dato720 Posted July 29, 2012 Share Posted July 29, 2012 Hi i have had my bike for around 3wks iv been starting it fine after a few leg braking kick the compression was really hard to kick but i manage to start it road it every weekend since i bought it no problems i started it two days ago to warm it up to check the oil etc. I went to start it Saturday no compression iv changed the spark plug (has spark) new air filter what could be wrong? rings, jets etc Link to comment Share on other sites More sharing options...
Moderator Airhead Posted July 29, 2012 Moderator Share Posted July 29, 2012 Greetings dato I'm totally umfamiliar with the bike other than i know its a single cyl dirt bike However I expect there may be some sort of compression release to aid starting, either manual or automatic. I would say check your owners manual for clarification yep, i just checked the manual and starting procedure is in there as expected see my sig line http://www.yamahaown...om.au/index.php Link to comment Share on other sites More sharing options...
dt502001 Posted July 29, 2012 Share Posted July 29, 2012 If you have the extra little lever beside the clutch cable then it's manual decopression make sure it moves freely at the motor the arm on the motor may have jamed holding the ex valve open. No lever then automatic you will have to take the valve cover to check the spring on the end of the cam sprocket and the pin that hold the valve open druing low rpm 'kinda hard to put to words but as you slowly rotate the motor you will here it click as the pin pop back in. Worst case you may have droped a valve the service life of the valve's is short ...10 races and the valves have considerable strech. The keepers chew the top of the valve apart alowing them to fall into the motor. when you last had it running did you shut it off or did it just quit suddenly? if so more than likely you droped a valve. A close inspection of the valves clearence to the cam will tell As you wern't riding it your probably lucky and not dammaged the head beyond repair. Good luck Phil K Link to comment Share on other sites More sharing options...
dato720 Posted July 30, 2012 Author Share Posted July 30, 2012 it has i bit of compression i put it in gear and stalled it as the kill switch dont Link to comment Share on other sites More sharing options...
dato720 Posted July 30, 2012 Author Share Posted July 30, 2012 its normally have good compression were i have to actually kick now i can just sit down and kick wich is wierd i normally start 3-4th kick but now it dosnt have any sign of starting. ive tried some start ya bastard did sound like it was about to but still didnt start Link to comment Share on other sites More sharing options...
Moderator Airhead Posted July 30, 2012 Moderator Share Posted July 30, 2012 obviously theres something wrong with you de-compressor as has been said, no amount of 'start ya bastard' (love that name ) is gonna fix that, Oh and stopping it by stalling isnt a great method is it! Link to comment Share on other sites More sharing options...
dato720 Posted July 30, 2012 Author Share Posted July 30, 2012 iv only done what iv been told to try im putting it into the shop as im not very good with bike mechanically just no the basics Link to comment Share on other sites More sharing options...
dt502001 Posted July 30, 2012 Share Posted July 30, 2012 Love the name "start you bastard" going to us that one. realy you need to check the decompression you neve mentioned what type yours has??? Link to comment Share on other sites More sharing options...
dato720 Posted August 1, 2012 Author Share Posted August 1, 2012 it has a lver bit i look at the the little spring on the motor (dont no whats its called) it seem ok ill just take it into the shop Link to comment Share on other sites More sharing options...
Recommended Posts