dougie92 Posted March 7, 2009 Share Posted March 7, 2009 i have a dt125r and have fitted a full dep pipe and K&N airfilter could somebody tell me what size jets to get please?? Link to comment Share on other sites More sharing options...
wild foamy Posted March 7, 2009 Share Posted March 7, 2009 have you done a plug chop to see what the mixture is like? have a look at your current jet (take the carb bowl off and have a look) and go up by about #10 (my original jet in my DT50 was a #98 and after putting on my K&N filter, BigOne exhaust and bigbore kit i change to #115 Link to comment Share on other sites More sharing options...
dougie92 Posted March 7, 2009 Author Share Posted March 7, 2009 have you done a plug chop to see what the mixture is like? have a look at your current jet (take the carb bowl off and have a look) and go up by about #10 (my original jet in my DT50 was a #98 and after putting on my K&N filter, BigOne exhaust and bigbore kit i change to #115 ok i will do thanks but how to i know what size the jet is?? sorry if i sound stupid Link to comment Share on other sites More sharing options...
wild foamy Posted March 7, 2009 Share Posted March 7, 2009 ok i will do thanks but how to i know what size the jet is?? sorry if i sound stupid thats okay, lol, i was in that position about four months ago, its amazing how fast you can learn to maintain these little bikes. a "Plug Chop" is used to determine the fuel mixture and as a result, the jet sizes, when you add things like free-flowing exhausts and K&N filters you increase the airflow into the engine but not the fuel flow. run your bike around at full throttle for a few minutes, then whilst at full throttle (dont rev the nuts off it, just riding through the gears normally) kill the engine and coast to a stop, take the spark plug out and look at the electrode on the sparky end, if the engine is running LEAN (not enough fuel) it will be white, chalky and may have whiskers on it. a lean engine can cause overheating and in extreme cases overheat, ceise your engine and burn a hole through the piston. if the engine is RICH (too much fuel) it will be black and sootey, this wont harm your engine but it willlack power and burn excessive fuel. its sometimes better to run rich if your bike is new If the mixutre is CORRECT, the plug will look like an overcooked cornflake (chocolatey brown). this is where you should be runnign the bike at. keep changing the jets until you get it right, better to start with a bigger jet and gradually reduce the size to prevent lean running Link to comment Share on other sites More sharing options...
dougie92 Posted March 7, 2009 Author Share Posted March 7, 2009 thats okay, lol, i was in that position about four months ago, its amazing how fast you can learn to maintain these little bikes. a "Plug Chop" is used to determine the fuel mixture and as a result, the jet sizes, when you add things like free-flowing exhausts and K&N filters you increase the airflow into the engine but not the fuel flow. run your bike around at full throttle for a few minutes, then whilst at full throttle (dont rev the nuts off it, just riding through the gears normally) kill the engine and coast to a stop, take the spark plug out and look at the electrode on the sparky end, if the engine is running LEAN (not enough fuel) it will be white, chalky and may have whiskers on it. a lean engine can cause overheating and in extreme cases overheat, ceise your engine and burn a hole through the piston. if the engine is RICH (too much fuel) it will be black and sootey, this wont harm your engine but it willlack power and burn excessive fuel. its sometimes better to run rich if your bike is new If the mixutre is CORRECT, the plug will look like an overcooked cornflake (chocolatey brown). this is where you should be runnign the bike at. keep changing the jets until you get it right, better to start with a bigger jet and gradually reduce the size to prevent lean running ok thanks mate ill try get 10% percent bigger thn my standard tomorrow and go from there cheers (Y) Link to comment Share on other sites More sharing options...
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