New HS motor very rough idle

Discussion in '4-Stroke Engines' started by mmachine, Jul 22, 2009.

  1. mmachine

    mmachine Member

    Hey there, working on my 1st build with a HS 4 stroke. First off I'll let you know I live at altitude here in Denver the mile high city. The engine starts up easily enough but didn't idle out of the box without adjusting the idle screw. Not sure if that's normal or not.

    When at idle, it surges, can't supply sound but will try typing it out.

    dit dit dit rrrrrrrr dit dit rrrrrr dit rrrrrrrrrr dit dit dit dit rrrrrr make sense?

    Anyway, noticed another adjustment screw which I've fiddled with but don't know what I'm doing. Does that adjust air or fuel?

    Ready for suggestions from folks that run this engine and hopefully at altitude.

  2. Mountainman

    Mountainman Active Member

    well usually if carbs have two screws
    one is for gas and the other is for air intake
    may be too late for this
    when I am messing with anyTHING other than an idle screw I count any turns in or out
    makes it easy to come back to where we were
    even if you have messed THINGS up a little
    you should be able to dial it in -- with a little playing around
    slight adjustments are best for a nube
    remembering where you started

  3. mmachine

    mmachine Member

    Have 2 screws, one for idle only, the other is what the inquiry is about. I take you aren't running this motor?

    Appreciate the quick reply though.
  4. Mountainman

    Mountainman Active Member

    correct not running that one
    have worked on various types over years
    so you adjusted the air intake screw and not sure where you started ??
    if so air screw can be adjusted while running
    if you can get it running

    if we are not sure where to start
    I would screw screw all the way in and come out 1 1/2 turns
    go from there

    or someone on site with same engine can check and see how far out screw is ??
    contact a couple of guys here on site with same -- these ones will help you

  5. MotoMagz

    MotoMagz Member

    This was posted by Quenton Gunther:carburetor


    In order to adjust the carburetor it is necessary to warm the motor up first. The motor should have at least 5 minutes running time before any adjustments are made.

    On the left side of the carburetor near the front is the idle mixture screw.

    On the EZM motor the idle mixture screw is a fuel adjustment, not an air adjustment.

    Simply adjust the screw for maximum idle, and then turn the screw approx 1/16" counter-clockwise [slightly rich].

    Check the throttle response, and adjust the mixture if there is a hesitation. Turn screw clockwise if it "bulks" and then catches on [rich], or adjust screw counter-clockwise if it accelerates and then drops off quickly [lean]. It worked for me!! MotoMagz
  6. mmachine

    mmachine Member

    Thanks, I'll give that a try. I did a lot of searches but misspelled carburetor.
  7. mmachine

    mmachine Member

    is that a thumbs down?

    What's that red thing top left above my previous post?

    Is that a thumbs down? Something I said?

    Please explain.
  8. MotoMagz

    MotoMagz Member

    Hey not from me!! You must of hit one of the icon buttons at the bottom of the post page.MotoMagz
  9. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    what gearbox are you using?
    did you buy a kit? from who?
    how do you like it?

  10. mmachine

    mmachine Member

    LOL, no not you, you gave me a precise answer that I can't wait to try out. I must have hit a button unknowingly will go forward with caution.

    What kit/gearbox?

    Bought from BoyGoFast on ebay which I won't do again as it's not the quality I had in mind. Haven't finished bike one yet and working on #2. Always waiting on parts of some sort and must keep moving. Will be using the EZM kit because the drive system is what I'm looking for.

    Realized it's better to go with quality from the beginning if I want to be happy with the finished product. If you go cheap you'll end up spending $ to make it right latter anyway so doing it right in the beginning saves time, money and agrevation.

    I'll post pics when things move farther along.
    Last edited: Jul 23, 2009
  11. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    so you have the infamous J.L. Hoot gearbox or similar

    you have my sympathies and there may be one or two people
    who got theirs to run for any length of time at an acceptable level

    i have one as a curiousity but would never be foolish enough to
    actually try and use one on a build

    you could buy a Grubee gearbox to salvage your kit for about $120
  12. mmachine

    mmachine Member

    Oh so that's the dreaded Hoot gearbox I've read about. Hoping for a healing
    with the EZM.

    Do you know what "hope" is? It's the rope you hang yourself with when hopes
    are dashed.:ack2:
  13. 4-Stroke gearbox

    Hi I am familiar with most of the gearboxes available, if you put up a pic, I can ID it for you.

  14. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

  15. Gearbox ID=JL Hoot type

    Hi IF you have the one in the pics, there are about 3 variations of it. The first type was what I had, it ran about 50 miles. The second and third types can last a while. I do have plenty of parts for these, tho I do not know who else might.

    Go ahead and build it, ride it, and enjoy it, and if it breaks down, try to fix it and keep going!

    As of yet, the friendly people at Brand X are not selling gearboxes, just kits, so Ride On!

  16. mmachine

    mmachine Member

    mine's different

    The Boy's pics are showing a different unit than what I have. I get a pic up later today. What I like the least about mine is it's only 3 - 1 reduction which isn't nearly enough.
  17. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    is BoyGoFast still selling what you bought?

    if so please put up a link to a current or finished auction

    is it chain drive inside?
  18. mmachine

    mmachine Member

    Don't have link to auction, it's been about 6 weeks.

    Yes there is a chain inside and 3 - 1 reduction.

    After couple hours of run in, tweaking the fuel screw and smoothing out bent wheel and sprocket wobble issues it's running well.

    Only need about 5 mph of speed then give it the gas to engage clutch, then it
    takes off on it's own just fine. Opened it up and there's minimal dust from
    clutch so I know it's engaging and not slipping.

    And now I'll attempt to attach pics.

    Attached Files:

  19. MotorBicycleRacing

    MotorBicycleRacing Well-Known Member

    thanks a lot for the photos
    its some kind of pocket bike transmission
    & thats the chain one I have seen before

    please keep us posted on how it works for you

    how is the noise from the transmission?

    what kind of speeds are you getting?

    a pic with the cover off would be much appreciated

    how many teeth on the front and rear sprockets?

    what is the final ratio of your chain sprockets?

    sorry bout all the questions

    Thank you
    Last edited: Jul 26, 2009
  20. mmachine

    mmachine Member

    how is the noise from the transmission? none that I'm aware of

    what kind of speeds are you getting? dunno, tried to get a speedo working today but it conks out as soon as I stop peddalling and go under power

    a pic with the cover off would be much appreciated I'll work on that

    how many teeth on the front and rear sprockets? 9 and 27(inside drive box)

    what is the final ratio of your chain sprockets?12 - 1

    sorry bout all the questions no prob, I've learned everything on this site by reading questions and answers, great site