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Engine trouble
On Mon, 23 Jun 2008 14:47:38 +0000, Larry wrote:
wrote in news:7bc30477-49a6-401e-81e2- : Primer bulb on the fuel line? Yes I have one. Now that I think about it, it has oil injector but probably carburetor... Ok, first we need to use the primer bulb to test the fuel system for operation, clogged lines, stuck floats, ripped open rubber diaphram in the chinzy-ass fuel pump: Tilt the engine down to its operating position. Pump the primer bulb until it gets so hard you can't pump it any more. Keep that last squeeze on it to see if it slowly squeezes down. You have now pressurized the fuel system inside the engine, having filled the carb floats until the float valves shut off the flow. The pressure from your priming has also showed us there are no leaks because the bulb won't pump up hard if there are, it'll slowly squeeze and gas will run out "somewhere", even places you can't see. We've also learned the diaphram in the cheap pulse fuel pump doesn't have a rip or hole in it because if it did you'd be pumping gas through the hole into one of the cylinder's crankcase, flooding it with gas and the bulb will NEVER get hard that way. Now, IF you pumped that first pump or two and the bulb stayed flat and refused to refill from the tank, you either have a clogged strainer inside the tank...or you forgot to turn on the fuel tank exit valve....or you have a clogged external fuel filter if it exists. You need to find out why the bulb can't pump gas freely as it's clogged up. Isn't this easy?! Ok, we pumped the bulb at the dock until it got hard. It stayed hard even though we continued to squeeze it on that last squeeze when it got hard and didn't notice it slowly bleeding off our last squeeze. That all went well, let's go to sea trials.....more testing with this little bulb! Ok, now we need to WATCH the primer bulb before and after the engine runs like crap. We've primed the engine, already during the initial static testing phase. Crank 'er up and let it idle at the dock. If it idles like crap and we've already primed it, the low speed jets are probably clogged or we have an ignition problem. That's about all there is to a 2-stroke engine. Let's say it idles fine, well, as fine as a 2-stroke ever idles. Idle out past the boats and docks into open water and have someone ELSE keep an eye on the bulb. Don't pump it....yet. If the bulb starts to collapse on its own at any time, OPEN THE GAS CAP A CRACK and see if it fills back out....the fuel tank vent is clogged if it fills back out! Damned dirt daubers! Clear the vent, close the gas cap and try again to see if you got all the mud out of it the wasps put in. Ok, still watching the bulb for any signs of collapse, out in open water, start running the throttle up and onto plane, normally not all at once. If the bulb starts to collapse at any point, open the gas cap again and see if it refills out again. The vent is ALMOST clogged if that works. Ok, we're on plane and watching the bulb. The bulb didn't collapse but the engine started running like crap. Start to pump the bulb while the engine is running like crap. If the engine smooths back out and picks up speed, keep pumping the bulb until we get back to the dock. The fuel pump pulse line hose has a hole in it, has fallen off or is partially clogged so the crankcase gasses pumping the little diaphram in and out aren't pumping the little diaphram in and out. The diaphram was fine in our static test, but the pulse line that pulses the diaphram is blocked or leaking too bad to pump it....we ran outa gas in the carbs.... You'd be amazed at the number of boats who asked me to tow them were just so amazed when I told them to try that last paragraph so they could get back to the trailer...(c; Panicky people aren't too diagnostic of problems. Ok, we pumped the bulb and it didn't change the way the engine was running at all...it still runs like crap. Two possiblities, now, clogged high speed jets because you put the toys away WITHOUT draining the carbs by unplugging the motor at the dock and letting it run until it died from lack of gas.....or ignition problems, probably caused by the cheap-assed stator under the flywheel being all rusted up because it would have cost Mariner (or any of them) another dollar to PAINT the iron core that's shorting out....damn them all. Take it to the shop and tell them exactly what you did from my post to help them find the problem. I'm already assuming you can see water pouring out of the ****er and you see water sputtering out of the exhaust relief letting us know the thermostats have opened and it's not overheating...right? It could still have a leaky head gasket or cracked rings but I don't suppose you have a cylinder pressure guage to test it or you wouldn't have posted what you posted. ---------------------------------------------------------- The look on a boater's face when I tell him to open the gas cap a crack, or the fuel valve he forgot to open, and the engine smooths out in 15 seconds, having watched his bulb collapse..........PRICELESS!...(C; Larry, it wasn't my problem, but you sure gave a splendid answer. I learned something new. Thank you! -- John *H* |
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