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EXHAUST MANIFOLD ISSUE

in 2 Stroke Technical Questions 13 years ago

  • Re: EXHAUST MANIFOLD ISSUE

    by » 13 years ago

    Hello Bill,
    Thank you for your input on my problem, i was hopping for something minor to be my issue but unfortunately it doesn't look that way,
    I did pul the plugs out all 4 of them looked normal, clean them and re install them and i notice now that one of cyliders reading is about 60% less than the other, I will play again tomorrow with the wires fo the sending unit and see what happen,
    Yes I agree the loss of 50% of my RPM cannot be prop issue as I never mess from the last pitch seting,
    Also I did clean up the probes of the sending units and now the one that was reading low it reads 0 just Zero which is kind of wird, i don't know but seems very chalenging case, My reading instrument is a panel mount EIS.
    I apreciate very much taking the time to sugest some doing, I will try again tomow and see,
    By the way I pull out carburators and checked the travel of the pistons, both travel equaly and setled equaly, My full throtle today in the hangar was 3400, and the sount of the motor sounted like something was not allowing for the motor to run any harder hard to explain, like as you said I am strarting to suspect that 1 cylinder is not running, I don't know.
    Just don't want to start pulling my hair as I don't have a lot of them lol,
    Thank you Bill will see what hapen tomorrow again. Regards
    Yanis
      
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  • Re: EXHAUST MANIFOLD ISSUE

    by » 13 years ago

    Yanis,

    The exhaust joints are ball and socket joints with no gasket or seal inside. Some leakage is normal because they don't fit perfectly but the leakage should be dry black carbon and not oily at all. Just remove the springs, clean the joint and inspect it for cracks. If it's not cracked, coat the joint with anti-sieze and reassemble.

    It could be a carb problem. Each carb runs one cylinder and if one carb is running very rich, it could cause that problem. Also if one carb is getting no gas and you have oil injection you could be getting nothing but oil in one cylinder.

    Please let us know what you find.

    Bill.
      
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  • Re: EXHAUST MANIFOLD ISSUE

    by » 13 years ago

    Yanis,

    Thought of one thing you might check on the carbs. Carefully remove the carb bowls and check the fuel level in the bowls. They should be full to about 10mm from the top of the bowl. If one bowl is empty, you may have a blockage somewhere in the fuel line to that carb. Make sure both floats in each bowl are floating. If one float is sinking, the mixture can be very rich. Unscrew the main jet while the bowl is off and see if it is blocked. You can clean it with a small piece of copper wire if necessary.

    Bill.
      
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  • Re: EXHAUST MANIFOLD ISSUE

    by » 13 years ago

    Hi Bill,
    IF one of the carbs do not getting gas the cylinder will still run? will not size? By checking the float chambers and there is no gas in one of them is that a sure indication that gas is not geting into the cylinder? OR, the float chamber may have gas but can be something else that is restricting the gas of geting into the cylider? Am I thinking right? You are right the elbow connections are not perfect, and now base on you input I do anderstand that oil should not be there \, but dry csrbon as you mantioned, Is there anything like an epoxy type material that may seal the elbow joins before I re instal or just insert it into the groove of the elbow going to the manifold and the other end that goes to the mafler?
    Thank you Bill,
    Yanis
      
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  • Re: EXHAUST MANIFOLD ISSUE

    by » 13 years ago

    Yanis,

    Don,t put anything in the exhaust joints but anti seize. The joints are supposed to move freely so they don't crack from engine vibration. For a while, you will have some anti seize coming out but that will stop after a while.

    If a bowl is empty of fuel, the engine has sucked it out and more fuel is not getting in. The blockage is usually in the carb right where the fuel line is attached. There is a rubber tipped valve which the floats open and close as the fuel in the bowl goes up or down. Sometimes the rubber tip can be worn, letting in too much fuel.

    If you click on to the support tab at the top of the page, then click on engine manuals, you can download the maintenance manual that shows you exactly where these parts are in the carb.

    Bill.
      
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