64 tooth working out well!

Discussion in '4-Stroke Engines' started by 48rob, Oct 22, 2010.

  1. 48rob

    48rob New Member

    I have a bike that came with a 44 tooth sprocket.
    I installed a 4 stroke/Q-matic kit.

    <img src="http://images.yuku.com/image/pjpeg/6c836d854f3b53285d8c450938fa0d22caa210c7.jpg"><P>
    <img src="http://images.yuku.com/image/pjpeg/64726b84d05a35b04073a705249603656eb509a2.jpg"><P>

    The 44 tooth just didn't have any low end power, top speed was 34mph.
    After talking to Lee about it, and discovering his kit was designed for a 56 tooth, I changed it out and gave it a try.
    Worked much better! But, it still seemed to labor too much taking off, and I wanted to have more hill climbing capacity.
    Top speed was 33 mph.

    I picked up a 64 tooth sprocket and had it machined to fit.
    Top speed dropped to just 30 mph.
    It climbs hills much better now!
    <img src="http://images.yuku.com/image/pjpeg/ad416b485e59453d09828452188a2c7d828f27af.jpg"><P>

    I've been riding a 2 stroke for several years now, but really liked the idea of an automatic.
    On my 2 stroke, I overcame the cheap chain tensioner by building my own from a skate wheel.
    On this bike, thanks to tips picked up while reading the board, I threw the tensioner in the trash and learned how to set it up so it isn't needed.

    I'm 180 pounds, and take the bike camping, where there are always a lot of steep hills.
    I'm far more interested in hill climbing ability than a high top speed...though 30mph is about as slow as I want to get.
    Anyone have any hill climbing tips, or mods to reduce pedaling on the really steep ones?
    Though the "hills" here in the midwest aren't much more than bumps compared to mountain states, surely those with real hills have found the right combination of gearing and power?
    (I realize a much bigger engine would do it, but I want to stay legal, or close to it so I won't have problems in different states while out cruising).
    There is a hill here, that if I can conquer without having to pedal, I'll have reached my goal...

    This is the hill;
    <img src="http://upload.wikimedia.org/wikipedia/commons/thumb/1/17/Newport%2C_Indiana_hill_2009.png/600px-Newport%2C_Indiana_hill_2009.png"><P>

    It doesn't look like much, but it is 140' tall, with 1800' from the bottom to the top.
    My bike made it about 2/3rds or so up the hill before needing pedal help.


  2. RdKryton

    RdKryton Active Member

    I have a tip for you. Replace the stock exhaust with a flex pipe and you will see a noticeable difference. Just ask sliverbear. He made the change and is very happy with it. Lee can help you out with that too. BTW nice bike!

    Last edited: Oct 22, 2010
  3. 48rob

    48rob New Member

    Thanks Jim!

    The bike is a GT-2.
    Overall, pretty good right out of the box.

    Thanks for the tip.
    I've got a couple 1" straight through muffler inserts ordered that I want to try.
    The general idea was to lengthen the system a bit, adding the straight through muffler, then bringing the exhaust tip up high and straight back to help reduce the volume and keep the sound from skipping so much, like it does when mounted low.
    I'm torn on the straight pipe idea.
    I want/need more power for hill climbing, yet most of the time those hills are in campgrounds and parks, and bothering all the other people with a loud bike isn't something I want to do.
    Maybe an exhaust cutout valve...hmmm.

  4. RdKryton

    RdKryton Active Member

    A lot of testing was done to determine the correct length for the flex pipe. The big difference in the smooth wall you want to use and the flex pipe is the flex pipe is not perfectly smooth like the pipe. The testing done found that an exact length of flex provided the right mix of back pressure and free flow. I don't remember the length off hand but Lee can answer that question too.
    Good luck
  5. azbill

    azbill Active Member

    nice looking bike :)
    thanks for the write-up/pics ;)
  6. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    The flex pipe was tested on several DYNOs and the best overall powerband was determined. If you choke the system with too much length, or incorrect flow muffler you will reduce the power. It is important to select the correct I.D. and length. The Flex pipe kit uses real automotive pipe and the interior is very smooth compaired other choices.


    Have fun,
  7. 48rob

    48rob New Member

    Hi Quenton,

    Thanks for the tips!
    Is the testing info available on the Internet?

    If the flex pipe system gives the most power, does anyone know how much power the stock pipe/system that comes with it takes away?

    The goal is to have power and be reasonably quiet.
    Actually, very quiet would be better...

