Freshman Rider
Currently Offline
2008 Magnum 50RL
Posts: 56
Likes: 0
Joined: Mar 2, 2013 19:15:44 GMT -5
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Post by alecono on Apr 5, 2013 11:57:58 GMT -5
It is around 40-50 degrees in the morning when i head to school and up to 75 when i head home and it is about 5-10mph slower coming home. When the weather starts to be consistently 70+ will i need to adjust for more fuel or less fuel?
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Freshman Rider
Currently Offline
Posts: 56
Likes: 2
Joined: May 14, 2013 22:50:01 GMT -5
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Post by chihuahuas on Apr 5, 2013 12:09:29 GMT -5
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Post by alleyoop on Apr 5, 2013 12:21:12 GMT -5
Weather effects all motors even cars and trucks. It all depends on the density of the air.
When it gets warm the motors always loose power unless the fuel ratio to air and timing is automatically changed like today's vehicles which are computerized.
In cooler weather the motors need more fuel and in hot weather they need less fuel.
It makes no sense to be changing the fuel ratio mixture two times a day one for the cooler mornings and one for later in the day when the temps go up. So you can find a happy medium to accommodate both hot and cold changes. When it is summer and the temps are always up there then you can just adjust it for HOT weather(LEAN THE MIXTURE). If in the dead of winter then you can adjust it for COLD weather(RICHEN THE MIXTURE).
Alleyoop
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Post by domindart on Apr 5, 2013 21:37:02 GMT -5
I kinda realized my mustang (just sold) was a bit faster in colder weather..  |
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Post by skuttadawg on Apr 5, 2013 21:44:44 GMT -5
My scooters run better when its cold with the engine warmed up
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Post by prodigit on Apr 5, 2013 23:24:19 GMT -5
Most scoots run better with a hot engine and cold outside air. Colder air takes less volumetric space, thus more air can get into the cylinder.
When the fuel and air vapor is ignited in the cylinder, the air expands dramatically. The more air, the more it will expand. This expansion is what we call the explosion, and what causes the bike to move forward, through a delicately controlled machinery that converts this energy from an explosion, to a linear motion, and into a circular motion.
The hotter the outside air, the less air gets in the cylinder, and the smaller the temperature difference is between incoming air, and the air temperature at the explosion (Delta T, or temperature difference).
The larger the air difference (Delta T), the more the expansion will work.
That's why it some snowmobiles insulate their engine, so sometimes the engine is not cooled on the outside, but especially on small engines (like 50cc) the incoming air is what cools the motor, and it gets amazing gas mileage!
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Post by skuttadawg on Apr 5, 2013 23:46:30 GMT -5
I have seen a cold air intake get frosted when it was in the 50s and no where near cold enough to where it should have frosted up . Note this was a long metallic tube that had the intake below the bumper instead of a shorty with a K&N
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Post by prodigit on Apr 6, 2013 1:29:17 GMT -5
The early Volkswagen beetles also had that problem on a cold morning,where part of the carburetor would freeze.
Nothing too bad though, gasoline doesn't freeze at the same temperatures as water does.
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Post by millsc on Apr 6, 2013 8:24:04 GMT -5
I have mine tuned and jetted where mine runs about the same in cold and hotter weather, you get it jetted right you won't notice much or any difference regardless of the temps
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Post by carasdad on Apr 6, 2013 10:08:05 GMT -5
Weather effects all motors even cars and trucks. It all depends on the density of the air. When it gets warm the motors always loose power unless the fuel ratio to air and timing is automatically changed like today's vehicles which are computerized. In cooler weather the motors need more fuel and in hot weather they need less fuel. It makes no sense to be changing the fuel ratio mixture two times a day one for the cooler mornings and one for later in the day when the temps go up. So you can find a happy medium to accommodate both hot and cold changes. When it is summer and the temps are always up there then you can just adjust it for HOT weather(LEAN THE MIXTURE). If in the dead of winter then you can adjust it for COLD weather(RICHEN THE MIXTURE). Alleyoop As Alleyoop and prodigit said!!! We ride all winter here in Michigan even at 10 degrees out...as long as the roads are clear. My 2T Jonway Hornet with BBK....1.5K clutch springs and oversized variator runs like a scalded dawg when below 40 degrees out....jet like take off and will GPS right at 60. At 70 or above I lose 7-8 mph as the cold air is more dense soooo..... I have a 3/8 hole drilled in the back of my airbox with a rubber stopper pressed into it. For warmer weather I pull the plug and upjet slightly. This puts me right back at the same stoichiometric ratio I was running during the winter. I feel bad for those in Komifornia as they do an exhaust 'sniffer test' and maintaining the EPA stoichiometric ratio of 14:1 must be impossible with weather changes.. |
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Post by nulldevice on Apr 6, 2013 10:55:15 GMT -5
I miss the feature my first scooter had. The carburetor had a needle valve with an external knurled knob. I could reach down and make mixture adjustments as I rode down the road.
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Post by carasdad on Apr 6, 2013 11:07:24 GMT -5
I miss the feature my first scooter had. The carburetor had a needle valve with an external knurled knob. I could reach down and make mixture adjustments as I rode down the road. My first motorcycle had that. A 1970 Suzuki X6 Hustler...twin cylinder 6 speed 250 2 stroke. Man those old 2 stroke road bikes were fast!!! Yamaha made a twin like that too..I think it was the RD200 or RD250? But yes...the externally adjustable carbs were awesome. Wonder why nobody makes that carb style anymore? Dellorto is close...as you can change the jet without opening the carb..but the external needle was better....  |
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main jet
..BAD TO THE BONE..
