Bertram 25 express update, and repower questions.

[Howesounder]

Used a putty knife to dig through 6" of primordial ooze, then a pressure washer with near boiling hot water, and got to work on the express. Hot water pressure washer worked fantastic. Pulled the recently added gas tanks as the straps holding it in place waer all pulled out. This thing must have spent some time at the 50 mph the pair of 225 2 strokes were reported to make this thing go, to rip out the tank strapping. Having said that, they were poorly secured.

I have purchased and mounted a 250f yamaha 4 stroke with 3100 hours, and it seems to run fine, but I only whent with this power unit until the basic package proves to be the pocket cruiser I am looking for. Longer term, I am not nuts about being in open westcoast water with a single engine of that advanced hours. (Will have a hond 50 kicker, and I hope it will push the boat at 7 knots.

I want this boat to do 20 knots. I won't be asking for any more speed than that as every time you double the speed, the fuel burn increases by about 8 times. I used the victoria prop calculator, and fed in the boat and engine data using the previous owners 2 x 225 hp and 50 mph, and sure enough the calculator suggested 44 knots top speed, so this is promising. Then I reduce the number of engines by one and change the hp to 250, dropping the weight by 600 lbs at the same time and the calculator comes up with 34 knots as a top speed. It suggests that I will be drawing 80 hp to do my desired 20 knots. This seems low to me, but I then drop the weight a bit more and try again with my near new 150 suzuki, that I would have loved to have used, but seemed too small, and the calculator came up with a 26 knot top speed.........still enough above my design speed to allow me to make a 20 knot cruise do-able with a 150.

So, if the calculator has it right at the pair of 225s pushing the boat to 44 knots, does it also have it right that a single 250 would do 34 knots? (30 seems more like it to me) Then what of a single 150 hp engine? Will that extra lack of weight in the stern, and a single 150 possibly allow a 20 knot cruise? I really like the suzuki. I had a DF 140 on my 19 foot centre consul, and it put up with many years of constant abuse. We ripped four propellers off it in one day in a river at the end of the Bute inlet for instance, and the engine only died when it snapped of the boat when crashing through steep 8 foot seas one day.

Steve

[captbone]

There is a 25ft Bertram Hardtop with a single 150hp Evinrude Ficht is Barbados. He got 30mph as his top end. I have a couple of pictures. He built the boat light weight and used a bracket for the engine .

I think depending on how you use the boat it could work fine. I was able to keep my Bertram on a plane down to 12-14 mph using tabs and doel fins on the engine. The boat ran level and was on plane. The engine was only turning 3000 rpm. I dont see why a 150hp swinging a 16x13 prop would not be able to cruise at 18-20mph with a top end of 28mph.

An engine does not know what kind of boat it is on. It can be on a 50ft Barge swinging a 7 pitch prop doing 4mph at 4000rpm or a 15ft tunnel hull swinging a 27pitch prop doing 50mph at 4000rpm. The important part is that you dont push the engine to get the mph that you want instead accepting that 4000rpm maybe 15mph or it maybe 20mph.

Since you already that the 250hp Yamaha, I would say run it and see for yourself. I found these hulls dont need a lot of horsepower. They originally came with twin 110hps.

[Howesounder]

Thanks for that Captbone. Sounds like on the heavier express, set up for overnighting, hot water heater etc (6 gallon water heater using a 600 watt 12 volt element, and a relay that will only allow it to heat when the engine is running) the boat will be substantially heavier, and the 150 would be a waste of time. I shall start looking for a lower hours 250. What are your thoughts on a kicker? I have a 50 hp Honda available at 215 lbs, and a 25 hp tohatsu that clocks in at 157 lbs. My thinking has been that with the only slightly heavier 50, and a high thrust prop, that the boat might actually be safer in snotty seas in a breakdown condition, and be able to make decent ground with the 50, where the 25 might have a tough time keeping a course etc. thinking maybe 8 knots with the 50 where I might be stuck at 4-5 with a 25

I would set up either to steer off the main engine

Steve

[captbone]

Go with the 50hp. The exta weight in the stern is a good thing believe it or not on these hulls with outboards. I think it will be just fine. Post up some pictures.

[CamB25]

Why not make use of the twin engine bracket? Install a couple of small 4 strokes...anything with a 25" shaft. Go faster when you want to, putt around on a single.

[captbone]

Good advice. Twin 115hp would be ideal if money is no object.

