Post Number: 182
|Posted on Sunday, December 10, 2006 - 04:57 pm: ||
I thought I would pass on this experience.A friend who has a medium sized wood hulled yacht had a problem with his P55 engine .When he engaged reverse the engine would not reach it's maximum revolutions . Those of us who have these engine would be aware of the throttle arangement and how it is coupled with the selection of forward and reverse. Maximum revs and performance was obtainable in forward gear but reverse was lacking. We know that throttle movement is the same both in forward and reverse and the carby butterfly opens to the same degree. So what was the problem . I corresponded with my friend on this and suggested a few ideas ,none of which I had much faith in ,however we had to start some where.
The solution to this was the prop. The design of the prop was such that in reverse it was not meant to have it's full efficiency . Full efficiency was in forward . Reverse had not been used much if at all .Over a period an abnormal build up of marine growth had accumulated on the reverse face of the prop.....this was enough to effect the performance !
My friend dived and cleaned the growth off and now the performance is back to normal.
Something to remember!!