I finally got my 140HP Mercruiser out on the water after a year long restoration, and let me tell you, I was one happy camper 
This was the shake-down run and the boat ran like a charm, well except for 1 thing...
It fired up at the dock fine and at the end of the no wake zone it popped right up on plane and ran great. I putzed around the marina (within trolling motor range) just in case something acted up and then ran down lake varying the RPM 2000-4000, everything ran fine. After stopping for 30 minutes, it wouldn't fire back up, pump-pump the throttle and nothing. I finally got it to cough, pumped some more, coughed more, pumped the throttle some more and it finally caught and ran, the carb was out of gas... (WHEW I was 20 miles down lake)
After that I decided to head back up lake and the whole way back it ran flawlessly, no sputtering or cutting out. As I approached the marina I cut back the RPMs going into the no-wake zone and the engine died,,, right when I dropped it back to idle. Not out of gear, just back to idle. I left the engine off for another 30 minutes (couple of casts and a sandwich) when it did the exact same thing. I popped the spark arrestor off the carb and had my son pump the throttle, no fuel.
Now, how the heck could we run 20 miles without a hick-up, then the carb go dry approaching the no-wake zone? (fuel tank was full, or darn near full)
I cranked the engine, pumped the throttle as before, cough, starter, cough, starter, cough, starter and it finally decides to run... I did a bit of tuning on the engine, idle RPM and mixture screws, and ran it great for another 15-20 minutes. We headed back into the dock and loaded the boat without a problem.
One thing I noticed after making the 20 mile run back to the marina was one of the shift interrupt switch wires had pulled itself loose. It wasn't able to touch anything metal and I don't see this causing the start problem, but thought I'd mention it. The engine has an EST ignition BTW.
The carb was rebuilt, new fuel pump, new water separating fuel filter, new fuel lines, new wires, cap, rotor, plugs. Heck everything on the engine was rebuilt or replaced. About the only thing that wasn't replaced was the fuel tank and anti siphon valve. I had a post a few weeks ago about my fuel tank leaking (friggin hole is the plastic tank), got that repaired and tested the fuel system to 3PSI without it leaking. I pulled feed hose off the fuel pump and tested the fuel tank from there, wonder if I screwed up the anti siphon valve running air pressure through it backwards, it did seem to take a while to pressurize the tank?
So what do you think, flakey anti siphon valve in the fuel tank? I don't think it's sucking air since I pressure tested the fuel tank, filter and hoses.
This was the shake-down run and the boat ran like a charm, well except for 1 thing... It fired up at the dock fine and at the end of the no wake zone it popped right up on plane and ran great. I putzed around the marina (within trolling motor range) just in case something acted up and then ran down lake varying the RPM 2000-4000, everything ran fine. After stopping for 30 minutes, it wouldn't fire back up, pump-pump the throttle and nothing. I finally got it to cough, pumped some more, coughed more, pumped the throttle some more and it finally caught and ran, the carb was out of gas... (WHEW I was 20 miles down lake)
After that I decided to head back up lake and the whole way back it ran flawlessly, no sputtering or cutting out. As I approached the marina I cut back the RPMs going into the no-wake zone and the engine died,,, right when I dropped it back to idle. Not out of gear, just back to idle. I left the engine off for another 30 minutes (couple of casts and a sandwich) when it did the exact same thing. I popped the spark arrestor off the carb and had my son pump the throttle, no fuel.
Now, how the heck could we run 20 miles without a hick-up, then the carb go dry approaching the no-wake zone? (fuel tank was full, or darn near full)
I cranked the engine, pumped the throttle as before, cough, starter, cough, starter, cough, starter and it finally decides to run... I did a bit of tuning on the engine, idle RPM and mixture screws, and ran it great for another 15-20 minutes. We headed back into the dock and loaded the boat without a problem.
One thing I noticed after making the 20 mile run back to the marina was one of the shift interrupt switch wires had pulled itself loose. It wasn't able to touch anything metal and I don't see this causing the start problem, but thought I'd mention it. The engine has an EST ignition BTW.
The carb was rebuilt, new fuel pump, new water separating fuel filter, new fuel lines, new wires, cap, rotor, plugs. Heck everything on the engine was rebuilt or replaced. About the only thing that wasn't replaced was the fuel tank and anti siphon valve. I had a post a few weeks ago about my fuel tank leaking (friggin hole is the plastic tank), got that repaired and tested the fuel system to 3PSI without it leaking. I pulled feed hose off the fuel pump and tested the fuel tank from there, wonder if I screwed up the anti siphon valve running air pressure through it backwards, it did seem to take a while to pressurize the tank?
So what do you think, flakey anti siphon valve in the fuel tank? I don't think it's sucking air since I pressure tested the fuel tank, filter and hoses.
