Originally Posted by benjytaylor
I'm guessing it is a 27P
A couple of things. That Solas Prop will probably be to higher pitch I would think you would need a 20 or 22" prop. Mine is a 15" Diameter by 19" So whilst the solas you have is probably the right diameter I think it is going to be far to higher pitch.
I have a Mirage 19" and get about 46 knots on a 7 meter Vipermax which is quite a heavy boat.
If you overprop a Honda there are two issues....
At about about 4000RPM the IAB butterfly valve opens allowing the engine to take in more air through the manifold at the back then at 4,500 RPM the V-tec kicks in allowing the engine to switch cams and this gives a big power boost and you can hear the engine note change.
So if you are not pulling at least 5500 RPM at WOT (I pull 5800 at WOT trimmed out) then you will be seriously down on performance.
The second thing is that looking at your pics the engine sits low when at rest. This is not a huge problem in itself however you must be careful when starting the engine as it can suck up water into the bottom cylinders through the exhaust thw issue is highlighted in the Honda Service Bulletin #56.....There is lots of info about this here.
Exhaust manifold modification BF 225 and BF 200
If you engine is post 2006 this should not be such a problem BTW...
Finally one thing to check is the IAB vale at the back of the engine at the bottom. This can sieze up if the engine sits low in the water. I have put a thread about this here....
225 IAB Valve
Good Luck !!!