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Old 02-19-2020, 09:37 AM   #19
DavidM
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City: Litchfield, Ct
Join Date: Aug 2012
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I owned two of the Yanmar 6LY 370s in my last two boats. There is a very easy test for "tired". While on your sea trial underway at about 2,000 rpm, hold your hand in front of the black hose on the starboard side of each engine that terminates above the air filter element. If you feel significant pulses, it is tired. If you just feel light pulses or usually none, it still has a lot of life in it. You are measuring blowby by using what TFer Ski calls a redneck blowby test.

If the engines pass that test, then everything else is external to the block and can be replaced a lot cheaper than repoweriing.


Also if you want to go slow, that engine will handle slow fine at 1,500 or so rpm and will burn about the same fuel as a similar displacement Lehman or Perkins 135.


David
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