2 to 4 Stroke

Discussion in '4-Stroke Engines' started by StoreKeeper, Jan 11, 2011.

  1. StoreKeeper

    StoreKeeper Member


    I just bought this kit to convert my 2 stroke to 4 stroke.

    I have it installed and I found I still have to pedal to get going.

    Do i need a bigger sprocket in the rear ,I have 44 now.

    Any other information you can give me on the 4 stroke bike would be appreciated.

    Rx Bruce

  2. professor

    professor Active Member

    You can do the bigger rear sprocket but you will loose top speed.
  3. ibdennyak

    ibdennyak Guest

    Looks like you have a 20-1 ratio which is pretty close to optimal for a single speed. With a single speed, pedalling to get started isn't a bad idea at all. What kind of top speed do you have with the 44?
  4. StoreKeeper

    StoreKeeper Member

    Went 1/4 mile then it Broke:confused:

    Engine runs and belt assy turns but no turn the small gear that on the chain?
  5. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Storekeeper,

    Your motor has the 4G drive, and has had a few issues with the freewheel. Some versions had the freewheel as the final chain output, whereas others have the larger internal freewheel. Sounds like the freewheel stopped working correctly.

    The version you have indicates the front primary is 5 X 1, and the secondary is 4 X 1, making the total 20 X 1. I am surprized you need to pedal assist with such a radical ratio. If the numbers are correct, be VERY careful, as the motor without a load can easily exceed the redline and become scrap metal. At 20 X 1 the motor will hit the redline [7800 RPMs] at 30 MPH.
    I also notice the site you indicated the motor has 2.5 HP, sorry but I have never seen the HS rated so high, wonder if the numbers are a little optimistic.

    Good luck,
  6. StoreKeeper

    StoreKeeper Member

    I have the 44 tooth rear sprocket and Helo Bikes recommends 56 teeth since I weight 225 and go up hilly street at times.

    The 44 seems to slip the clutch when I start from a stop and going up the hilly streets.

    What are your guys thoughts?

    Thanks in advance

  7. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Storekeeper,

    Something is confusing in the numbers.

    If the primary is 5 X 1 and the rear sprocket is a 44, and the output sprocket is an 11, the final ratio is 20 X 1.

    Divide 11 into 44 and you get 4 X 1, then multiply by the primary ratio of 5 X 1 for the final 20 X 1 ratio.

    We supply the EZM kit with the Q-Matic drive with a stock 15.48 X 1 ratio. The majority of EZM kit owners are in the 200 to 250 pound range, and no reports of pedal assisted take-off is needed [39 MPH @ redline].

    If you change the rear sprocket to a 56 tooth on your current setup the final ratio would be 25.45 X 1 and surley will climb most hills, however it is important to note a few numbers. At 25.45 X 1 your motor will be turning numbers that will limit the top speed to 23 MPH [at redline of 7800], and if ridden to 30 MPH [10,000 RPM]it will most likely supply you with lots of little parts that once was a motor.

    The 4 stroke motor is difficult to determine the RPM level because it is so smooth and quite, and is easily over revved. While the 49 CC 4-stroke is a great motor, it can not stand running at 10,000 RPMs for an extended length of time [BTW your car motor would also become scrap if run above 10,000 RPMs]

    If you elect to increase the rear sprocket size for better take off, be VERY careful, and it might be wise to install a tachometer.

    It is almost impossible to break the little 49 CC 4 stroke, but it can be done with radical ratios.

    Hope this information is helpful, and any comments concerning the EZM Q-Matic drive is for information purposes only, and not for advertizing our product.

    Have fun,
  8. StoreKeeper

    StoreKeeper Member

    The kit I got is the 4 stroke(See attachment)

    I'm not sure if it's the Q-Matic


  9. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi Storekeeper,

    Your dealer offers several 4 stroke kits including the EZ Motorbike kit.

    The EZM kit employs an American made drive system and is easy to identify. EZM's Q-Matic drive system contains a HD wedge belt, whereas the 4G uses a T-Belt. The 4G has a very large rear primary pulley, and the cover doesn't completely enclose the primary drive. The Q-Matic primary cover is approx. 2" wide and completely covers the exterior of the drive.

    The 4G T-Belt is flat and the teeth ride on notched pulleys, whereas the Q-Matic primary belt has a "V" configeration and rides in "V" belt pulleys.

    There are many differences between the drives including width, bearing support,and clutch location. But I suspect you have the 4G, as the EZM primary ratios would do poorly with a 44 tooth rear sprocket [12 X 1, 50 MPH @ redline]. The EZM kit with the Q-Matic drive ships with a 56 tooth rear sprocket.

    Have fun,