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problem scrambler 400 idle

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Old Jun 18, 2010 | 02:51 PM
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Default problem scrambler 400 idle

when i turn on the scrambler at 1/2 choke it ideal normal no problem but when i turn the choke off it rev to high rpms? what cause this...
 
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Old Jun 18, 2010 | 09:07 PM
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anyone?????
 
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Old Jun 19, 2010 | 07:36 AM
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Usually with a 2 stroke, high or runaway idle speed is an air leak, when lean, 2 strokes tend to rev higher. When it is idling high, spray carb or brake cleaner around the carb, intake,exhaust, and if the idle suddenly changes, you found the leak. There is also a chance a seal on the motor is leaking, this would allow it to suck air into crankcase, leaning out the mixture. If you dont find a leak on the top end, spray around the gasket surfaces on the jug, and cases to see if you are sucking air on the bottom end.
 
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Old Jun 21, 2010 | 10:29 AM
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i think there mite be leak around the oil system not sure yet have to get a can of carb clean to make sure. the carb seems fine but not 100 % sure i mite pick of a rebuild kit for it... i will let you know tonight thanks for the reply..
Originally Posted by 95wolv
Usually with a 2 stroke, high or runaway idle speed is an air leak, when lean, 2 strokes tend to rev higher. When it is idling high, spray carb or brake cleaner around the carb, intake,exhaust, and if the idle suddenly changes, you found the leak. There is also a chance a seal on the motor is leaking, this would allow it to suck air into crankcase, leaning out the mixture. If you dont find a leak on the top end, spray around the gasket surfaces on the jug, and cases to see if you are sucking air on the bottom end.
 
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Old Jun 23, 2010 | 06:50 PM
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Pilot jet is plugged
 
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Old Jun 25, 2010 | 05:39 PM
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do a compresion test....my buddy's was doing that and it was a head gasket
 
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Old Jun 25, 2010 | 06:40 PM
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you have an airleak most likely. turn up the air fuel screw.
 
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Old Jun 25, 2010 | 06:49 PM
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Tyler, if he does have an air leak, it would be best to repair it, not bandaid it by adding more fuel, if it got suddenly worse, he could burn up the motor.
 
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Old Jun 25, 2010 | 08:08 PM
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Originally Posted by 95wolv
Tyler, if he does have an air leak, it would be best to repair it, not bandaid it by adding more fuel, if it got suddenly worse, he could burn up the motor.
i agree 100%. but chances are that it wont get worse. i sure wouldn't want to go into the internals of a big utilty machine. its a pain. i would just richen up the air/fuel mixture screw and keep an eye on it and see if it gets worse. my .02
 
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