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Old 07-10-2018, 06:16   #61
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Re: Yanmar low RPM under load

Or a constricted exhaust system. Might check it all the way back for an internally collapsed hose or animal nest. Best wishes.
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Old 11-10-2018, 17:49   #62
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Re: Yanmar low RPM under load

So now I am really confused. The compression test showed, 410, 395 and 400. So what now. Is it the fuel systems, maybe the governor, or fuel pump. I checked everything else I can think of.
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Old 11-10-2018, 18:11   #63
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Re: Yanmar low RPM under load

Like Roland said it could be restricted exhaust flow. How old/how may hours are on your exhaust mixing elbow? If that is restricted from build up it could account for your problem. Other than exhaust restrictions I would be looking at fuel delivery.
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Old 11-10-2018, 18:14   #64
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Re: Yanmar low RPM under load

Good news compression is ok :- )Yes I'd suspect the fuel system now. Did you check that all the injectors were spraying according to manual description? Rare for injector pump to fail unless it's had lots of water or diesel snot go thru it. I'd check for any air leaks & the injectors spray pattern.
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Old 11-10-2018, 19:20   #65
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Re: Yanmar low RPM under load

The exhausted elbow was replaced about 2 years ago and this the first thing I checked.
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Old 11-10-2018, 19:23   #66
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Re: Yanmar low RPM under load

The mixing elbow and exhaust was the first thing checked and nothing found. The mixing elbow was replaced about 2 years ago and did not have any buildup inside.
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Old 11-10-2018, 19:59   #67
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Re: Yanmar low RPM under load

Quote:
Originally Posted by jmurray109 View Post
So now I am really confused. The compression test showed, 410, 395 and 400. So what now. Is it the fuel systems, maybe the governor, or fuel pump. I checked everything else I can think of.
Now is the time to recheck every that you have already checked and ruled out

One sure way to eliminate many fuel items in one go is to set up clean jug of fuel, just a couple of quarts and gravity feed it direct to the injector pump.
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Old 11-10-2018, 20:44   #68
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Re: Yanmar low RPM under load

See A64 post# 3
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Old 12-10-2018, 17:26   #69
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Re: Yanmar low RPM under load

Check the timing. Check the Fuel. Check the exhaust. Check the air supply. Change any blocked filters in air and fuel. That is pretty much it. If the engine has a LOT of hours on the clock--check the pump and injectors for wear.

Oh--and check that your throttle setting actually works and that it does open the pump when you advance it.
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