i am a newbie to boats as i have just purchased my first got it last friday she is 1988 sunchaser 1702 deck boat with a 3.0 alpha 1. i was told when i bought it that it had a cracked block after getting it home i stuck the out drive in a 55 gal barrel filled with water and got her to fire up but would not idle so i let it for at a high idle so i could find where it was leaking water form the block at and sure enoug under the manifold took appart and "glued her back together and again would not idle this time on the muffs so i let her run at a high idle (i am guessing about 1500 as my tack is not working right now)for about 10-15 min and no water leaking but as soon as i pull the throtle back to let it idle is start to chug and run ruff until she dies after which i can take the throtle and give it a little squirt hit the key and she will fire right back up and to a high idle again a run just as smooth as can be the carb was "rebuild earlier in the spring" andi do have the reciept where the previous owner had paied some one to rebuild it at a marina i am up for ideas here on what is could be and thanks in advance for all your help as i have already learned so much from readding these forums