hi guys need some help or advise on what to do, ok i just got a 2000 merc 15hp 4 strk starts up awsome and pees hard , now when i go to give it throttle it like bogs down and wants to dye, do you think its a carb issue the guy i got it from says he thinks its the timeing, i dont think so it idles great and pumps perfect this motor doesnt even look like its been used it looks brand new , now i know its been sitting a while how long not sure but is this a carb cleaning or adjustment, like i said it idles perfect please help