Idel stop, Spark advance, and throttle stop. on merc

[boaterntexas]

I have a 1976 115 hp merc, I got to fooling around with the "idel stop", "Throttle Stop" and "sprak advance" screws well now she doesn't purr like she use to, any one have any info on theese adjustments, and maybe so factory defualt setting. any advice is greatly appreciated.<br /><br /> Thanks,<br /> Thomas