2gm20f Fuel Pump leak
- Thread starter Travis
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Travis...
sounds like you have a pump diaphram that's split. You'll need to either rebuild it or replace it. Would also suspect fuel has leaked into the engine oil sump, making it necessary to drain and replace the oil and filter while you're at it. I wouldn't run the engine until all this is done.
sounds like you have a pump diaphram that's split. You'll need to either rebuild it or replace it. Would also suspect fuel has leaked into the engine oil sump, making it necessary to drain and replace the oil and filter while you're at it. I wouldn't run the engine until all this is done.
Dan
Thanks for the info. I tightened the inlet and outlet banjo fittings and tightened the bolts that hold the pump to the engine and I think I've stopped 90% of the leakage. Now there is just a weep of engine oil.
I'll change the oil and filter this week.
Question: When you start your engine for the first time at the beginning of the season, do you pull the stop cable and turn the engine over for apprx 10 seconds to get oil to the bearings? Thanks,
Travis
Thanks for the info. I tightened the inlet and outlet banjo fittings and tightened the bolts that hold the pump to the engine and I think I've stopped 90% of the leakage. Now there is just a weep of engine oil.
I'll change the oil and filter this week.
Question: When you start your engine for the first time at the beginning of the season, do you pull the stop cable and turn the engine over for apprx 10 seconds to get oil to the bearings? Thanks,
Travis
Good luck with your fuel pump leak. When I start my engine (like last week) for the first time in the season after the winter lay-up, I close the raw water intake seacock, pull the fuel cut-off out, flip the decompression levers and hit start. I usually crank the engine for a few seconds, stop, and then do it again. I think this is the suggested method recommended by Yanmar to get some oil up into the cylinders. Then reverse the above, and hit start. My engine always starts right up.
By the way, you can do just the same thing by hand with the 2GM20F. Instead of cranking with the decomp levers thrown/raw water intake closed, and fuel shut off, just turn the alternator belt by hand a few times. That will also bring a bit of oil up into the cylinders.
By the way, you can do just the same thing by hand with the 2GM20F. Instead of cranking with the decomp levers thrown/raw water intake closed, and fuel shut off, just turn the alternator belt by hand a few times. That will also bring a bit of oil up into the cylinders.
Just word of caution. Years ago I had a H28. I discovered the fuel pump was bad (could not manually bleed air from the system at the engine's secondary fuel filter). I don't recall the Yanmar engine type unfortunately, but the Yahmar parts distributor said they were not repairable. For a few bucks I bought the new pump, along with all the banjo fuel fittings, gasket, etc. The pump works on the movement of an arm that's inserted inside the engine block and rotates off of a cam. A bad pump should be replaced. I'd change the oil as recommended. The caution is not to have any leaks (zero) coming from your fuel pump. Use new banjo fittings on all lines you need to reconnect as you'll never get them to reset in the exact same spot again. These engines work best when there's positive fuel pressure and no air in the lines. Allowing any leaks is asking for trouble at sea. Good luck.
Travis & Ron...
Travis: I looked through my Yanmar parts manual to see if there was a part number call-out for the fuel pump diaphram. Unfortunately there does not appear to be one, which means you will need to replace the complete pump assembly. It is the same pump used on the 1 and 2 GM engines as well, so should be common to find and obtain (Torresons; Mack Boring or other Yanmar dealer).
As far as the first start up of the season, Warren stated the best way to do it--I do it that way too. When I actually start it, I close the engine shut-off (actually opening the fuel flow), set about 1/4 throttle, then engage one decompression lever at a time, which helps the engine quickly build RPM's, pump oil, and lets me know if I need to bleed out any air if it doesn't start right away or has trouble running on all three cylinders.
Ron: It's not the banjoe fittings that distort when tightening, it's the copper washers used as gaskets on either side of the banjoe face that won't seal as well as the first time they are compressed. Just like the old VW Bug oil plug copper gasket (and newer cars too).
Travis: I looked through my Yanmar parts manual to see if there was a part number call-out for the fuel pump diaphram. Unfortunately there does not appear to be one, which means you will need to replace the complete pump assembly. It is the same pump used on the 1 and 2 GM engines as well, so should be common to find and obtain (Torresons; Mack Boring or other Yanmar dealer).
As far as the first start up of the season, Warren stated the best way to do it--I do it that way too. When I actually start it, I close the engine shut-off (actually opening the fuel flow), set about 1/4 throttle, then engage one decompression lever at a time, which helps the engine quickly build RPM's, pump oil, and lets me know if I need to bleed out any air if it doesn't start right away or has trouble running on all three cylinders.
Ron: It's not the banjoe fittings that distort when tightening, it's the copper washers used as gaskets on either side of the banjoe face that won't seal as well as the first time they are compressed. Just like the old VW Bug oil plug copper gasket (and newer cars too).
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