we have a 2008 tahoe 195 deck boat 4.2 merc cruiser. when were trolling at 600rpms and we add throttle to go a little faster the boat stalls and shuts off. but from 600rpms to full throttle works greats. you cant just tap it up to like 700 rpms or it will stall. any suggestions of why this would happen would be much appreciated. would it have anything to do with the water filter, im not sure. please reply if you have a solution