bill & chris carli-
(On Edit- Here's a link to a previous discussion on this topic
http://www.c-brats.com/viewtopic.php?t=2215
There's been some discussion of the prop choices on a CD-25 before, but some of it may be burried in other discussions and harder to find. here are some things I remember.
Generally, the consensus has been that motors in the 130-135 hp range are adequate for the boat, but at the lower limit of performance acceptability. Not that it probably matters to your or to most, but with a larger motor or pair of motors, some have achieved top speeds of up to around 35 mph with a CD-25. Just stating this for comparison purposes.
Your current top speed of 22 mph at 5000 rpm could possibly be improved with a slightly lower pitched prop which would also give you a better hole shot and general acceleration. Gas mileage could be better, but only actual measurement in the boat over a period of real usage would give you the final answer. Your fuel monitor system is great for instantaneous mpg, but actual mileage can vary somewhat based on your exact usage, especially if you spend a lot of time maneuvering at low speeds, trolling, etc.
The next lowest prop below the 15 inch pitch is usually a 13, which theoretically should yield about 5770 rpm, well within your range of 5000-6000 rpm max.
This 13 inch prop would seem about ideal, but I distinctly remember that someone (Tyboo?) tried a 13 on a 130 Honda, and went back to the 15. I also remember that Pat Anderson has tried several props on Daydream with a 150 hp Honda, and eventually settled on a 16 inch piitch. So you may already be about at the ideal point.
If you could find a 14 inch prop, or one with an adjustable pitch, such as the ProPulse, that could be adjusted to 14, you might have a winner. (The ProPulse, however, is a 4 blade prop. and with the extra blade and surface area, slips less, and may be just about equivalent to a 15.) Still, if it could be adjusted in 1 inch increments, it would be a good experimental tool.
A four-blade Solas 13 inch pitch would seem a real possibility, considering all the above. Maybe someone out there has tried one and can comment.
As with all prop discussions, a lot of what is said is speculation, and sometimes the reality check in the water yields surprising and unexpected results.
I'm hoping that this foray into the topic will bring out some of those who have "been there, done that" with the 25, and save you the trouble of experimentation.
I'll now go join DogGone Dan in the Swearing Off Prop Speculation Penalty Box for Violating the Vow of Silence. 5 minutes for Mumbling Around with Second Hand Information. Bye. (And Good Luck!) Joe.
