#Airhead - I dropped a muffler and kept riding...

Discussion in 'Airheads' started by baldwithglasses, Dec 22, 2011.

  1. baldwithglasses

    baldwithglasses Godspeed, Robert

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    Hell naw, it's Kennesaw!
    How much damage if any might I cause my motor if I keep riding for an hour and a half after dropping my muffler?

    Riding from Atlanta to Blountsville on I-20(!), my R65 suddenly got very loud. I looked down, saw a lack of left-hand muffler just aft of my footpegs, and kept riding.

    Now what?
    #1
  2. fishkens

    fishkens Long timer

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    Remove the other one?



    But cereally, I'm sure the motor is fine. Start shopping for a replacement muffler.
    #2
  3. mykill

    mykill odd

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    It'll be fine, I would avoid flogging it until you get a replacement. I have a set with some good patina if you are in need.
    #3
  4. baldwithglasses

    baldwithglasses Godspeed, Robert

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    Hell naw, it's Kennesaw!
    That's kind of what I figured, but I did want to check in with the Airhead cognoscenti for some feedback.

    Because my bike's a ratty Frankenbike, is it possible for me to kludge on something like a tractor muffler from a vehicle of similar displacement?
    #4
  5. Airhead Wrangler

    Airhead Wrangler Long timer

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    You mean you didn't stop to pick it up?
    #5
  6. baldwithglasses

    baldwithglasses Godspeed, Robert

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    Hell naw, it's Kennesaw!
    No. It was raining, it was windy, it was cold, my manly bits were pulling a cold turtle, and it was in a narrowed construction zone.
    #6
  7. hardwaregrrl

    hardwaregrrl ignore list

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    Doode!!!!!

    <a href="http://hardwaregrrl.smugmug.com/Other/misc/16038929_6qzPj6#1643853226_pfLsfHh-A-LB" title="Photo & Video Sharing by SmugMug"><img src="http://hardwaregrrl.smugmug.com/Other/misc/i-pfLsfHh/0/L/images-L.jpg" title="Photo & Video Sharing by SmugMug" alt="Photo & Video Sharing by SmugMug"></a>
    #7
  8. baldwithglasses

    baldwithglasses Godspeed, Robert

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    Hell naw, it's Kennesaw!
    Fucking I-20.
    #8
  9. Stagehand

    Stagehand Imperfectionist

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    Yes, although nothing will provide that awesome unbelievable performance that the R65 stock muffler will put out.
    #9
  10. supershaft

    supershaft because I can

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    Hilarious! I have seen bikes drop a torpedo before. I have seen bikes shoot out a muffler core too. Not good when you are right behind them! :lol3

    Locktite? I would start with tightening things down! :D Seriously though, regularly reach down and grab your mufflers by the end and try to twist them. If you can, your front clamp is loose. Riding with the front clamp loose will get your pricy mufflers cracked way before their time. When it won't twist, jerk it around to make sure the mount bolts are tight. If they were tightened down right to start with, they don't come loose but it doesn't hurt to check while you are there.

    I find bikes with loose front clamps all the time. It is the start of expensive trouble so why go there?
    #10
  11. mykill

    mykill odd

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    It is not a sin to have a ratty frankenbike, but it is a sin to have a badly running ratty frankenbike. Do you really want to mess around with jetiing and flat spots?
    #11
  12. baldwithglasses

    baldwithglasses Godspeed, Robert

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    Hell naw, it's Kennesaw!
    Then send on those patina'd muffs, sir. PM pending.
    #12
  13. Hawk Medicine

    Hawk Medicine Coyote's Brother

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    Hmmm...

    I lost the baffel in one of my Hoske mufflers and it ended up causing me to burn an exhaust valve but it still ran for about 1K miles.

