I repowered with a new Yanmar
4JH4-TE 75hp in 2010, put boat
late that summer, only ran engine
for 7 hrs. Didn't notice vibrations. Summer of 2011, had the cutlass bearing replaced, prop resized/pitched to increase WOT rpms, but ultimately, never got the boat
in the water
. This year, after delays due to painting hull
, finally got boat in water in Sept. In doing speed runs to check out effects of prop resizing, I'm feeling vibrations at 2400 rpm
Looking at the prop shaft while underway, I think I see that it is "blurred", that the shaft is vibrating or running out.
I measured shaft runout with dial indicator to be .008" -.010". What would be allowable runout specifications?
Do I need to be concerned that the engine
was originally installed with a marginally sloppy cutlass bearing, and now that the bearing is brand new and a tight fit, that the engine should have been realigned, on general principle? Someone also said that the alignment should be checked anyway just by the passage
of time since a new engine install. Agree? Despite only having 10hrs on the new engine install?
Thanks for any help