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Post by Putt Putt Scoot on Oct 1, 2013 23:07:37 GMT -6
I have a 2011 500cc VIP Future Champion. Got it from a friend of mine and wasn't running. Changed the oil (10W40) and did a valve adjustment (.003 Intake & Exhaust, Cold) When I first start it (no problem starting) it sounds really good. Once it warms up it has a small ticking noise. The gas tank was already full and the previous owner had used 89 octane. Any clue on what it could be?
Thank in advance.
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Post by redroush00 on Oct 2, 2013 6:21:05 GMT -6
Probably the valves you just adjusted. It is supposed to have a slight tick to them. Every scooter motor i have ever seen ticks a bit louder when fully warmed up rather than when they are cold.
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Post by sumdawgtwigg on Oct 2, 2013 15:53:36 GMT -6
It's normal, just as red said. Enjoy the ride!
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Post by Alleyoop on Oct 2, 2013 18:42:43 GMT -6
Yep, TICKY TICKY TICKY is fine CLATTER CLATTER CLATTER is not. As they say a little loose valve is a happy valve ;D Alleyoop
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Post by scooterbob on Oct 2, 2013 18:56:40 GMT -6
I think the valve clearance would decrease when the engine warms up. Metal expands when heated.
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Post by redroush00 on Oct 2, 2013 19:11:33 GMT -6
Well...short answer, it dont... all parts are heating up at the same rate so the tolerance doesnt change. I have checked my valves hot and cold and they measure the same.
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Post by scooterbob on Oct 2, 2013 23:04:32 GMT -6
I wonder why they have cold and hot settings for valve clearance ? Does a valve run hotter then the rocker arm? Does the heat variation have an effect on metal expansion ?
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Post by Alleyoop on Oct 2, 2013 23:53:38 GMT -6
Yes, the valves run really hot don't forget they get the HEAT FROM the explosion when the spark plug ignites the fuel. So the valve and stem get really hot and that is what makes them expand a little not to mention the head itself. But that is NOT the cause of tight valves when the valves get tight that means the BANGING up against the head indents the valve seats as well as the valve head making them seat deeper into the head. So it all depends on the QUALITY of the metal of the head as well as the valves themselves. So as the valves in simple terms makes a deeper hole that also makes the stem move up and now you have the rocker adjustment screw actually holding the valve a little open and you loose compression. But once the head valve seat has compressed enough that it no longer gives as much then the VALVE adjustments are less frequent. Alleyoop
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Post by Putt Putt Scoot on Oct 3, 2013 12:10:26 GMT -6
Thanks Guys, Really Appreciate it!!!
Looks like i'm good on that. The other problem I'm having is that at WOT I'm hearing bad sound from either the exhaust or air filter. Thinking maybe I need a gasket for the exhaust. Only does it when i'm riding....
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Post by Alleyoop on Oct 3, 2013 15:31:47 GMT -6
Describe the sound POPPING sound, BRAK sound, BACKFIRE sound(POW) and when? When your getting up to speed or when your slowing down or let off the throttle?
Because depending on what the sound is it could be FUEL MIXTURE or some kind of LEAK. Or get a VIDEO so we can hear it Alleyoop
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Post by Putt Putt Scoot on Oct 3, 2013 17:55:38 GMT -6
More like a BRAK Sound while getting up to speed with WOT. On slow take off and building speed, Everything sounds great. I'll try and get a video. Thanks
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Post by Alleyoop on Oct 3, 2013 18:35:56 GMT -6
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Post by Bashan on Oct 5, 2013 19:25:19 GMT -6
There are definitely differences in cold valve lash vs hot. However it's not as simple as hot = less gap, and cold = more. Depending on the combination of iron and aluminum components the cold gap can be less than the hot; and I suppose there are some engines out there where the hot is the same as cold. However, GY6 engines definitely need a larger cold gap than hot.
There's some definitive reasons that the cold gap is wider. The rocker arms expand mainly along the axis denoted by the purple arrow. This is just characteristic of metals, the long axis significantly pushes out at each end increasing it's length. However, the transverse plane expands very little so the metal part simply gets a little fatter. Therefore, the rocker expands parallel to the head but has very little expansion movement that would affect the valve gap. The cam reacts in the same manner, the lobes (blue arrow) might get a little fatter but the main expansion is along the axis of the cam. However, the valve stem expands significantly in the directions shown by the red arrow. As the valve stem heats up it expands in length and fills the valve gap set by the mechanic. The head does not have enough expansion to negate the lengthening of the valve stem.
Without this gap the valve does not close properly resulting in low compression and poor heat transfer through the valve seat. Tight valves are also the cause of a bike stalling when hot, the valves are simply not seating. When the bike cools off the valves start closing again and off you go.
By the way, since the exhaust valve gets hotter the gap should be a little wider that the intake valve.
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Post by shop242 on Oct 10, 2013 19:05:02 GMT -6
Am I wrong by saying this is chinese junk?
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Post by Deleted on Oct 10, 2013 22:53:50 GMT -6
Am I wrong by saying this is chinese junk? Well, sorta. Its all how its taken care of.
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