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Thread: What are the symptoms of weak valves?

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    Default What are the symptoms of weak valves?

    Could some one please tell that what are the symptoms of weak valves?

    Thanks,


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    white smoke
    My dear ALLAH when I loose hope, help me to remember that Your love is greater than my disappointment and Your plans for my life are better than my Dreams.

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    Quote Originally Posted by dms664 View Post
    white smoke
    i thought white smoke ring piston ki wja se hota hai . as most mechanics say k "ring pishton" khatam hain gari k
    people need to grow up sometimes and act MATURE !

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    Quote Originally Posted by jadoon1992_vxlimited View Post
    i thought white smoke ring piston ki wja se hota hai . as most mechanics say k "ring pishton" khatam hain gari k
    weak valves results lower compression.weak valve stem seals causes blue smoke
    Just Do It Your Self!!!!!

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    what the hell is "weak valves"......?

    the springs can be weak due to wear and tear over time...

    but how can valves weaken? they can deform though, is that what is meant by "weak".....?

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    Quote Originally Posted by umarkhan1 View Post
    weak valves results lower compression.weak valve stem seals causes blue smoke
    Perfectly summed up. 100% correct. To what you have said so nicely, I will add, usually leaking valve stem seal is catheterized by a puff of blue smoke at the morning start, also, at times, on the after run. Continuous blue smoke indicates worn oil control rings. Weak compression is characterized by poor pulling power up a hill amongst others. If another vehicle of the same model and year with the same load (people and luggage) can go up a hill in fourth gear but yours needs third or second, your vehicle has weak compression. Weak compression can be from poorly seating valves or worn compression rings. Both cases is bad news.

    Oil burns with a blue smoke. Water burns (steam) with a white smoke.

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    Blue smoke issue has not been developed yet at all. How can one judge the compression without using gauge?

    Anyhow, after reading replies above, the summary is that,

    The bike has not become smooth in acceleration, when I tried to twist the throttle especially in 1st and 2nd gear, engine gives me a feel that it is trying hard to accelerate but some thing is stopping it. Engine is making little jerks in quick acceleration, same feelings a rider get when a weak drive chain keeps on tightening and losing. In my case chain sprocket is in healthy condition plus no wheel jam issue.

    Bike is producing more heat than normal.

    Quote Originally Posted by umarkhan1 View Post
    weak valves results lower compression.weak valve stem seals causes blue smoke

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    Quote Originally Posted by bigmaster View Post
    what the hell is "weak valves"......?

    the springs can be weak due to wear and tear over time...

    but how can valves weaken? they can deform though, is that what is meant by "weak".....?
    No deformation, as far as I understand compression weakness due to valve seat got damage that's what he might be talking about
    ''Creativity is contagious, pass it on''

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    Quote Originally Posted by abdulrehmanrauf View Post
    Blue smoke issue has not been developed yet at all. How can one judge the compression without using gauge?

    Anyhow, after reading replies above, the summary is that,

    The bike has not become smooth in acceleration, when I tried to twist the throttle especially in 1st and 2nd gear, engine gives me a feel that it is trying hard to accelerate but some thing is stopping it. Engine is making little jerks in quick acceleration, same feelings a rider get when a weak drive chain keeps on tightening and losing. In my case chain sprocket is in healthy condition plus no wheel jam issue.

    Bike is producing more heat than normal.
    If poor acceleration is your problem, why do you think the valves are weak? To me it looks like fuel starvation. Get your fuel system checked. Start from the tank and closely look at all the components in the way of fuel to the cylinders. If all is well, check the spark plug gap. Too wide a gap will result in jerky acceleration especially in the lower gears. That brings me to the coil. A weak coil is not able to generate enough spark to jump the gap of the plug especially when the throttle is fully open at low speeds.

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    Quote Originally Posted by msabbasi View Post
    If poor acceleration is your problem, why do you think the valves are weak? To me it looks like fuel starvation. Get your fuel system checked. Start from the tank and closely look at all the components in the way of fuel to the cylinders. If all is well, check the spark plug gap.
    I thought so because there is no sign of starvation or missing, so may be either the clutch plates or valves that are not helping the engine in acceleration. Worn out/ weak valves, may be not producing the required compression, affecting the acceleration or the weak clutch plates which are not transforming the maximum power to transmission and keep on slipping while quick acceleration.

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    Quote Originally Posted by abdulrehmanrauf View Post
    I thought so because there is no sign of starvation or missing, so may be either the clutch plates or valves that are not helping the engine in acceleration. Worn out/ weak valves, may be not producing the required compression, affecting the acceleration or the weak clutch plates which are not transforming the maximum power to transmission and keep on slipping while quick acceleration.
    How can you be sure there is no sign of fuel starvation? In 1st and 2nd gear the engine RPM rises very quickly and so in these two gears the apatite of the engine is greatest for fuel. Any starvation symptoms will be most apparent here. I am assuming your bike has a carburettor. What may be happening is that the float bowl is not getting filled up at the same rate as the engine is consuming fuel. Or the needle is set too low (to save fuel) and at full throttle, the fuel/air mixture is too lean to give you the power you are looking for. Both cases can be classified as fuel starvation.

    The test for slipping clutch is as follows:

    Run your bike on a quiet road (with little traffic). Proceed at a steady speed of say 50km/h in the highest gear (4th or 5th). Slowly and progressively apply the REAR brake, your bike will begin to slow down, compensate the bike's slowing down by opening the throttle progressively. If your clutch is slipping, you will note the engine RPM is steady or increases while the bike slows down. If the clutch is good, the engine will stall because of the braking action. During this test do not depress the clutch at any time.

    BTw what bike are we talking about?

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