    You'll be alright!
    #13
  14. xavier296

    xavier296 Alaska n'Back

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    sok,

    why would the loss of the baffle cause a burned exhaust valve? Jetting? I replaced my Hoskes with some shorty reverse cones, and they are straight through.
    #14
  15. Hawk Medicine

    Hawk Medicine Coyote's Brother

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    Youre running straight thru mufflers with the stock jetting? I sure wish I could do that. It would save me a lot of time and head scratching! :lol3
    #15
  16. Airhead Wrangler

    Airhead Wrangler Long timer

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    I fired the core out the back of a jawa 350 twin. It made one unholy smokey racket. I walked back and picked it up and jammed it back into the tube and rigged it with bailing wire. It stayed together long enough for me to lunch the transmission a couple weeks later. I ended up selling the bike for parts at a livestock bazar in eastern Kyrgyzstan. True story.
    #16
  17. dorkpunch

    dorkpunch Oops...

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    I had a Honda Trail 70 that had exactly 2 inches of exhaust pipe. It ran that way for years, and years, and years, and , well you get the picture. Always heard that running an engine like that would ruin the engine because the exhaust valve would be cooler than its supposed to be. I eventually tied a muffler on to it (literally) and its still going strong...

    Pic from after the muffler instal- maybe 10 years after the original fell of.

    [​IMG]
    #17
  18. Airhead Wrangler

    Airhead Wrangler Long timer

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    I'd say that half of all trail 70s still running today are used almost exclusively for popping wheelies in one's own yard and other assorted hooliganery.

    [​IMG]
    #18
  19. dorkpunch

    dorkpunch Oops...

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    It was used a lot for that, fer sure. :evil

    Before it was mine, it belonged to my brothers friend, who rode it from town 2 miles out to the dirtbike track, then around the track. He also put TWO other people on it with him, then the 3 of them would take turns riding around the track. :lol3
    #19
  20. baldwithglasses

    baldwithglasses Godspeed, Robert

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    Hell naw, it's Kennesaw!
    I found some instruction here:

    http://www.practicalmachinist.com/vb/general/lawn-mower-muffler-design-225238/

    "If you want to make a muffler and have access to some fairly basic sheet metal working tools, the job is easy. Take some 12ga or 14 ga stock and roll a cylinder that is something on the order of 6" long by 3" - 4" in diameter. Bigger is better. Using a hole saw of suitable diameter, cut a couple of ends, using slightly heavier stock, maybe 10 ga. Cut a rectangular piece of flat stock so that it will bisect the cylinder into two equally sized half-cylinders. Using a small drill, about 1/4" or less, drill a series of holes in one half of the rectangle so that you have a solid square portion and a swiss cheese square portion. (I' m trying to be illustrative here.) The combined area of the holes should approximate the cross section of the NPT pipe inlet. Now, using another hole saw, cut suitably sized holes in one end round to accommodate your desired pipe fittings. These holes should be offset so that when assembled the inlet hole will be on one side of the rectangular divider and the outlet will be on another. It may be a good idea to extend the inlet pipe into the muffler a bit with a bracket to the body for strength. The swiss cheese portion of the divider should be away from the inlet and outlet.

    Weld everything together and you are ready to go. Remember, muffler's volume, the quieter the result. Also, the more convolutions you add internally, the quieter the result. Circular drilled baffles or a series of alternating three quarter baffles will work at least as well as what I described and make it easy to have the inlet on one end and the outlet on the other but may be harder to assemble. If the volume of the muffler is sufficient, it may make sense to downsize the outlet pipe by one size.

    The non-technical reason engine exhaust is noisy is because a volume of compressed air is released rapidly, creating a big POP, sort of like popping a balloon. What you want to do is to break that percussive emission into a steady, smooth flow of air. Mufflers work primarily by having that force front of air bump into things until it loses some of its energy and flows out smoothly.

    You can calculate some dimensions to make an expansion chamber muffler if you really have nothing to do. The volume of the muffler should be at least the volume of the engine's displacement, and the outlet pipe diameter should be such that one volume of air will flow through the pipe at your desired back pressure in the time it takes the engine running at full speed to complete one cycle (two revolutions of the crank for a four cycle engine). I'm sure there is much more to it than this but I just want to convey a general idea. "​
    #20