Ok, just to preface this, this could be completely  in my head.  I feels my bike just seems to run better at night. It has the stock jetting so typically night= cooler thus more dense air = running leaner?

I though these bikes typically run lean already. Is this a typical experience?  I have only been riding for a couple months.

So, i guess my question it, how do i get it to run this way all the time? lol

No matter how you are jetted, running at night or in the fall/ spring with cool dense air will always make you engine work better. Bike or car. I love going for drives in the fall with the cool dense air, it makes a difference.

You want to jet for the situation you mostly ride in, so like most people, thats during the day.

Its simple. The colder the air the more oxygen it carries. More air helps to make a bigger bang. So running at night means it will always run nicer. Also remember the colder air is also keeping down the cylinder temps as well, which also helps the banging.

I have heard this about both cars and motorcycles..........explained to me that both the cooler air, and the moisture content contribute to better running..............

Cooler air is denser air so should be more oxygen = more power

Moisture......I know that WWII aircraft used water injection...cooled engine and created "steam" to poost power output........




I had a honda scooter which ran to the rich side.......could tell by the color of the exhaust pipe an the color of the spark plugs........Most certainy ran better on cold days, cool mornings.........ran poorly on hot days......

conflict:  Moist air is less dense than dry air...........but moisture is H2o and that is oxygen........cooler iar is more dense than hotter air....

Hmmmmmm

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Quote from: twocool on September 03, 2010, 10:23:10 PM

conflict:  Moist air is less dense than dry air...........but moisture is H2o and that is oxygen........cooler iar is more dense than hotter air....

O2 is required for combustion, and this produces H20 & CO2+random compounds. I do not know why moist air would boost power unless its not enoughwater to where lack of compression is not an issue but can turn into steam which is compressible?

Water injection or some mixture of water and alcohol are often used for pre-ignition/detonation control in some seriously modded out engines. I'm no history buff but I think the water injection was used in WWII planes because they were trying to launch big ass planes off a carrier.

Quote from: Deros514 on September 04, 2010, 10:54:10 AM
Water injection or some mixture of water and alcohol are often used for pre-ignition/detonation control in some seriously modded out engines. I'm no history buff but I think the water injection was used in WWII planes because they were trying to launch big ass planes off a carrier.

Correct about the water and water alcohol injsection.....was to control preignition....

I 'm not sure it was needed in carrier launches, as catapaults offered all the acceleration which was needed........

What they were after was "momentary" extra power, when needed, to get the bad guy off your ass.....

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Actually water injection used to be used in hot rods also. Not long ago I came across an old water injection manifold but passed it up. If you think about it, when water is put into a hot cylinder at the right time instead of putting out the flame it will vaporize and add more hydrogen and oxygen making a bigger bang, = more power, The other theory also explains the same thing but does it on the principle of steam, when you make water into steam it takes up more space, forcing the piston back faster and harder. But you cant just dump water into an engine. it has to be supplied right and there a few other mods you need too I believe, different plugs and so forth.

Quote from: Chanse on September 07, 2010, 05:38:58 AM
Actually water injection used to be used in hot rods also. Not long ago I came across an old water injection manifold but passed it up. If you think about it, when water is put into a hot cylinder at the right time instead of putting out the flame it will vaporize and add more hydrogen and oxygen making a bigger bang, = more power, The other theory also explains the same thing but does it on the principle of steam, when you make water into steam it takes up more space, forcing the piston back faster and harder. But you cant just dump water into an engine. it has to be supplied right and there a few other mods you need too I believe, different plugs and so forth.

I don't think that the water is broken up into its elements, H and O.........I think it pretty much stays water....just goes from liquid to vapor, which is a higher enregy state, which causes a cooling effect......

I think you will find that it takes a huge amount of energy to break the bond of H2O into its elements, probably more engery than the "burning" of the resulting hydrogen would produce..........making hydrogen by electrolosis (electrical power) is a losing probosition.........(in Iceland, they use geothermal energy, which is nearly free, to produce electrical energy, to produce hydrogen, to power cars...........This only makes sense because the geothermal is nearly free.......otherwise it would be a totally stupid idea!)

I am also not so sure about the "steam effect"...........

What the water, or alchohol, or water and alcohol injection does, is to cool.........It has the exact same effect as higher octane........so the engine can be designed for higher octane (higher compression ratio, and timing advance) and the water injection prevents engine "knock".  Basically this means maximum  power produced for a given engine displacement.........

Jet and turbine engines also use water injection........part of the better performance is from more mass (water vapor)being ejected throught the exhaust.....


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