Honda bf50 4 blade prop on 16 cruiser

S

seabeagle

New member
Hit a log last night and damaged my prop and cavitation plate a bit. I'll be putting the spare prop on and welding the plate but, I started thinking about changing from a 3 blade to 4 blade. A local prop shop around here said that I would get better hole shot with the same top end. I currently have an 11.1 X 13 and turn 5600 rpm with about 24.5 mph gps speed average and poor hole shot. We travel with 2 people, 2 beagles, and lots of gear. I consider the overall boat to be pretty heavy (see my album). I would like better hole shot and better top speed if possible. Does anyone have any experience with 4 blade on this size of motor? Below is a chart from the Honda accessories catalog with their 4 blade offerings. Which one might work the best?

BF35-BF50/BF60
Solas Honda–4 Blade Aluminum
Propeller Dimension

Blade Diameter Pitch Rotation Honda Part Number
4 11-7/8 9 R 58134-ZV5-009AH
4 11-3/8 10 R 58134-ZV5-010AH
4 11-1/8 11 R 58134-ZV5-011AH
4 10-7/8 12 R 58134-ZV5-012AH
4 10-1/2 13 R 58134-ZV5-013AH
4 10-1/2 14 R 58134-ZV5-014AH
 
On my 22 with 90 honda I ran a 4 blade and liked it a lot. It did have a better hole shot, ran straighter, and ran bow down a little better. I had to go up or down a pitch from the three blade, I think it was up but not sure anymore. get one on each side of your current pitch and try it out.
I also had a 4 blade composite prop on my 19 star craft with a 70ho 2 stroke. That 4 blade ran very well on that boat. even trolled slow well. Really lifted the boat out faster and flatter then the 3 blade I had before.
 
Usually 2 degrees less pitch from the 3 blade is the starting point. Dealers in our area will let us try different props as long as we don't damage them.
 
Fixed the cavitation plate and put the spare prop on. We're out on Lake St. Clair right now and I did some comparisons.

Spare 11.6 X 11 3 blade prop: great hole shot, easily cavitates/ventilates, 5600 rpm-20.8 mph gps speed, max 6400 rpm-25 mph gps speed.

Original 11.1 X 13 3 blade prop: poor hole shot, occasionally cavitates/ventilates, max 5600 rpm-24.5 mph gps speed.

I like my top speed with the original and keeping the rpm around 5600 max. Still thinking back to the 4 blade Honda options, one of the two in the middle would be in the range? How much effect does prop diameter have?
 
Ok, I spoke with the dealer that I got my boat from and he recommends the 4 blade 10 1/2 13 pitch. Does that sound right? Is there a way to calculate it before I order one. I don't have any local dealers that will let me test and exchange them.
 
There are several pprop calculators on the web. Just do a search and you will find them. Usually when going to a 4 blade you eith decrease the pitch by two or the diameter by 1-1.5 inches. You will be slinging more weight at the prop, so change is required to maintain RPM's.
 
Well, I just tried a four blade 10.5 X 13. Terrible holeshot and 20 mph at 5100 rpm max. 5600-5900 rpms max would be preferred. I suppose that if the motor had more power in theory, it could have worked. Would the 11 pitch from the above chart be best? My Dory dealer is not quite up to par on the subject.

Also I found out why this thread is so sparse. A call to me today revealed that several of the resident experts (which will remain unnamed) on the site are boycotting and giving me the silent treatment. It's sad because their knowledge would only improve the thread. At age 38, I hate to be the only adult in the room.

Anyway, I will continue trying different props until one meets my needs and post the results for everyone. And yes I've tried the prop calcs on the web but none differentiate from a 3 or 4 blade that I've found.
 
Props are funny things. I never comment on which one will work unless I know for certain as every single time I have speculated I have been flat out wrong. Perhaps I am an idiot, but this might be the reason for the sparse responses.
 
seabeagle":25uoyaau said:
Also I found out why this thread is so sparse. A call to me today revealed that several of the resident experts (which will remain unnamed) on the site are boycotting and giving me the silent treatment. It's sad because their knowledge would only improve the thread. At age 38, I hate to be the only adult in the room.
Click to expand...

seabeagle-

I'm unaware of any "boycott" (!)

However, it may just be that many or most of us are more familiar with the CD-22 and larger boats and motors that are more common, and speculating on what would work on a CD-16 with a smaller motor is out of our familiarity range.

Good luck with your prop quest! It's always a guessing game, even with good information and knowledge, and is always somewhat of a hit-and-miss experiment into the unknown and mysterious! :lol:

Joe. :teeth :thup
 
seabeagle":1e0vynm8 said:
I stopped by the Dory dealer again today and now he thinks 11 pitch might work. Pretty soon speculation might be more accurate.
Click to expand...

You have no idea the agony I experienced with my 19 foot closed bow bayliner in selecting a prop for my "new" 140 OMC. It was like hell......Nobody had any clue. And that included guys who should know....Props can be tough.
 
That is what I was telling you earlier. It usually requires 2 degrees less pitch when going from a 3 blate to a 4 blade. That is generally always the starting point for the change. Then you can get a prop shop to fine tune the pitch for optimum performance.
 
OK, final test. I put on a Solas 4 blade 11.1X11 and have decent holeshot with 24.5 mph at 5800 rpm. I've ran two days of tests, one on Lake St. Clair in light chop and wind and the other in local lake with calm conditions. So far I haven't had any ventilation and if sound of the motor means anything, it sounds firmly planted in the water. I guess 24.5 mph is my top possible speed with the 50 horse engine and the weight I carry. And even though my top speed and rpm's are nearly the same, I did gain a slightly better holeshot with the extra blade.
 
Back
Top