Join Date: Sep 2007
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Yanmar 2QM/3qm questions
I'm in the process or rebuilding the transmission on my Yanmar 2QM20. I burned up a clutch. Meanwhile, I am looking at a transmission from a Yanmar 3QM30 which I may get cheap and use as an interim.
From what I understand the two engines are physically identical but for the number of cylinders but they use different transmissions. I assume the 3QM's is beefier to accommodate the greater HP?
Also, the interim transmission is 2.1 : 1 ration. I am not sure what my current gear box is. It may be 3:1 - of so will the higher gear ratio work?
Yes, i realize the original design choices were made for a reason but given that this boat was built for conditions far worse than I will ever expose it to I figure I have some latitude. The engine never works hard to move the boat at 5 knots. There's a little power to spare at 6 knts. I sail in the Albemarle Sound, always in sight of land, no currents or tide to speak of. Just a big lake.
In over my head?
First Boat, a well-equipped 1977 Camper Nicholson 31
What is all this stuff and how does it work?