    Some people like Harleys and the super loud wake the dead "look at me" pipes, and thats okay for them, but I want to be able to ride my bike in parks and residential neighborhoods without having everyone wish I'd go away.

    Maybe in time, the market will support research for a quiet motorized bike.
    I realize it will cost more, but in the end, it will be good for the hobby, as if we all zoom around irritating our neighbors and public officials, we could discover that they'll use the power we gave them to end OUR enjoyment...

    I really like the automatic, smooth, easy, fun!
    Good job!

  8. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Rob,

    The testing and research on the flex pipe was conducted on several different DYNOs and the data varied greatly. In all cases the flex pipe indicated an increase of 18% or more HP, and the torque peak was also slightly higher. The most important information gathered was the torque curve had relocated it's peak about 600 RPMs lower [slightly more bottom end grunt].

    One motor tested [Honda GXH50] went from 1.90 HP to 2.45 HP with the pipe exchange. The motor had the original "box" type muffler and then the tuned flex pipe.

    The data isn't on the EZM site because EZM didn't conduct the tests [I did] and it certainly won't pass EPA standards. The flex pipe kit isn't actually available from EZM,
    but from Simpson Motorbikes, or myself.

    It is also important to note the design helps reduce the noise as well as supply the necessary back pressure for good overall performance. It is louder than the "box" or kit pipe, but not as loud as you would expect. Nothing like the pipes on a HD or any straight pipe. Most think it has a nice low mellow tone and most like the ease of installation and the increase in power.

    Hope I answered your questions,

    Have fun,
  9. 48rob

    48rob New Member


    Thank you.
    Yes, you've answered my questions very well.
    18 percent is impressive...
    I may contact you to give one a try.
    What do you think about a split system, a cutout that would allow peak performance when desired, and as little noise as possible when needed?
    I suppose the toughest part would be finding a cutout that small...

    On another note, I'd like to change/fine tune the gearing further and would appreciate your thoughts.
    The large sprocket on the rear has me where I want to be for no pedal starts and decent hill climbing, but the front sprocket, clutch and or pulleys are of interest.

    Currently, I can cruise at about 12-15mph before the rpm's drop so much that the clutch disengages.
    I'd like to be able to cruise slightly slower, say around 10mph.
    As it is, at 12-15 because of the required rpm's for the cluch, it sounds/feels like the engine is racing (not slipping, just really fast and loud for the speed).
    Can that be adjusted so the engine doesn't turn so fast at a lower speed?

    Thanks for the help, I appreciate you taking the time to explain all this!

  10. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Rob,

    We have special clutch springs that can lower the engagement speed. How many teeth on the rear sprocket?

    Have fun,
  11. 48rob

    48rob New Member


    The sprocket has 64 teeth.

  12. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Sorry been so busy I didn't take the time to read earlier posts or I wouldn't have asked the sprocket size....DUH

    Special spring will engage clutch sooner. We only have a couple of springs in stock, as it is no longer mfg by Max Torque. The range from idle to "ticking" speed is reduced and may require a different idle setting.

    I think several of our dealers have installed the special spring to allow riding at super low speeds. Maybe they might comment on the differences between the stock EZM clutch and the modified spring version. Not sure but I think AZBill might have tryed the special spring on his stretch and possibly RdKryton tested it on his HF 79 CC build using the Q-Matic drive.

    Have fun,
  13. 48rob

    48rob New Member

    Thank you!

    I understand busy, not to worry, I just appreciate the fact that you and others have any time at all to answer questions.

    I look forward to hearing from the other dealers, sounds like what I'm after!

  14. BiMoPed

    BiMoPed Banned

    Vendor Questions?

    Really? EZM and yourself are different and separate entities?
    You should be in politics LOL

    I really like the flex exhaust too on the 4 stroke motors but a
    correctly designed and sized smooth hard pipe would make a little
    more power than any kind of flex tubing.

    The most "special" feature of the flex pipe that EZM sold / dumped on
    its customers was that it blues and tarnishes very fast as it is not the
    good stainless flex that I would recommend.

    Your Woodland Hills EZ dealer was not very happy with the inferior flex
    pipe that you sold him although it did match the very pretty blue paint
    on his gorgeous Felt EZ build.

    Flex man also mentioned that the ID of the flex pipe was too large to be
    clamped to the 7/8" OD stub from the carp pipe that comes with the EZ kit

    Last edited: Apr 11, 2011
  15. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi BiMoPed,

    As always we are treated to your "negative" comments. Too bad you often don't have a clue to what EZM is testing, designing, producing, or selling, nor do you know my daily routine. We [Mike Simpson & myself] have offered both Standard & Stainless Steel flex pipe kits for some time now, in fact I shipped out both version this morning.

