XS650 running question?! help

[Nickyd]

i have a 1981XS650 SII. i can start the bike up and ride or let it idle. but after about 5-10 mins then engine races, rpms go higher and i don't know why? Then when i shut it off i cant get it started again?? it just wont fire up.. I don't know why? Could the 2nd start be that the battery is dead? i cant honk the horn or anything on the 2nd start up try. but why would the engine race? or are they 2 diff issues?
Thank you

 

[xjwmx]

Where is your idle screw adjusted? Is there room to back it out more? If so, then when the revs go up next time, make sure the choke is pushed all the way in and turn the idle screw out until the speed is right. To start it cold in summer you'll have to pull the choke out about half way.

 

[Nickyd]

well it start with the choke the first time then i can shut the choke off and the bike will run fine. its then a few mins later where i will give it gas, then the idle wont come back down? and the throttle able is adjusted fine and does not stay open. then i get nervous and shut the bike off.. and cant start it again lol
Thanks!