Solving the Lake Powell BF130 /150 Problem

Pat Anderson

It seems that every CD25 with a BF130 / 150 experiences the same problem on Lake Powell - terrible performance, the CD25 becomes a 7 knot trawler (not necessarily a bad thing on Lake Powell!). If you put the hammer down, you might get up to 12 or 14 knots burning 12 or 14 gallons per hour! The BF40 / 50 / 90s seem to be little affected or not affected at all. So it makes it real hard for the CD25s to run with the CD22s.

I propped down to my original Honda prop, a SS 14.5 x 15, which spins up way too many RPMs and goes nowhere at sea level, which worked way better than my regular sea level prop, a Quicksilver 15.5 x 15, which is a wonderful performer at sea level. Still way too much pitch for Lake Powell I guess.

This year, Ken on Woodduck apparently solved the Lake Powell dilemma - with a 15 x 13.5 prop. He reported being able to achieve 20 knots with normal fuel consumption. I looked online and I can get an aluminum prop, either 14 x 13 or 16 x 13, for about $140 - $160, I am thinking the 16 x 13 might be the one...thoughts?

Another potential solution per Russ on Traveler might be that certain BF150s (serial number dependent) might benefit from a different ECM (electonic control module) - Traveler was really affected, so he checked by phone with his certified Honda tech back in Chinook, WA, and found out there was a bulletin on this from Honda. So I will check into this as well.

If anybody has any other thoughts on how to maximize high altitude performance on the BF 130 / 150s, I am sure several of us would be anxious to here them!

jkidd · Posted: Mon Sep 28, 2009 10:42 pm Post subject:

Pat

Are you carbureted or fuel injected?

Pat Anderson · Posted: Tue Sep 29, 2009 12:47 am Post subject:

The BF130 / 150s are "EFI," which stands for electronic fuel injection, which I assume accounts for the need for the "ECM" (electronic control module).

jkidd · Posted: Tue Sep 29, 2009 1:05 am Post subject:

I guess that would mean just finding the right prop so you can get to WOT and maybe there are some after market chips for the ECM. I bought a SS for my 22 and after I ran it found that there wasn't much difference between SS and Aluminum on the 22. Some of the prop shops around here will rent props so you can try a few. Maybe a smaller diameter with the same pitch or a four blade. Maybe someone with a 25 and the honda 130 will chime in with just the right combination for 3700 feet altitude.

Sea Wolf · Posted: Tue Sep 29, 2009 2:48 am Post subject:

Pat-

Surprised you haven't gotten more responses on this.

Bob (Thataway) should be able to give you some good advice, since he's been there several times, the last one at least with his 25 Frequent Sea just before he turned it over to the new owners.

You're fighting a couple of problems on Lake Powell, the elevation (3700') for one, and heavy loading for a long cruise, for another.

The available oxygen in the air drops with the density of the air, which is about 3% per 1000 feet. The first 1000 isn't too noticeable, but one definitely sees the 3% loss in power each 1000 feet after that. At 3700 feet, there should be at least an 8% loss from the elevation change above the first 1000 feet.

Compounding the problem is the heavy loading. Faced with an over-proped situation, the motor can't begin to get into it's most efficient operating range.

The EFI/ECM should make at least some adjustment for the drop in atmospheric pressure and lean out the mixture, but the engine is lugged down so much with the over-pitched prop that it can't really make up the differences and adjust.

Dropping from a 15 inch pitch prop to a 13 would indeed seem like the first and most logical choice. 13/15 =.866 or 86.7%, which would accommodate the 8% loss in power due to elevation, and 5% more due to over loading.

The only question would be is if this is enough adjustment, considering all the people, food, gear, fuel, and gas on board. (?)

Unfortunately, the props seem to come mostly in 2 inch increments, so going down to an 11 inch pitch would be only logical if someone else was already making it work, or if the 13 wasn't enough.

Instead, I'd stay with a drop to a 13, and keep the diameter limited, and see if the slip allowed by the standard diameter would also help to accommodate the situation. (Slip is always around, and can be your friend, in many situations, with a prop.)

Also, keep in mind the boat gets lighter as the days progress, and you have to accommodate a range of loads, and you may also want to use this same prop at even higher elevations, maybe even twice or more as high in elevation.

I wouldn't bother to mess with the ECM, either with a different chip or re-programming it. 3700 feet isn't that big a difference, and changing the ECM control would be a very easy way to have engine problems that cost a lot of $$$, and wouldn't be viewed kindly by the folks at Honda, should they become involved.