[Howesounder]

Yep, I get the twin idea. Money is a bit of a problem. Right now I just want to get it on the water, and learn its suitability to my purpose. 20 knots so I can get where I want at a somewhat reasonable fuel burn. Hot water, and a shower, with a small BBQ and icebox. Couple of very nice deck chairs stored below where the engines used to be, and there is my pocket cruiser. Good for weekends and 3-4 days out at a time them mayby find a hotel for a night, clean up, grub up and get going again. I want to be able to go anywhere I want including outside water. Love the look of the flybridge, but like being close to the lines when fishing, and having all people on the same level when cruising, so hence the less good looking sister......the express. (I actually like the look, looks mean to me)

So if the boat handles the west coast water the way I hope, and the fuel burn is the 7-8 @20 knots I hope for, then I will start looking for long term power. (This engine came with a 3 blade ss 17 inch prop and controls all for $3500, but has 3100 hours) I have this perception that you loose efficiency with twin engines. Cost per mile to run a twin 115 hp set up would be about 1.15 of a single 230 hp motor at the same speed. That sound about right? If so that is too much loss for me. I lean towards a single main, and a healthy kicker that can do trolling, and puttering speeds, and also works as a generator if I need to charge up the batteries. I did some reading on the 250 F and there seems to be people getting up to 6000 hours from them. With a 50 hp kicker I should be safe, if bored, when this one fails. Then because of budget, I would start looking for another 250f that someone is trading out for bigger, better fly by wire etc.

Steve

[Yannis]

Hot water, and a shower, with a small BBQ and icebox.

I was thinking a lot about a water heater too, although in Canada it should be more of a necessity.
Next year I'll probably install one too but not electric. I found that those speedy gas ones are very practical. I carry a 5kg gas bottle anyway for my cooking range. The thing is to find a place to hang it, which in the 25 might be yet another puzzle.
One good thing is they don't have a permanent pilot flame on anymore; instead they kick in with a spark from two batteries inside the heater skin. On the other hand, there is an open flame when the heater operates. And with so much gasoline under your feet for the outboard, this might be a thing to consider.

[Rocket]

Steve, as far as the kicker is concerned, have you considered kickers? I have always thought it would be great to have two 9.9 or two 15 Hp kickers that you would use whenever running at displacement speeds. You would have the effeciency of a big single and the control of twins when trolling or docking. You would have to think through the controls and steering, it's just a concept but I think it would be doable and have some real advantages.

[John Swick]

250 f ? (as in 250hp Yamaha outboard) getting 6000hrs of running time ??
Good luck with that.

But 250hp is adequate power to push a B25 to its design specs.
I have a B25 Bahia Mar with a Volvo 375hp d/p I/o.
It's sweet spot (as far as I'm concerned) is 25 - 35 kts.
After that, there's not much boat in the water and the ride gets progressively less stable from there.

[CamB25]

What is the displacement speed of the hull? Fuel economy will drop like a rock from that point until you are on plane. It's a planning hull...going to be more efficient on plane than anywhere above wake speed. Seems like you are trying to turn the Bert into for a semi-displacement hull boat. I'm not sure that is possible or practical.

[Howesounder]

I seem to be getting reports that the 25 will plane at speeds as low as 12 knots, so with the lighter single 250 outboard, I would hope to be able to have 12 as a minimum planing speed. Used doel fins etc. if required. I used a Davis plate on a 14 foot four winns fling jet boat I converted to outboard. Had a 120 hp failed jet, I installed a 25 hp outboard. Love the dam boat but it would not plane with two people, or at least one had to get up front and wait 30 seconds each time. Even with one person it was sort of don't slow down or you were off plane. With the Davis plate it planes at just 10 knots, and will plane with 3 people. Does 23 knots wide open! Which is where it lives. I am not looking to go displacement speeds except for bumming around exploring. 20 knots is the compromise speed I am looking for to give the best combination of distance traveled in a day and gas mileage. My "read" so far is that 20 knots is far enough above the "just planing" speed, that I will not be in a semi displacement "plow" at even 16-18 knots. We get some very steep snotty seas in quite a number of areas of the coast here that are a real bugger to deal with. I have been from almost Prince rupert to Seattle in my 19 foot welded aluminum boat with 150 4 stroke and my choice has always seemed to either set the autopilot do 20-30 and hold on for dear life, or slow down to as little as 8 knots, and even at that endure a terrible pounding. So this boat I am hoping will take those steep snotty seas, and do 16-22 in most anything.

2 kickers, I had not considderd Rocket. I have a 50 Honda "in stock" so will be trying that one out to see how it does. I want to be able to point wherever the hell I want in most any conditions with the kicker, so that wherever I am ,.....I can make it home safely if not quickly. With an undersized kicker my experience has been that in a blow you don't make much headway against the wind, or worse you keep getting blown off the wind. So I am going to go with the advise I got here and go with the 50 rather than
my other 25 Tohatsu.

The hot water heater is interesting. The yamaha has a 70 amp alternator. They make a 600 watt (50 amps @ 12 volts) 12 volt water heater element for solar situations that screws right in. So I have a big solenoid that closes contacts to the water heater only when the engine is running. So when running, and switched on I can count on 6 gallons of hot water at the end of the day. Cabin heating, I am not as concerned about, but would be nice


The 6000 hour thing is what I got from a few Google searches doing such high teck searches as "yamaha for stroke engine life expectancy" or "how many hours can I expect to get from....." this engine at least gets me the right prop, a set of controls, and a lottery on how many hours it has left. Could do a power head at some point but I think buying another used 500-750 hour engine makes a bit more sense if the boat proves to work out right for me.


Steve