Spark Arrestor Solutions

Discussion in 'Trials' started by motobene, May 23, 2017.

  1. Huzband

    Huzband Team Dirt

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    4 strokes are required to have header wrap to ride our property, but it's not required to run FTR races. Go figure.
    #21
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  2. motobene

    motobene Motoing for 46 years

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    Not my welds. That's the purchased part. Mine will be solid machined.
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  3. motobene

    motobene Motoing for 46 years

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    USFS requirements are for the screen mesh to be 0.023" or less and twice the area of the smallest restriction of the muffler. Also the unit must be removable so the arrestor can be cleaned.

    On top of that are "approved" or tested arrestor. For practical purposes almost always, the fact that you have an arrestor is what matters.
    #23
  4. ridenm

    ridenm Long timer

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    Yes, if a ranger gives you a hard time about a sparky that's not listed but still meets the intent, either he's having a bad day or you pissed him off somehow.
    #24
  5. motomaster132003

    motomaster132003 Adventurer

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    20170523_163347_1495583541126_resized.jpg 20170523_164339_1495583542215_resized.jpg


    The Spanish Fly Spark Arrestor definitely doesn't restrict air flow. It slides over the stock exhaust tube and replaces the rubber piece inside the end cap. I decide to go this route because it is less expensive than buying the end piece and spark arrestor. It also doesn't stick out like the other option, so you have less of a chance of breaking it off.
    #25
  6. Limbman

    Limbman Adventurer

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    I found and looked at the Spanish fly option but my friend Motobene hooked me up with the pictured option above. My concern with the slip in option was two fold. One it could slip out somewhere along the trail and if not it could be difficult to slide in and out to clean. How tight does it fit and how difficult to slide in and out?
    #26
  7. lineaway

    lineaway Long timer

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    It goes in easy, but coming out is no fun. I took mine out when I was going to the Nationals and they were not required. I will not be removing it again.
    #27
  8. motobene

    motobene Motoing for 46 years

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    The slide-in Spanish Fly solution is pretty cool.

    It looks to me like the plastic end cap had to be bored out for the outside diameter of the arrestor. Was that done? If true then it's not a reversible mod.

    The vast majority of time I have no need for a spark arrestor. Only when I go west into NM, CO, etc is one required, though never once has anyone checked that I have one.

    I've never heard of a trials bike starting a fire. I've never seen a glowing chunk of anything come out of the muffler. I've got a ranch that sometimes gets really dry, and if riding trials bikes without spark arrestors were a problem it seems something would have happened by now.

    Someone somewhere else says we have to have them, so I do. They are irrelevant in my region, however.

    Gilbert Pinchot's new Forest Service found its reason to be and celebrated cause (fire suppression) after the Big Burn of 1912 provided the public and political support. Spark arrestors are logical offshoot. Only you can prevent forest fires! -with your puny spark arrestor!

    There are no 'approved' spark arrestors for campfires, smokers, chain danglers, and trains... or catalytic converters.
    #28
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  9. motomaster132003

    motomaster132003 Adventurer

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    No mods required for the Spanish Fly. Its about a 5 min install. Remove the end cap, remove the rubber piece, slide the Spanish Fly into the end cap, reinstall the end cap with the Spanish Fly by sliding the Spanish Fly over the stock exhaust tubing.
    #29
  10. UstaKood

    UstaKood Adventurer

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    Some years ago, we were out in a far corner of a local lake ( middle of winter ) having a good ol' time Ice Racing . The CO walked out ( about a 1/4 mile ) looking for the 2 that were on the 3 wheeler he observed riding without a helmet . ( They had just got there with a cooler ) he went to my bike ( TT 500 ) pulled out a pen and stuck it in the end of the pipe ....

    " This motorcycle does not have a spark arrestor . I'll give you 2 options . Pack it up or I start writing tickets " !

    Ahh..." Yes Sir "
    #30
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  11. lineaway

    lineaway Long timer

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    He was just trying to save the ice from melting.:jack
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  12. motobene

    motobene Motoing for 46 years

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    I am scratching the hairless noggin.

    I look at my Shercos and see solid plastic end cap all the way to the outer edge of the thin steel exit tube. In your pic I see wide blue anodized aluminum peeking out of the end cap. There's no rubber that I can see.

    I've never had one of these caps off.
    #32
  13. motomaster132003

    motomaster132003 Adventurer

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    20170524_060208_resized[41772].jpg

    This is what the rubber piece looks like in the end cap. It slides over the exhaust tubing and prevents it from moving around inside of the end cap. The Spanish Fly takes the place of this piece.
    #33
  14. Brewtus

    Brewtus Buffoonery, Inc.

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    Yes, we have.

    Welcome to my argument against these stupid things. :csm
    #34
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  15. motobene

    motobene Motoing for 46 years

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    I GET IT NOW! The raised bit I see around the muffler end cap at the steel exit pipe is rubber, not plastic!

    That's a slick solution for those regions always requiring an arrestor.
    #35
  16. Limbman

    Limbman Adventurer

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    It is a clean look. The only issue I see is the ease of taking it out for cleaning of the scum that is blocking flow?
    #36
  17. ridenm

    ridenm Long timer

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    One year at Sipapu during drought season the Forest Service was hypersensitive and we checked to placate them and keep our special use permit secure.
    FS and BLM LEOs can check at any time, though I've never seen it happen.
    #37
  18. lineaway

    lineaway Long timer

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    Every year the Presidemt of our club greets the local ranger dressed in his best and woth promises of good behavior and all the cold ones he can drink.

    Attached Files:

    #38
  19. motobene

    motobene Motoing for 46 years

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    Wise indeed to be cooperative and friendly with all the king's men!
    #39
  20. motobene

    motobene Motoing for 46 years

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    I started machining my own mount for my personal bike's surface-mount Sparky at outside diameter 32.2mm.

    It took way to long to part a slug of 2-3/8" 7075 aluminum on the Kalamazoo horizontal bandsaw. Definitely a one-off effort.

    It worked very well at the Sipapu 2-day event.
    #40