Prop Pitch for BF90 on a 19angler

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saltspring

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Mar 24, 2007
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C Dory Year
2007
C Dory Model
19 Angler
Vessel Name
Eva-C
Does anyone have suggestions or data on what size and pitch might be appropriate for a Honda 90 on a 19 angler. The one I have on there now is a 13 1/4 X 17 and it seems as if the RPMs are low at full throttle.

Thoughts appreciated.

Philip
 
saltspring":ov4h2uvc said:
Does anyone have suggestions or data on what size and pitch might be appropriate for a Honda 90 on a 19 angler. The one I have on there now is a 13 1/4 X 17 and it seems as if the RPMs are low at full throttle.

Thoughts appreciated.

Philip
Click to expand...

Back in the Honda 90 days with a 17" on the 22' I could only turn 5200rpm switched to a 15" and was able to make the recommended 6000rpm @ WOT. :mrgreen: :beer
 
What are the RPM, what is the load carried and what is the elevation at what the boat is run? Also is the prop excessively cupped or does it have excessive rake to the blades also what is the prop material? You would ideally want the engine to turn up 6000 RPM with a light load at sea level. As you go up every 3700 feet you need to drop the pitch two inches. If for some reason you are not getting the full RPM (with the boat trimmed properly)--then drop down the pitch by at least 2" and expect to get 400 more RPM.
We had a 90 hp Evinrude on the CD 22 and carried 17", 15" and 13" props. On the 25 we have gone to an adjustable composite for our back up and high altitude props, as well as the SS standard prop.
 
thataway":iy5z5vrm said:
What are the RPM, what is the load carried and what is the elevation at what the boat is run? Also is the prop excessively cupped or does it have excessive rake to the blades also what is the prop material?
Click to expand...

The boat is at sea level or almost, with 2 adults, almost no fuel and 30 lbs of gear I was getting a little over 4K rpm at full throttle. The prop is a honda alum 3-blade.
 
Something is definately wrong. It is a new boat, so I assume that there is no fouling on the bottom. The load is relitatively light. Even dropping down 4" in prop pitch would not bring the RPM up. I wonder about trim and motor position, or something in the linkage which is not allowing full throttle position.

I would have the dealer check out the boat for starters--he should also have a variety of props you can try, but the stock Honda prop should be fine. (My recollection is that the lower unit gear ratio on the Hondas and Evinrudes are approximately the same).
 
The final piece of information needed is the speed the boat can attain at full throttle and at what RPM indicated. it is possible that the tach is not reading correctly. My Honda 90 on a 22' cruiser gets about 30 mph at full throttle and about 5900-6000 RPM. My prop is the Honda (Solas) 4 blade 15" pitch. The tach has DIP switches that adjust the indicated RPM based upon the number of poles on the alternator of the engine. There is an earlier thread that explains this and the correct setting on the back of the tach. It seems that a 17" pitch shouldn't be at 4000 RPM but rather about 5500 or so. My Honda is a 2006, and is the carburetted version, so a 2007 would be different due to the new gear ratio.
 
We have a new EFI Honda 90 on a 22 Cruiser . Its the one that was on boattest.com . It has a Honda/Solas 15 P stainless prop and is propped about as good as it can get . I was with the Honda techs at Miami and they didnt even try to reprop as they didnt think it could be improved. At one point we hit 36 M.P.H. with light fuel load and 2 people aboard . 33 MPH with5/8 fuel and 2 people with testing and camera gear. RPMs near 6.1k . http://www.boattest.com/boats/1455/test_results.aspx
17" is too much pitch for either an old or new 90 Honda in my experience , they seem to like 13s and 15s. Hondas like to run up at the top end of their RPM range.Check the tach and make sure you are trimming up when checking RPMs.
Marc
 
Philip,
Another resource is the Honda Website. There's a 22 test with a 90 turning a 13 1/4 X 17 X 3 that shows 32.9 MPH at 5400 RPM WOT. There's another test with a 13 1/4 X 18 X 3 that shows 28.5 MPH at 5100 RPM WOT, so bigger is definitely not better. It seems to me that your prop should be OK on a 19 assuming they plane about as easy as a 22, which might be incorrect, but I'd start by looking at the trim, the tach and the engine. You should be getting way north of 4K RPM WOT. Check out their prop tests at the link below.

http://www.honda-marine.com/performancetest.aspx#330

Good luck!

Mike
 
Notayot":3gvo9kez said:
The final piece of information needed is the speed the boat can attain at full throttle and at what RPM indicated. it is possible that the tach is not reading correctly. My Honda 90 on a 22' cruiser gets about 30 mph at full throttle and about 5900-6000 RPM. .
Click to expand...

Thanks for all the help, I really appreciate it from everyone. The motor is the 2006 carb version. I took the boat out again today to validate my data points and I am inclined to think that the tac may be set up wrong. Here is the data for wide open:

Tac reads 3800 Rpm
Speed (GPS) 33 MPH

Since the 19 is pretty stern heavy I use the trim tabs in 40 position when on plane. I believe the motor was trimmed correctly. I did move it around a little with no dramatic effect on the RPM.

So...should I expect much more speed than this? Does the prop pitch seem that far off?
 
Philip,
Based on the Honda prop tests your WOT speed sounds about right. It sounds to me like your tach isn't reading correctly. Honda rates your motor at 90 HP@ 5500 RPM so I don't see much point in selecting a prop that will let the motor turn 6000 RPM unless you need a smaller prop for heavier loads or better acceleration. I've never seen a HP verses RPM chart for any of the Hondas so I don't know if extra revs past 5500 actually improve the power output.

Good luck with your tach!

Mike
 
I agree, I suspect the tach is improperly set. The speed is about what you will expect in the mid 5000 range. There may be dip switches on the back--Check with the dealer
 
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