If I were you, I'd just buy a moderate sized (diameter) 13 inch pitched three-blade aluminum prop and give it a go and see what happens.

See you and Patty in January at the Boat Show and C-Brat Shindig!

Joe. Teeth

Pat Anderson · Posted: Tue Sep 29, 2009 8:41 am Post subject:

Thanks for your thoughts, Joe. What are your thoughts on the diameter? Current props are 15.5 (Quicksilver) and 14.5 (Honda) diameter, and all the improvement of the Honda over the Quicksilver at Lake Powell must come from the 1" drop in diamter, since the pitch is the same. Choices for 13 pitch that I could find are 14 or 16 diameter. How significant is that, and on which side of 15 should I land for the new 13 pitch prop?

As to responses, people are interested in what they are interested in I guess. I am also amazed that there has been no post for so long in the Lake Powell thread itself. And check out this year's pix! Anyway, I find myself less and less interested daily in many of the topics, so I skip any number of threads. Perhaps I shouldn't, because a lot of the most interesting discussion is when some mundane thread gets highjacked! Maybe we should work on highjacking more threads!

Nunya · Posted: Tue Sep 29, 2009 11:46 am Post subject:

I run a 15.5 x 13 on my 25. Works out well. You need the larger diameter to push a heavy load.
Just completed a 1131 mile trip on the Yukon River in Western Alaska dealing with rough water, sand bars and fuel availabilty, among other things....... so no I'm not particularly interersted in a Lake Powell thread.

Sea Wolf · Posted: Tue Sep 29, 2009 11:57 am Post subject:

Doryman · Posted: Tue Sep 29, 2009 2:05 pm Post subject:

A website like this is an organic entity, which grows toward the food (activity) and does not respond well to management (pruning). I see it as part of the price we pay for the freedom we enjoy here.

When I first joined Bill and I discussed a C-Brats FAQ but nothing ever came of it. Maybe now is the time for a group effort to develop one?

One of the reasons there are so many new threads covering old topics is that the search facility of the phpBB software is pretty sucky. But another reason is that many of the topics we search for use words that have multiple uses, all of which produce hits.

Just some random, off topic Mr. Green

thoughts.

Warren

Wefings · Posted: Tue Sep 29, 2009 2:14 pm Post subject:

Pat is a word with multiple uses ...........
Marc

DaveS · Posted: Tue Sep 29, 2009 4:46 pm Post subject:

Pat Anderson · Posted: Tue Sep 29, 2009 9:54 pm Post subject:

Joe - not far behind, 4,981 (well, actually this one makes 4,982...). Shall I stay up all night and post about 20 more to crack the magic 5,000?

So, anyway, yes, a thread on highjacking protocol would be good.

thataway · Posted: Tue Sep 29, 2009 11:18 pm Post subject:

We had what I would consider marginal performance at our first trip to Powell. The second trip we had added the Permatrim, and it made all of the difference. We were able to run at our "normal cruising speed" of 17 mph (This is with the 130 --the 135/150 engines are a bit more powerful)
The boat was pretty well loaded, with full water, fuel, extra water, air conditioner and generator, as well as much of our cruising gear. The dinghy was left off on the last trip.

I think that we had kept the same SS prop on, but obtained a 3 blade aluminum prop which was slightly lower pitch.

CAVU · Posted: Wed Sep 30, 2009 7:43 am Post subject:

Pat,
We had this discussion during the Lake Powell trip. It seems to me that your problems may not be the prop. Most of the 22's reported little or no change in performance. I got exactly the same speed and rpm's I get at sea level or home at 2400 feet elevation. If there were any differences it was very minor. If this is true for a 22, logically I can't imagine why it would change for a 25. Maybe the computer controlled fuel injected engines are not compensating for the altitude correctly? Mystery to me.

NewMoon · Posted: Wed Sep 30, 2009 9:55 am Post subject:

I can't remember the numbers, but for our 22 (always loaded for cruising) with a 90hp Yamaha we had three different props: one for sea level, one for Lake Powell (3,700 feet), and yet another with even flatter pitch for Flaming Gorge (6,000 feet) and Yellowstone Lake.

They were all the same diameter. The two we used the most (sea level and Lake Powell) were stainless - more efficient due to thinner blades. We experimented a lot, and found that having the right prop for those three very different elevations made tons of difference.