Originally Posted by Stephan
I read about different props constantly but don't know waht difference it makes.
What is the best on my 580 deep V with my Yam F100. I mostly cruise with my wife and little son. I don't even know what prop I have at the moment for I bought it like this. It planes quickly but it feels like it could go faster. At 5000rpm it goes about 50-55 km/h. Is that normal?
I have a similar set up to you,I have a 21 inch prop,the engine pulls 5700-6100 dependant on trim(up at the front equals faster but more unstable) and around 48mph (40 knots)max,I also usually cruise with my wife and son.
I am waiting for my dealer to get the next size prop bigger(more pitch) to try as I feel I would like to cruise at lower revs,and would be interested to know if this increases top speed.
I find the engine relatively rough at 3000-3500 revs(just on the plane) so also want to see if i can plane at lower revs(out of the rough zone).
One thing to bear in mind is that if you pull skiers,the engine will struggle more with a larger prop.
Yamaha advised me against a stainless prop as if you hit something,it is more likely to damage the gearbox as stainless is stronger then alloy.
If 5000 is your max revs,you could be overpropped as max power is developed at 5500
Let me know how you get on if you change the prop please