I have a Suzuki 2005 DF60 that runs rough at 3000 RPM. Starts fine, but when I increase speed to about 3000 RPM, engine "throbs" and runs roughly. I changed fuel filter, fuel lines and primer bulb, spark plugs - still no improvement. My next step was to change the gas (was fresh) and put some injector cleaner in in case it is being caused by dirty injectors. The marina can't look at it for a couple of weeks so i am looking for any advice anyone can offer. Thanks in advance.