15hp high rpm troubles....HELP

[green_head_getter]

My 85 15hp johnson idles great but wouldnt run at high rpm unless the choke was pulled out completely. I rebuilt the carburator but now it runs good to about 1/4 to 1/2 throttle then runs rough like its boggin down. I try to choke it slightly and it always dies so it seems like it may be getting too much fuel. Wat could cause it to run so rough at high rpm? Good compression good spark

 

[AlTn]

Re: 15hp high rpm troubles....HELP

link%sync still ok?..if yes...use an inductive timing light to test spark on each cylinder at the rpm's this problem occurs..if the flashes dim or become erratic, the ignition system needs some diagnosing