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View Full Version : how does the hotstart option work?


4strokin
03-21-2006, 05:43 PM
just as the subject says... does anyone know exactly how it works? how does it make starting easier? thanks
1fst400
03-21-2006, 05:50 PM
hot start holds the exaust valve open durring the compresion stroke. Not much, just a smige.
zeppelin
03-21-2006, 06:14 PM
Originally posted by 1fst400
hot start holds the exaust valve open durring the compresion stroke. Not much, just a smige.
that is the deconpresion...
the hot start does the oposite of a choke, it lets more air in
4strokin
03-21-2006, 06:17 PM
so... it would cause a lean condition if it were stuck open? and how does it let more air in by moving the butterfly? or is there a bypass??
1fst400
03-21-2006, 06:38 PM
Originally posted by zeppelin
that is the deconpresion...
the hot start does the oposite of a choke, it lets more air in

good to know. thanks.


On the yfz motor there is a plug neer the exaust cam, this is what confused me. I figured it is for an aftermarket hot start system. For use with an aftermarket cam that doesent have the stock decomp system.
zeppelin
03-21-2006, 06:54 PM
dont quote me on the because im not 100%, but the head on the yfz's must be the same as the older yz450 and 426f's, that had a decompretion sytem there, that was worked be a lever on the handle bars. on the 03 yz450 and 250f they switched to an auto decompression system that is actualy on the exhaust cam. so instead of created a new cast for the head they just pluged up the spot where the old system entered.