Re: Vibration???

Discussion in 'General Questions' started by Gary Stout, Jul 17, 2010.

  1. Gary Stout

    Gary Stout New Member

    Is the 2 cycle motors known for a lot of vibration? I have some rubber pads between the mounts and the frame, but anything over about 15mph is just about unbearable. I have ordered a rear mount 4 cycle and hoping that it will be balanced better, since I am assuming those have a flywheel.

    I have got the bug and love to ride this thing...I just need to fine tune things and make it as smooth as possible. I did manage to ride about 40 miles today, but the vibration makes my hands numb.

    Any thoughts?


  2. Al.Fisherman

    Al.Fisherman Active Member

    Last edited: Jul 17, 2010
  3. motorpsycho

    motorpsycho Active Member

    every engine will have vibrations, especially a single cylinder. it all depends on the moutning method. rubber pads between the frame and the mounts will not do very much.
    if you want to eliminate any engine vibrations, you will need to make your own mount consisting of a steel mount, with a thick rubber doughnut, to another steel mount, with a nut & bolt holding it all together, sandwiching the rubber doughnut between the steel.
    check out a harley davidson rubber motor mount and you'll see what a i mean.
  4. loquin

    loquin Active Member

    Also, knobby tires on pavement can be VERY prone to vibration. If you aren't going off-road, slicks provide the smoothest ride and best traction. Tread isn't needed on pavement for bike tires - it actually reduces traction under all conditions except (possibly) wet snow.
  5. Gary Stout

    Gary Stout New Member

    I am using a Hybrid bike and the tire tread is not aggressive at all. If I am coasting down a hill and pull the clutch in and reduce engine rpm's, the vibration is minimal, so it seems like it is all coming from the engine itself. This is an aluminum frame bike and I am using some of the large tube adapters, so mounting is probably not ideal as it would be on a steel frame with a "normal" V frame.

    See picture.....

    Attached Files:

  6. Gary Stout

    Gary Stout New Member

    Has anyone here used a 4 cycle engine and know if they are better balanced? I thought perhaps since they have a large flywheel, maybe the balancing is better. I guess there are probably pros and cons to both types. I do like the fact that if I am out on a long ride and need some gas, I can fill up without having to mix in the oil, but also need to keep a closer eye on the crankcase oil.

  7. azbill

    azbill Active Member

    on my bike,,,4stroke, HS 142F powered EZM kit,,,
    while idling, I can put a coffee cup on my seat without it spilling ;)

    I wouldn't try that when I was using a happy time, I enjoy my coffee too much LOL :)
  8. Gary Stout

    Gary Stout New Member

    Thanks for the info! I am looking forward to that kind of performance :D I have been bit by the motorized bike bug and sure don't want to give up on it now. I have been happy with the power and hill climbing abilities of the 66cc Grubee Skyhawk GT5 and a 48 tooth rear sprocket. This thing will pull some pretty decent hills with no effort at all. Hoping the 49cc 4 cycle will do well in that regard as well. Top speed seems to be up in the 40's....way to fast for the narrow tires on the hybrid. About 20mph seems like a nice cruising speed on this particular bike.

    Thanks again for your comments,
  9. Whizzerd

    Whizzerd Member

    Meticulous fitting of the HT to your frame is the key. Most here advise against rubber mount pads as it allows the engine to move creating broken mounting bolts, etc.. AZBill has several thousand miles on his EZM equipped bike as well as Quentin, J.B. and others. I've gone to 4strokes 'cause I like to actually SEE out my rear view mirrors! Some of that vibration is caused by that xtra chain. I've been using BMP Friction Drives and 4 strokes lately. Try the 4 stroke, you'll like it!
  10. Gary Stout

    Gary Stout New Member

    Thanks....the 4 stroke arrived this week and going to start installation today. Can't hardly wait to give it a try. Installation should be fairly quick since I already have the sprocket mounted from the 2 cycle install.

  11. Fulltimer

    Fulltimer Member

    Good luck and be sure to post some pics!

  12. beentryin

    beentryin Member

    i used the rubber in the fins and cardbard on the clutch and wow!! does it make a diffrence
  13. Gary Stout

    Gary Stout New Member

    WOW!!! I put the 4 cycle on over the weekend and I will NEVER use another 2 cycle after seeing how smooth this 4 cycle is.....also quieter. With the 2 cycle, I had major vibration over about 15mph. The 4 cycle cruises very smooth at 30mph, which seems to be top end on my setup.... 11 tooth on the engine and 48 tooth on the wheel.
    The centrifugal clutch is kinda nice also and gets rid of one lever on the handlebars.
    I liked the way the 2 cycle looked on the bike and the weight was distributed much more evenly, but I am much more happy with the ride on the 4 cycle.

    Seems like the 4 cycle uses a little more fuel than the 2 cycle did. I haven't rode it enough yet to see exactly how many miles I am getting per tank. Also not sure how big the tank is, at this point. It looks smaller than a 1/2 gallon, which would explain why it seems to need fuel more often.

    The attached pictures show the 2 cycle version and the new 4 cycle version.


    Attached Files:

  14. Whizzerd

    Whizzerd Member

    Your mpg's should actually nearly double Gary. I'm very happy for you. Makes it just that much more fun!
  15. Gary Stout

    Gary Stout New Member

    I may need to do some carburetor adjusting then. So you think I should get better mpg's with the 4 cycle than the 2 cycle?

    I am not sure how much the tank holds that came with the 4 cycle. It doesn't look like a half gallon to me, but I haven't verified how much it does hold. If it is less than a 1/2 gallon, then that would explain why it seems like it is using more. The cap on the tank has 1/25 on it, but I have no clue what that is indicating.

  16. Whizzerd

    Whizzerd Member

    My 66 cc HT got 80-90 mpg on break-in fuel. My HuaShang got 145 mpg when new. Generally, those figures should improve as the engine "loosens up" a bit. Doesn't matter really. I still prefer the 4 stroke.
  17. Gary Stout

    Gary Stout New Member

    Does anyone know off hand what the capacity is of the Huasheng tank? I have the rear mount version so it has the plastic tank with the closed loop fuel system. The V mount version uses the standard tear drop tank.