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<  General Scootering  ~  Symptom Of Clutch Failure?
Jeff
PostPosted: Wed Sep 07, 2005 11:38 am  Reply with quote
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My Stella has developed a chatter and loss of power at low RPMs in third and fourth gear. If I rev it out a bit it goes away, but the noise has been getting progressively worse over the past couple weeks. It kind of reminds me of a clutch going bad in a manual transmission car. Is this a possibility? I have about 4500 miles of very hard riding on it. What do you think?

J
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jsyx
PostPosted: Wed Sep 07, 2005 11:48 am  Reply with quote
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hey Jeff-
Not really related to your problem...
but i just wanted to thank you for the pipe. We bolted it on and threw a 105 in the stack and it seems to be running great!!!
Come on dude, IT'S NOT THAT LOUD!!!

thanks again and good luck with yer clutch?!?

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Jeff
PostPosted: Tue Sep 27, 2005 5:07 pm  Reply with quote
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freakin eureka!

I found the source of that rattle finally. The spacer nut that the cooling shroud bolts into had worked it's way loose from the cylinder stud. That bastard rattled like a mofo at certain RPMs.

The loss of power seems to be mostly in my head, as usual. Maybe I was trying to talk myself into the cosa clutch or something.

The stella loves cool days like today though.
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Mojo Willy
PostPosted: Tue Sep 27, 2005 9:25 pm  Reply with quote
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Why DO our bikes run better on cool days??? Is it just the adrenaline rush or is it real? We use to ice our fuel line on dragstrip cars, come to think of it. Maybe there are some physics going on...

Mojo Willy
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nate
PostPosted: Tue Sep 27, 2005 9:45 pm  Reply with quote
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The colder air gets, the denser it is. If you take a balloon and fill it with air and move from a very warm room to a very cold room, you can see that the balloon shrinks. If you were to have a balloon of the same volume in the cold room, it'd actually have MORE air in it.

So your scooter is breathing in the same sized 'breaths', but it's getting more air- meaning you're getting a more volatile reaction in the cylinder. Same pricinple as a turbo or a supercharger, which use compression to force extra air into the cylinder.

Cold weather is a very low-rent turbo.

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Brad
PostPosted: Tue Sep 27, 2005 9:46 pm  Reply with quote
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Quote:
Why DO our bikes run better on cool days??? Is it just the adrenaline rush or is it real? We use to ice our fuel line on dragstrip cars, come to think of it. Maybe there are some physics going on...


Did you maybe ice the fuel to keep it from evaporating, to prevent vapor lock?

I've noticed that my scooter runs better in the cold also. I think that it has something to do with cool air being more dense, so it can pump more of it in.

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Brooke
PostPosted: Tue Sep 27, 2005 11:17 pm  Reply with quote
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nate wrote:


Cold weather is a very low-rent turbo.


So why isn't my scooter so much faster in the winter? The idea is right on but an engine doesn't need more air or more gas, but will run best at the exact optimal fuel to air ratio. Some people will say, an engine will run best when it's lean. This is not true. I think it comes from the fact that most engines are set up so they run normally on the rich side of that magic perfect ratio and when they encounter a weather condition that has a higher oxygen density (i.e. cool and dry. Don't discount dry. Water takes up a lot of space, relatively, too) the engine runs better because it's closer to it's optimal ratio. One could set this fuel air mixture closer to optimal in the other parts of the year but then if they didn't adjust for cooler drier air they could be in trouble if say, they were driving out by stillwater in the twisty up and down stretches of road and left the throttle closed and clutch pulled in for just a hair bit too long. It's much safer to be on the slightly rich side for year round adjustment free riding and for the aide of general cooling properties of the fuel mixture. Fuel injection in modern cars takes care of all this for you with oxygen sensors. I've read about it racing that they want to deliver as much fuel as possible with out being overly rich. But I think this just comes from the balance from the opposite point of view. Personally,with scooters, I think it helps a tiny bit by reducing misfires from leaning the ever so slightly rich mix and the cooler air in your face makes you feel like you're going faster, rather than improving combustion on each stroke. All you CWC guys should clock your top speeds and zero to 60 km/h time using a GPS this winter and see. Remember to dress the same in your summer test run and when you do it in the winter to reduce the need for drag correction. don't gain any weight at the holidaze either.
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Matty
PostPosted: Wed Sep 28, 2005 6:57 am  Reply with quote
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Brooke wrote:
but then if they didn't adjust for cooler drier air they could be in trouble if say, they were driving out by stillwater in the twisty up and down stretches of road and left the throttle closed and clutch pulled in for just a hair bit too long.


Don't know what the hell you're talking about there!

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