Hi-flow Muffler Insert:

Discussion in 'Whizzer Motorized Bicycles' started by Hal the Elder, Nov 12, 2008.

  1. Hal the Elder

    Hal the Elder Member


    I was advised to install one of these HI-FLOWS in place of the stock muffler insert, to complement my intake modification.

    Kilroy said it gives a "Throatier" sound. Well, that's OK as long as it's not too much louder!


    How much should I send you for a new Hi-Flow and the shipping charge to California, 92308?

    HAL (The Newbie Elder)
    Last edited: Nov 12, 2008

  2. RdKryton

    RdKryton Active Member

    Last edited: Nov 12, 2008
  3. Hal the Elder

    Hal the Elder Member

    Hey Jim:

    The opening in my muffler insert is about 16mm in diameter. (5/8")

    A 1" opening (25.4mm) will provide about 2-1/2 times the exhaust flow.

    (Using the ratio of the areas between a 25.4mm opening and a 16mm opening)

    Last edited: Nov 12, 2008
  4. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Hal,
    Information central here to help.
    Of course there have been a few changes to the muffler insert over the last several years. The early NE5s used a smaller pipe [same as the WC-1] and some had the WC-1 type insert. Around this time I worked with a muffler expert named Tom Hand, and we supplied a really nice insert [either in black or chrome] and used American labor [welding, machining, painting or chrome process], and quickly sold out [except for the one I sent to a company in TX]. Later the NE pipe was enlarged, and a different insert was supplied, and later a much better version apeared in the pipe [very similar to the earlier Tom Hand design without the stinger]. Here are the facts about the inserts, the first inserts were very restrictive, and many drilled holes in them to help the flow, the second edition was almost beyond help, and the last edition was pretty good [but all weren't the same]. The second edition simply had a flat plate on each end with a large open chamber in the middle, which caused massive turbulance. When I re-worked a new motor for someone at the TX company [you know, hopped it up], I couldn't figure why the motor ran so poorly during initial testing, and when I installed one of the Tom Hand inserts, it became instantly clear why. It is easy to tell which is which, and easy to modify the later edition to work better. The best of the bunch [not including the rare Tom Hand edition] is the latest version, and is easy to detect. If the center pipe is attached to the large [approx. 1"] hole at each end, it is a "keeper". However it is very important that the forward end [towards the front of the bike] have a completely level area to allow the exhaust to flow & pulse correctly. Every once in a while I will get one that is welded flush and doesn't require my "touch", but the majority need the tube cut off flush to avoid trapping the exhaust between the center pipe and the outer edge of the insert. And of course the modified area requires a little heat paint to avoid rusting. If you find your bike has the insert with the smaller hole [approx. 7/8"] and no center tube to guide the exhaust flow, just hang it on the wall, make a lamp out of it, deposit it in file 13, or whatever and replace it with the better version. The earlier small WC-1 version can be helped by drilling a lot of 1/4" holes everywhere, but it isn't worth all the labor for the small increase in exhaust flow. Most dealers can supply the better version for approx. $20.00 plus shipping, and of course I have lots of them somewhere in my parts room, including a few of the chrome Tom Hand versions]. Oh, just a few final comments, the sound is great. It produces a really deep tone, and usually enhances the performance in the middle of the power band, and the worst loss was at WOT on Kenny Thomas's "Roller Road" at 1 MPH less [slowed from 68 MPH to 67 MPH].
    Have fun,
  5. Hal the Elder

    Hal the Elder Member

    Hey Quenton:

    Read my reply to Jim's post:

    The hole in my insert's rear baffle is 5/8"...NOT 7/8"!

    This is even smaller than the opening I made in my intake restrictor, which is 3/4"!

  6. RdKryton

    RdKryton Active Member

    You do not have the Hi-Flow insert. You should get one. You'll love the sound and it helps it run better too.

  7. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Hal, Give Oscar a break, let him "exhale" better, since you let him "inhale" better. Check with Mike Simpson or Bill Green, I think they are a lot closer to you and could save you a few bucks on shipping. If they don't have them in stock let me know.
    Have fun,
  8. KilroyCD

    KilroyCD Active Member

    Hal, you'll definitely love the sound with the Hi-Flow. Although it should help your performance, it's worth investment for the sound quality alone.
  9. Hal the Elder

    Hal the Elder Member

    Gentlemen,you've Got Me Sold!

    It seems incongruous that I allowed Oscar to INHALE deeply, without allowing him to EXHALE deeply, so I'll order a Hi-Flow Muffler Insert right away!

    Who wants to sell me one and where do I send my money to?

  10. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Hal, If no one offers to take your money and send the special insert, email me your shipping address at quincy163@yahoo.com and I will see that Oscar can exhale properly.

    have fun,
  11. Stock Insert

    Hi Hal, I also have them, I'm in Sacramento CA.

  12. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Hal, Looks like help is on the way. I think Mike is closer to you and can save a little on shipping. Just ask him to make sure the front side is level with the mounting plate, if not ask him the cut it flush for you [it is worth a few extra $$].

    have fun,