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Discussion Starter #1
I was wondering what exactly does this mean? I've heard people on the boards talk about doing this and I recently ordered a new exhaust for my 500r and it came up again as to whether the carbs would need to be rejetted. Also, I heard people discuss different stages of rejetting, what are the differences? If anyone could let me know I would appreciate it. Thanks!!
 

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JETTING

If you were to try to empty or fill a pool with extremes like a 5/8" garden hose versus a 4" firehose the same would be an analogy for how a motor works. to balance a see-saw the lever must be balanced with a fulcrum where both sides are equal. If you put a straight pipe on your bike your bike would runn leaner so to balance that you would need to allow more air/fuel mixture to enter the motor...because it exits easier. so there is a balance of fuel/air mixture that is optimum for any motor. With Carbs you should adjust them with barometric pressure changes like elevation changes...say Denver (5,000 Above Sea Level) or in San Diego, Ca at Sea Level. Electrinic Fuel Injection adjust the fuel/air mixture for you. So that is why the serious racers are constantly changing the carb settings at the racetrack, and you will find them blowing up motors sometimes, too. Humidity has some factor in it as well. Cold air expands better than hot air...all this comes into play when you get into fuel/air mixtures...timing, etc. A long winded message to say that all bikes are just like all cars/trucks, built for the average of all worlds. If you were going to drive a car in the city all of the time you would want to advance the timing, versus a car dirven on the open highways all of the time you would want to retard the timing from the factory settings. Bikes are smaller harder working motors doing the same thing...Yes I would recommend that you get the bike rejetted...or at least run it through the shop and read what the exhaust measurements are saying...most of hte racers will have the proper equipment to adjust for the optimum fuel/air ratio. IF yo don't like the adjustment you can reset it It's not a difficult proceedure, it just takes some time and patience doing it right. You may not have to rejet depending upon lots of factors like altitude, and just what pipe you put on the bike...The science is really cool to understand, and I wish tha tI could explain it in bettter detail...
 
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