Join Date: Jan 2008
Location: Lake Ontario
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Rep Power: 8
Most likely you have the KBM10 transmission with a ratio of 2.14.
One other caution . . . don't assume the tach gauge for the engine is accurate, have the actual RPMs measured with a photo tachometer. The surveyor found my tach gauge was off by 200 RPM.
It's interesting to hear that PYI just told you it should be set at 18 degrees and that they weren't very helpful. Almost every comment about PYI service I've read here (and there are a lot) indicates they were extremely helpful, and they were for me as well.
In my case (PSC34, Yanmar 3JH2E, KBM10 transmission, 17" Maxprop) the PYI technician was very clear that pitch change alone was not enough to get the engine to run at 3600 RPM and that's why they recommended reducing its diameter by one inch while it was in with them for refurbishing. The tech said PYI was very familiar with "this situation" with PSCs. Although you won't be able to reduce your prop diameter without sending it to PYI, nevertheless, PYI does have the in-house knowledge (at least some of their tech's do) to give you the optimal settings for your boat. I'd call them back and challenge them further.