phataskala
Recruit
- Joined
- Aug 30, 2011
- Messages
- 1
I'm hoping to get some opinions on a course of action for my 18' 1997 Starcraft open bow with a Mercruiser 3.0LX engine. It won't run at idle (stalls out) and is not developing the proper power at high throttle settings, but runs OK at mid throttle settings. I haven't taken any diagnostic steps but plan to start from the fuel tank and work my way to the carb.
I bought the boat about 6 weeks ago and have had it out a handful of times. It has been running fairly well, but was having a hard time starting. Finally it wouldn't turn over at all and I had the starter replaced and now it starts well when warm, though now it won't run at idle at all (before was rough) and still takes a half dozen tries to start when not warm. Was out last weekend and it wasn't developing power at higher throttle settings. We did some tubing with the kids at med/low speed and after a while its power generation continued to degrade. On the way back to the dock it began knocking. Oh, and the tachometer and water temp gauge have been acting wierd (intermittent, sometimes seeming accurate, mostly not sensical at all) since I bought it and so i'm not sure what to believe for tach and temp (oil temp seems to be working ok - it has not showed hot as far as I can tell). I was thinking a fuel issue would cause it to run lean and hot and was causing the knocking. I've heard that fuel pumps give out gradually if the diaphragm ruptures, which would explain why it doesn't run at idle (starved at low rpm), and not well at high rpm (not enough supply), but ok at mid range throttle (pump can keep up with limited demand). Is that the case (gradual failure), or does a fuel give out all at once and leave you dead in the water?
I plan on starting on the fuel system - checking the tank for water, changing fuel filter, then checking to see if the pump is pulling the right pressure. I talked with a mechanic about the symptoms and his first thought was the carb needs to be rebuilt. If anyone has any suggestions I'd love to hear them.
Thanks.
I bought the boat about 6 weeks ago and have had it out a handful of times. It has been running fairly well, but was having a hard time starting. Finally it wouldn't turn over at all and I had the starter replaced and now it starts well when warm, though now it won't run at idle at all (before was rough) and still takes a half dozen tries to start when not warm. Was out last weekend and it wasn't developing power at higher throttle settings. We did some tubing with the kids at med/low speed and after a while its power generation continued to degrade. On the way back to the dock it began knocking. Oh, and the tachometer and water temp gauge have been acting wierd (intermittent, sometimes seeming accurate, mostly not sensical at all) since I bought it and so i'm not sure what to believe for tach and temp (oil temp seems to be working ok - it has not showed hot as far as I can tell). I was thinking a fuel issue would cause it to run lean and hot and was causing the knocking. I've heard that fuel pumps give out gradually if the diaphragm ruptures, which would explain why it doesn't run at idle (starved at low rpm), and not well at high rpm (not enough supply), but ok at mid range throttle (pump can keep up with limited demand). Is that the case (gradual failure), or does a fuel give out all at once and leave you dead in the water?
I plan on starting on the fuel system - checking the tank for water, changing fuel filter, then checking to see if the pump is pulling the right pressure. I talked with a mechanic about the symptoms and his first thought was the carb needs to be rebuilt. If anyone has any suggestions I'd love to hear them.
Thanks.
