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#1
posted to rec.boats.cruising
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"il_papa" wrote in news:1176661659.793213.280450
@n59g2000hsh.googlegroups.com: My first post here .. I launched my boat today after the long danish winter, to experience problems with my four-stroke 4HP Mariner Outboard. The motor started fine (only 4 - 5 attempts) For some reason or other the motor cuts out after a few minutes, and I have a feeling that there is something up with the fuel supply. I have an external fuel tank which is positioned below the motor's fuel inlet, so the fuel hose has to travel up before being lead through the transom and into the motor .... could this possible cause the problem, i.e. a fuel syphon problem, is there a maximum fuel hose length (mine is probably about 2m long? The motor will start again after 30 seconds or so after I have pumped more fuel to the motor and given it some choke. Any help appreciated. That pumping bulb is the finest troubleshooting equipment an outboard motor ever had..... When you pump it up, does it ever get hard and refuse to pump any more or does it just keep pumping until gas starts running out of the motor? If it starts running out, does it run out the case or the exhaust or both? What it SHOULD do is to pump until the float valve closes then refuse to pump any more getting "hard" as you can't compress the liquid. Call that "normal". Two possible problems raise their ugly heads if it doesn't.... 1) The pulse fuel pump diaphram is ripped, rendering it useless. Continued pumping of the bulb, in a 4-stroker, floods the crankcase with gas, thinning the lube oil into oblivion and causing the motor to go unlubricated until the bearings wear out or seize, completely. 2- strokers, much better engines to fix, merely flood one crankcase chamber through the pulse tube, which clears....well, unless the stupid motor is oil injected and there's no lube oil in the gas to lube the bearings you just washed down with raw gas. Premixed gas/oil 2-stroker? No problemo! If the diaphram is ripped, the pump won't pump gas uphill from the tank...fuel starvation ensues. Crank the engine and when it starts to stall, pump the bulb and see if it takes off again. If it will run with you slowly pumping the bulb, the fuel pump diaphram is ripped, replace it. If the bulb collapses when the engine is running, something is clogging the fuel flow BELOW the bulb, back towards the tank. Watch the bulb as the engine runs to see if it slowly collapses. That would indicate a good fuel pump making the vacuum, but no gas flowing up into the bulb as the vacuum increases into fuel starvation. 2) The float valve in the carb is stuck open, flooding the engine with gas as the level is way too high or is dumping raw gas down its intake. This happens when Joe Boater stores the engine WITHOUT running the gas out of the float bowl. The light elements evaporate out the various ports in the bowl, while what's left turns to that gummy brown shellac, clogging up the jets and making the valve stick. Always run the engine dry by unplugging the tank and leaving it run until it stumbles, then full choke before it stalls to suck out any gas that's left by the choke pulling a vacuum on the holes to the jets. Never store a motor with gas in the carb(s). Let us know how we did! I found a boater stranded, motor cover off, staring into the beast (V-6 Merc 150). "Have you pumped the bulb since it died?", I asked gingerly as he was bigger than me by a bit. Of course not, he took the cover off and was staring into its guts without thinking. After he cleaned off some of the major pluff mud he was knee deep in behind the motor, I told him to pump the bulb up hard. He looked at the bulb and it was FLAT!...sucked FLAT by the fuel pump. "Open the fuel tank valve and let's see if that fixes it." (I tried not to show any mirth or just belly laugh at that point.) He opened the valve, the bulb popped back out. "Now pump it up hard for me, just for old times sake." He was quite cooperative, at that point, having saved him from being towed for 10 miles to the trailer. Mr Merc roared to life and ran like new. He and his wife went on their way after a short raft up to have a complementary beer from the big white cooler....(c; I love that bulb... Larry -- |
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#2
posted to rec.boats.cruising
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In article ,
Larry wrote: fuel tank valve and let's see if that fixes it." (I tried not to show any mirth or just belly laugh at that point.) He opened the valve, the bulb popped back out. "Now pump it up hard for me, just for old times sake." He was quite cooperative, at that point, having saved him from being towed for 10 miles to the trailer. Mr Merc roared to life and ran like new. He and his wife went on their way after a short raft up to have a complementary beer from the big white cooler....(c; I love that bulb... And then, just to thank you, he kicked the crap out of you? g -- Capt. JG @@ www.sailnow.com |
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#3
posted to rec.boats.cruising
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#4
posted to rec.boats.cruising
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Thanks for the advice guys ... the motor is running much better ....
once I dealt with the fuel tank vent |
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#5
posted to rec.boats.cruising
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"il_papa" wrote in message oups.com... Thanks for the advice guys ... the motor is running much better .... once I dealt with the fuel tank vent You're welcome. Wilbur Hubbard - master mariner and master mechanic. |
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#6
posted to rec.boats.cruising
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"Wilbur Hubbard" wrote in news:%
: Wilbur Hubbard - master mariner and master mechanic. Master Baiter, too? Larry -- |
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