i have recently bought a stratos ski fish boat that is 21ft it came with a 74lb minn kota maxxum trolling motor and it doesn't move the boat like it should. there has been a number of people tell me that that trolling motor is big enough for my boat and it should move it just fine, there has also been people tell me that my trolling motor is not running as fast as it should. i have put new batteries on it because the other ones were old and wouldn't take a full charge and that helped a little but people still say it is running too slow for a 74lb. so does anybody know what mite cause that or what is wrong with it. i have my speed turned all the way up to 5. thanks