1989 Chaparral 2100SX, 5.7L merc with 4bbl rochester carb. Last year the boat started to hesitate on hard throttle. Sometimes it would cough and sputter and want to stall when trying to get on plane. Over the winter I sent the carb off to be rebuilt. I thought the accelerator pump was probably going. I put the rebuilt carb on in April and had pretty good luck right off the bat. I did have an engine run on a couple of times but I opened the needle valves, I believe I am out 2-1/2 turns now, and that seems to have taken care of that problem. I had the boat out twice with no acceleration issues until last time out. I ran the kids around for a couple hours, wakeboarding and skiing, then ran in to some friends and put in on the beach of about 45 minutes. The boat started fine and I idled away from the beach for about 2-3 minutes then hit it to full throttle and once again the old problem happened where it wanted to stall. If I back off and feather the throttle I can usually keep it going, but I would really like to figure this problem out. The other thing I have noticed is hard starting once its warmed up. Before I had it rebuilt when the boat was warmed up and then shut down to pick up a skier or what ever, it would start back up immediately. No throttle, just a turn of the key, without fail. Now it cranks and cranks. Sometimes I have to take it out of gear and open the throttle some to get it to start. Maybe I have the needle valves open too much? I do have the old spring type choke, but I have verified a few times now that it seems to be opening properly. Any ideas would be appreciated. I have spoken with the company that did the rebuild a few times now and they have been helpful, but he is directing me to the choke now and I'm just not sure that is where the problem is. Thanks!
