"Rich Hampel" wrote in message
...
First be sure that you're not 'chewing up' a lot of HP with too tight a
stuffing box. Consider Gore GFO PTFE packing for the most friction
free packing.

Most boats of that 'era' were over 'overpropped'.
Go to the "Michigan Wheel" website: http://www.miwheel.com/ and size
yourself a new prop (based on you typical / normal rpm at present vs.
the engine's power curve).
For best 'sailing' performance consider a folding prop such a Martec.
(but I dont think that you'll find a folding prop with small enough
pitch/diameter for your application.).
If your engine is an A4 go to the CDI website for an "exact match" prop
for this direct drive engine.
:-)


In article , Sebastian
wrote:

After testing that our engine reaches full RPM (over 3K) in neutral,
but in gear only reaches 2K, we've decided that the most likely cause
is too much prop. We currently have a 13RH10 2-blade prop. Any
recommendations for what is "standard" prop for Catalina 27? I would
guess a 13x8 tops? Also, any ideas for which particular prop to buy?
Don't want to shell out big bucks for Maxprop, so thinking of going
with campbell 3 prop? Thoughts?

Thanks.

Just gone through the experience of changing the prop. Apart form a lot of
time with catalogues and marine engineers try the following link
http://www.castlemarine.co.uk/pitch.htm
evntually after a wide range of solutions from the experts the chosen prop
matched that recommended by the engine manufacturer. 12"x9" RH3 driven by a
beta 13.5hp diesel 2:1 reduction on a 26' fairey atalanta. I get within
200rpm of max and pull about 6.2kts

Grahame