Solving the Lake Powell BF130 /150 Problem

[Wandering Sagebrush]

[jkidd]

My CD22 with a Suzuki DF115 EFI 5500 RPMS 28 MPH with a Solas SS 13-7/8 X 17 pitch. It drops 22 MPH when I'm towing the Mokai. WOT is 6000 RPM.

[jlastofka]

I also agree that Powell affects the 22's, but not as much. Apparently the 22's as most people have them set up have a little more margin above minimum planing power than the 25's do.

My 22 with the EFI Honda 90 drops about 500 rpm and probably over 5 mph, but I didn't really check that. I just cruised along at 4400 rpm and 17 to 18 mph and got 3.3 mpg. I have the Honda 15 dia x 13.5 pitch prop. I'd like to buy a spare, but can't decide what to get. Perhaps a little less pitch in case I go to Lake Tahoe or someplace else really high?

My boat was heavy for a single person boat. Kayak, fishing junk, too much food and water, firewood, etc. Plus I have the kicker with power tilt/trim. It's heavy.

3700 ft means a lot less oxygen than sea level. You're going to lose power, no way around it. The question is whether it will be just a drop in top end speed but still good planing performance, in which case you'll say "I really didn't notice it much", or a drop below planing speed, which is another matter entirely.

So, this is a sort-of-hijacked thread. At least we're on a closely related topic. I'm going to go searching for Lake Tahoe prop information, now that I've thought of it.

Jeff

[jkidd]

Jeff do you maybe have the diameter and pitch switched?

If I take just my hull weight and divide it by my HP I see some interesting results.

22 with 90 21.3 lbs per HP
22 with 115 16.7 lbs per HP
25 with 130 27.7 lbs per HP
25 with 150 24.0 lbs per HP
25 with 175 20.5 lbs per HP
25 with 200 18.0 lbs per HP

The CD25 with a 130 is probably under powered at 3700 feet. The best you could do is go down in pitch till you get to as close to WOT as you can get.

I read out on the web that it was illegal for the manufactures to make changes to there motors because of emission standards. My comment earlier about changing the chip in the ECM was because I know Polaris had a racing chip that you could get for there PWC, but you had to sign a paper stating that you were going to race with it. If you were to lose 10 percent of your HP at 3700 feet then the chip, if there was one available would just get you back to full HP. I don't know if one exists. Did they stop racing boats? I don't follow that. I know they do make chips for the Honda Civic which is where the motor comes from. Don't know if they changed it for the marine market.


Pat if you sell the 130 HP and buy a 200 HP the pounds per HP is 18.0
Is the 130 and 150 the same motor. Like Suzukis DF90 and DF115 (old not new) If they are can you change the chip. Just a few question to throw out there.

[journey on]

Those are interesting numbers: #/HP. And for the 25, they're probably even worse, because the hull weight is so low. I don't know exactly what weight you used, but add the motor, refridge and all the cruising gear and I'll bet the #/HP is even worse, with a bigger increase than for a loaded 22.

I figure I cruise with ~7000# which gives a #/HP ratio of 47. Try that for economy and speed. That includes full water and fuel, stuff for 3 mos, additional batteries, etc, etc.

The 130 is not the same engine as the 135/150. For example the 150 is actually lighter, has a different gear ratio, etc. The factory recommended the 135, glad I got the 150. A bigger Honda would go from a 4 to a V-6.

Boris

[dotnmarty]

For some reason this thread reminds me of the old joke "Death, nature's way of telling you to slow down". I've only been to Lake Powell once, years ago, when the kids were small. But I do remember it as an overwhelmingly beautiful, almost spiritual place, where, perhaps, one is encouraged to slow down.

[Wandering Sagebrush]

[jlastofka]

oops. I guess I did reverse the numbers. My stock Honda 90 prop would be 13.5 diameter and 15 pitch, wouldn't it? I had written it down wrong in my notes.

I remember the Wefings man said (I think) a stainless 13.375 x 14 three blade was the ideal setup. Maybe I'll get one of those and see which I like best and keep the other for a spare.

I'm also thinking about a Permatrim. I run with a lot of trim tab down (more than half) and I think the engine plate might be a more efficient way to get that lift.

Jeff

[jkidd]

Boris
I just used the bare hull weight from the factory, they say 3602 lbs for the 25 and 1925 lbs for the 22. I know all the other goodies will have an effect also. I figure that the bare hull weight would let me see how just the motor hp and hull weight were equal to each other. Were the CD22 with a 115 HP ends up you would have to put a 200 HP on the CD25 to get the power to weight ratio close. Then when you start adding all the goodies you would be out of wack again. With my boat I can run the same prop at sea level that I do at Lake Powell. I do see a small change but not much. When I go above 6000 feet is when I see a big change. There I could drop down a pitch size. However the boat still planes and gas consumption is still ok.

[sportner]

There is a service bulletin on Honda 150's with serial numbers between 1000001 thru 1101713 that says performance is effected at higher elevations. My serial number falls in this range and my Honda tech here in Chinook is ordering the new electronic command module that hopefully is covered under warranty. I have yet to take out our boat at sea level since our return from Lake Powell but it ran fine before we left. Our performance at Powell was 3200 rpms and 9.5 mph with poor economy, we kept it at 2500 rpm and 7.8 mph and got about 2 mpg.
I will post after we go out for crab in the next few days and after we get the new ECM.

[Pat Anderson]

We ran with Russ and Toni a lot, same speed, and our computed fuel economy for the whole time we were there was 3.2 miles per gallon...going S...L....O...W, but no complaints, it was great! I will check our serial number against those below and ask West Coast Marine. We also will find ourselves a 14 x 13 prop for the next Powell trip!

[thataway]

My C Dory 22 was about 4000 lbs ready to go, the 25 was close to 6,000 lbs ready to go. To back up Boris's comments on the Honda engines:
The 130 and 115 share the same block--at 137 cu inches, 505 lbs Long Shaft, 2.00:1 ratio.

The 135/150 share the same block at 144 cu inches, 485 lbs 2.14:1 gear ratio.

To get the really fuel effecient speed on the 25 you would have to drop down to 6.1 knots, and for the 22: 5.6 knots. If you are running at 9 to 10 knots this is probably one of the most ineffecient speeds you can go at.

The Permatrim will help by putting the bow down in chop. It will also give a slightly lower planing speed, and up on a plane faster.

Our experience on Powell, on the first trip, we had a seal level SS Prop, and no Permatrim. We could barely get on a plane, and were not getting WOT RPM. The second trip. we had a lower pitch aluminum prop, the Permatrim and perhaps slightly lighter, and were on a plane all of the time.

[tpbrady]

Bob,

At 10 knots in my 22 I can be on step however to get there I have to get up on step at a higher speed and then back off the throttle while adjusting trim tabs and motor. I normally end up with about 1/3 tabs with motor up about 1/3 on Honda trim guage. On step with the new EFI 90 Honda at 10 knots is actually pretty efficient, over 4 mpg on fuel flow and actual consumption using the Quicksilver 14 pitch 3 blade prop. I found this cruise mode first with a Permatrim and then removed it and could still get comparable efficiency with just a little more trim tab and moving a heavy cooler foward to between the helm and passenger seat.

[sportner]

For anyone with Honda 150's with serial numbers between 1000001 thru 1101713, Honda service bulletin # 46 states that performance may be effected at higher elevations.

[journey on]

According to a San Diego Honda dealer, Boat Depot, Inc, the serial numbers are up to 1100713. This would include anyone who bought their boats/motor in 2005.

Journey On's motor qualifies, and I think Pat A. and Anna Leigh bought their boats about the same thyme.

Boris