Go down   Need Baffle Rebuild Suggestions Empty Without material Tue Nov 03, 2020 8:36 pm

AUBIEBMW

AUBIEBMW
active member
active member
Need Baffle Rebuild Suggestions Z

    

9Back to top Go down   Need Baffle Rebuild Suggestions Empty Complete system Tue Nov 03, 2020 8:38 pm

AUBIEBMW

AUBIEBMW
active member
active member
Need Baffle Rebuild Suggestions 9k=

    

10Back to top Go down   Need Baffle Rebuild Suggestions Empty Re: Need Baffle Rebuild Suggestions Tue Nov 03, 2020 10:57 pm

Point-Seven-five

Point-Seven-five
Life time member
Life time member
Looks like an aftermarket exhaust. Maybe somebody can chime in with who made it. Stock systems are baffled with controlled gas expansion chambers, etc. and don't use packing.

As far as packing what you have, if I couldn't find what the manufacturer recommends, I would probably go with a fairly coarse stainless steel wool. Less risk of corrosion from acids in the exhaust gases, and a higher melting point than regular steel wool. I'd avoid fiberglass as it breaks down and get blown out. And I don't think you want to breathe the microscopic bits that would be floating around when you run the engine in the garage.


__________________________________________________
Present:
1994 K75RT
1991 K100RS
1988 K100RS SE

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

11Back to top Go down   Need Baffle Rebuild Suggestions Empty Re: Need Baffle Rebuild Suggestions Wed Nov 04, 2020 12:37 am

MartinW

MartinW
Life time member
Life time member
Possibly a Mac exhaust.
Regards Martin.


__________________________________________________
K75s Hybrid
    

12Back to top Go down   Need Baffle Rebuild Suggestions Empty Exhaust Wed Nov 04, 2020 1:00 am

daveyson

daveyson
Life time member
Life time member
Maybe even a Kenworth K100 cabover exhaust, looks better.


__________________________________________________
11/1985 bmw k100rt (late model)  Vin. 0090567
 ~120,000 km
    

13Back to top Go down   Need Baffle Rebuild Suggestions Empty Re: Need Baffle Rebuild Suggestions Wed Nov 04, 2020 2:30 am

jbt

jbt
Gold member
Gold member
The black coating (and the fact that there still be a black coating!) let me think this is a Luftmeister exhaust.
The shape of the rear cylinder tube is typical.

    

14Back to top Go down   Need Baffle Rebuild Suggestions Empty Re: Need Baffle Rebuild Suggestions Wed Nov 04, 2020 5:08 am

Dai

Dai
Life time member
Life time member
Find a good s/h standard exhaust. It might not be a pretty as a round exhaust system but tests waybackwhen showed that BMW had got it completely right and none of the aftermarket manufacturers were able to extract any more power out of the engine. It also has the advantage of being stainless steel, which means they're relatively cheap because they don't fall to pieces easily.


__________________________________________________
1983 K100 upgraded to K100RS spec, 1987 K100RT
Others...
1978 Moto Guzzi 850-T3, 1979 Moto Guzzi 850-T3 California,1993 Moto Guzzi 1100ie California
2020 Royal Enfield Bullet 500
    

15Back to top Go down   Need Baffle Rebuild Suggestions Empty Re: Need Baffle Rebuild Suggestions Wed Nov 04, 2020 7:24 pm

AUBIEBMW

AUBIEBMW
active member
active member
Excellent comments.  I searched on Luftmeister exhaust and found what looks exactly like it. 

There are other comments such as the following that lead me to believe I am headed in the right direction with the stainless steel wool.  Worst case I can remove again and just try without.

"Luftys sound great if you can keep the can packed, I never could and got to like it with no packing"

and

"Google muffler packing.  Amazon, most bike shops sell it.  Usually fiberglass but I've seen stainless steel wool that may last longer."

Does anyone have suggestions on surface repairs on the header tubes, and paint or jet-hot once repaired?
Need Baffle Rebuild Suggestions 9k=

    

16Back to top Go down   Need Baffle Rebuild Suggestions Empty Re: Need Baffle Rebuild Suggestions Wed Nov 04, 2020 9:29 pm

Point-Seven-five

Point-Seven-five
Life time member
Life time member
The hipsters who build cafe bikes use muffler wrap. I think it's supposed to make more power or something. While an acquired taste, it really doesn't look too bad when done neatly.

Downside as I see it is that your pipes do not appear to be stainless and wrap would probably accelerate the corrosion.


__________________________________________________
Present:
1994 K75RT
1991 K100RS
1988 K100RS SE

Past:
1994 BMW K75S
1992 BMW K100RS
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

17Back to top Go down   Need Baffle Rebuild Suggestions Empty Re: Need Baffle Rebuild Suggestions Wed Nov 04, 2020 10:21 pm

MartinW

MartinW
Life time member
Life time member
Try using heatproof ceramic spray paint or get it professionally done.
Regards Martin.


__________________________________________________
K75s Hybrid
    

18Back to top Go down   Need Baffle Rebuild Suggestions Empty Re: Need Baffle Rebuild Suggestions Thu Nov 05, 2020 4:44 am

jbt

jbt
Gold member
Gold member
@Point-Seven-five wrote:The hipsters who build cafe bikes use muffler wrap.  I think it's supposed to make more power or something. 
It's bullshit.
It used to be necessary on lateral old car engines, where some issues appeared due to the poor compression ratio and the unadapted shape of the combustion chamber and exhaust. Packing the exhaust helped to reduce the condensation phenomenon when the gas meet a low pressure envidonment outside the engine.
Then, with engine more performant, it was useful under closed bonnets on hot rods, the exhaust was prone to create heat managment problems with the fuel.
Today, apart on very hi performance engines (drag racing), and particularly on motorcycles with open air engines, it's useless and may even be counter productive.
It's a pure fashion victim gimmick.

    

View previous topic View next topic Back to top  Message [Page 1 of 1]

Permissions in this forum:
You cannot reply to topics in this forum