Anyone have a 79-99cc build w/EZQmatic?

Discussion in '4 Stroke Bicycle Engines & Kits' started by bluck, Apr 5, 2017.

  1. bluck

    bluck Member

    Joined:
    May 2, 2016
    Messages:
    104
    Likes Received:
    14
    I have a 99cc predator bike with an ezqmatic transmission and I just finished putting it together a couple days ago. I wanted to ask how is your acceleration as mines is pretty bad and I believe it's the clutch not letting it engage fast enough. My 50cc 4 stroke Huasheng can outperform it from a dead stop but once my 99cc pickups speed like 6mph clutch engages great. Even when I have it geared low it's slow. Tried 56t sprocket with small fixed front pulley, then tried bigger adjustable front pulley and still crappy acceleration top speed is same as my 50cc 4stroke.

    Can I replace the max torque clutch from the ezqmatic and use a cheetah clutch or better clutch to allow it to engage from a dead stop or is that just how the EZQMATIC is? I feel the clutch is made for 50cc 4 stroke but not good for the 99cc. Or did I mess up somewhere, is anyone else's working great from a dead stop using a 79 or 99cc?
     
  2. jbcruisin

    jbcruisin Active Member

    Joined:
    Oct 10, 2008
    Messages:
    1,114
    Likes Received:
    1
    I have one with a 79 cc Qmatic and one with the 99 cc Qmatic. You can put a heavier or lighter spring is in the clutch to make it engage whenever you want it to. The higher the RPM it engages the more low end torque you will have. To make it engage at higher rpm's you will need a heavier spring in the clutch. Lighter shoes will also make it engage at higher rpm's.
     
    #2 jbcruisin, Apr 6, 2017
    Last edited: Apr 6, 2017
  3. MEASURE TWICE

    MEASURE TWICE Active Member

    Joined:
    Jul 13, 2010
    Messages:
    2,057
    Likes Received:
    11
    I have a 3.5 Briggs and the centrifugal clutch and 12:1 ratio 26 wheel and it takes off from a stop well and is really fast. It was 20:1 ratio before but with a worn out 3hp Briggs. Hopefully the 99cc engine is in good shape and maybe stiffer spring as mention already.

    I have an extra jackshaft (Dual On Bike) on my bike left over from needing lower ratio before with the worn engine. Now to fit the new engine and a different type clutch, I have the clutch on 1st jackshaft with 1:1 ratio. With the engine I might try going 12 tooth to 13 tooth and have the engine rev higher to engage the clutch on the 1st jackshaft.

    This would achieve basically the same as stiffer springs in the clutch. Bell lock up at maybe 2400 instead of 2200 rpm.

    Not so familiar with the Qmatic clutch or other than Briggs Engine. Just thought you should know about my experience, as I was really surprised not knowing that the older engine was really not putting out the power it should have if running and well maintained. Will be checking inside the crankcase and cylinder, already check valve clearance.
     
  4. bluck

    bluck Member

    Joined:
    May 2, 2016
    Messages:
    104
    Likes Received:
    14
    Thanks guys for your input so I drove the bike more and it's finally engaging better I then proceeded to increase the first pulley for more top end because the torque was ok and I don't mind a pedal or two before starting. It's a good engine but if I would have known about its performance I would have opted for a bigger engine between the 125-150cc's if it would even fit haha but anyways still pretty fun to ride. Learned more about clutches now
     
  5. Tony01

    Tony01 Member

    Joined:
    Nov 28, 2012
    Messages:
    924
    Likes Received:
    17
    Where are you in cali? If you are in sj or nearby bring it to me and we'll make it run without pedaling.
     
  6. bluck

    bluck Member

    Joined:
    May 2, 2016
    Messages:
    104
    Likes Received:
    14
    I know its late but I'm about 6 hours away I live in southern Cali 30 min from LA. I've seen your 212 for sale was going to buy it until I saw you were far haha. I got it to run better now but I just adjusted for top speed because even when geared low it would accelerate just as slow as geared for high speed. Wish I can bring it by though maybe when I go visit my uncle in Sacramento I can stop by haha don't know when that would be though ha.
     

Share This Page