loud pop when engine starts?

Discussion in 'General Questions' started by metalzombievi, Jun 23, 2015.

  1. metalzombievi

    metalzombievi Member

    recently ive noticed that when i start the motor there is a loud pop then the engine starts and runs with no problems. before the pop the rear wheel sometimes does a small skid like it cant move then theres the pop, eninge is running and its all fine. is that a problem i should worry about or fix?
     

  2. crassius

    crassius Well-Known Member

    I'd be thinking loose connection somewhere in ignition or plug cap.
     
  3. jaguar

    jaguar Well-Known Member

    the head/cylinder junction is not completely sealing.
    also you have too high a compression.
    plane the head and cylinder and add a couple head gaskets. Use "copper Coat" on all of them.
     
  4. metalzombievi

    metalzombievi Member

    ok so i check everythig and made sure it was all tightened. i went for a ride today and it did not pop at the start but im hearing a slight high pitch metal/metal type of sound like a "ting" but it rides fine and as far as i can tell acts normal. just with the added sound. dosent make the sound that offen or i cant hear it.
     
  5. jaguar

    jaguar Well-Known Member

    the standard ignition timing is more advanced which is about right for the standard low compression but not for high compression like you have.
    for high compression the ignition needs to be retarded which is what the Jaguar CDI does.
    high compression combined with overly advanced ignition timing causes detonation which is that ocassional sound you hear. take the head off and see if there are any mini craters in the piston top or the head. that is what results from it.
    Lower your compression or buy the Jaguar CDI.
     
  6. metalzombievi

    metalzombievi Member

    i took the head off a chicked the piston head, and there was no signs of pitting
     
  7. crassius

    crassius Well-Known Member

    that sound if often telling you it is time to add more grease to the bucking bar and its cam arm
     
  8. metalzombievi

    metalzombievi Member

    ok, so i have the engine sound fixed and thats fine. but now theres another problem (when isnt there with a new engine) i ran through the first gallon of gas that i mixed with about 6.4oz of oil. i used a one gallon red can. after the first gallon was out i got the seccond and put only about 3.4oz of oil and now even when i turn the throttle a lot, the engine sounds like it isnt getting enough gas. without the throttle it just dies. did i not put enough oil?
     
  9. jaguar

    jaguar Well-Known Member

    128 oz to one gallon, so 128 divided by 3.4 is 38.
    for regular engine oil you should be running 20:1 , not 38:1, so if you have non-synthetic oil you have half as much oil as is needed.
     
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  10. metalzombievi

    metalzombievi Member

    shouldnt 3.4 work? 6.4 worked
     
  11. crassius

    crassius Well-Known Member

    I run 4oz all the time on all bikes - that's 32:1 and I'd say you're close enough if you're in USA as gas is a bit diff elsewhere

    you should look to see if your throttle cable is pulling slide all the way up in the carb

    are you sure your carb is not set to rich or maybe has an air leak & is too lean?
     
  12. metalzombievi

    metalzombievi Member

    im not sure about any of the above, it ran fine when there was more oil and i had never had to use the choke. i dont think theres an air leak anywhere everything is nice and tight
     
  13. crassius

    crassius Well-Known Member

    until you learn more about carbs, why not just drain tank and try your original mix again - then you'll have more info about the problem
     
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  14. metalzombievi

    metalzombievi Member

    i draned the tank and added about 1oz more of oil at a time untill it ran the way it should. i ended up with 5.5oz of oil for it to run well. i didnt want to use the same ammount of oil as the first time because it was too rich and the spark plug had a a layer of black on it. ill ride around some today and check the spark plug. thanks to everyone for the help and advice.
     
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