    The vast majority purchase the standard version because of cost, and consider the "bluing" of the pipe "patina". I still have the original version on my test bike and have way over 5000 miles, true it has discolored [like 99% of all motorcycle pipes] near the exhaust manifold, but still maintains the "vintage" look.

    Vintage Whizzers used the standard flex pipe, and managed to live with the results [over 200,000 of them sold]. On certain Whizzer "J" kits the pipe was chrome, and quickly discolored, but no one complained.

    You comment that our Dealer in Woodland Hills, CA was not happy with the pipe.......He didn't mention it to me, and he certainly has the option to purchase the more expensive pipe if he wants.

    I find your negative comments about "dumping" the flex pipe kit, typical coming from you. I also find it interesting, not a single person has asked to "exchange”, "warranty", or "return" any of the several hundred flex pipe kits I have supplied.

    Now I will see just how knowledgeable you really are............Are the standard and the stainless steel version of the pipe the same I.D. size? Do both versions of the pipe test the same? What is the correct I.D. and length for the HS or Honda motor? What is the correct length for the HF 79 CC 4-stroke motor? What is the correct I.D. and length for the Whizzer 138 CC flat head motor?

    Which produces more bottom end torque........ Small I.D. long pipe?.........large I.D. long pipe?.......small I.D. short pipe?........large I.D. short pipe? Does the tip make a difference? Do different style of tips produce different results?

    I do know the answers to all the questions, as we did a major amount of actual testing on both Dynos & "Roller Roads".

    Please treat us to your knowledge, including Dyno, Roller Road, or actual field tests. Can your test bike stay up with the current version of the EZM kit [Do you own a test bike]?

    Do you sell your "tested" version of the Flex Pipe Kit? If so, how much? Please save us from the evil pipe monster.

    Have fun,
  16. KilroyCD

    KilroyCD Active Member

    Yes, this is beginning to sound like the Forbisher of old, carping about things without having all the facts. By the way, I have a non-stainless flex pipe on my bike, and yes, it has the patina. Actually, I like the patina. As to it fitting on the stub, no it will not fit like a piece of (to use an analogy from my line of work) pond tubing onto the tubing adaptor (in other words, a tight fit). The best way to secure it is to use a 1" seat tube clamp, as I did on mine.
    Also, my 49cc HuaSheng with Q-Matic and a 64-tooth sprocket has seen 40mph, so the performance bump is substantial with the correct size and type of flex tubing.

    Attached Files:

    Last edited: Apr 11, 2011
  17. Stan4d

    Stan4d Banned

    For someone who seemed so "new" you seem to be very opinionated about things. I will be here to help you out if you have any questions.
  18. BiMoPed

    BiMoPed Banned

    Thank you!
  19. BiMoPed

    BiMoPed Banned

    Kline's Kustoms 50 Honda with the # ! production Q Matic with a 56 tooth
    sprocket was one of the fastest bikes in our El Dorado park ride even
    compared to the 2 strokes.
    See the pic below of Chris's stainless steel exhaust that has over 1000 miles on it.
    A real GPSed 40 mph.
    Chris's stainless steel flex was much longer than what Quenton says is the correct length and he had a fairly restrictive $8 Briggs lawn mower cannister muffler but his bike was much faster than the Woodland Hills EZ motorbikes
    dealers bike no matter what Flex says.


    OOooppps, a little mistake there LOL
    8600 would be needed to go 40 mph on your gearing setup if you have a
    2" to a 5" pulley in your q matic.
    That is not hard to do as the Huasheng motors love to rev.
    Just don't do it for too long or you may Blow By U your motor.

    Try hitting 40 mph with a 56 tooth and ape hangers. that is a lot harder.

    KilroyCD, your bike looks great.
    Last edited: Apr 12, 2011
  20. KilroyCD

    KilroyCD Active Member

    Thanks for the compliment on the bike. With my bulk I doubt I'd be able to get the bike up to 40mph, but a friend of mine (who is much lighter) did have it to 40 (indicated) briefly. But who says the speedometer is correct? It's a cheapy. I usually cruise at 25-30mph on it. Yesterday another friend who was riding it walked me going up a hill, and I was on my Whizzer. That 64 tooth sprocket (and the flex pipe) had a lot to do with that.
    Last edited: Apr 12, 2011