bertram31.com

Hi all,

Brand new member here; just got my 31 a couple months ago. About six months ago My fiance and I wanted a boat that was good for diving, that we could take to the Bahamas and had a nice cockpit so we went to a local yard. We found a 1970 with 454 Seamaxx's that has a closed cooling system and a tuna tower and picked it up for 40k. I've looked through its papers and maybe someone here is familiar with it; it was owned by Capitan Harry Vernon (Miami/Keys) from the 90's to early 2000's, the boat name was Vernon, then it was the Barefoot (Jupiter Florida) est 2008, then the Vienna (not sure when), and at the time of my purchase is the Teppi (transom says St. Augustine but I bought it in Lighthouse point).

We've already replaced both raw water pumps and had custom hoses made up as well as a coolant flush and oil change, we still have rust on the spark plugs in cylinder's 5 and 7 on the starboard side and a heat soak issue with the port engine (over 2800 RPM), My starboard trans/(or maybe shaft is bent) at idle has a constant knock and under power, even slightly it goes away (sent a video to the trans manufacturer and he said could be normal). We've put down lot's of new paint in the cockpit, as well as rewiring and making new headliners, just installed an inhull transducer and am installing a new plotter today and its coming out in a month for the bottom, struts, rudders, shafts and props (to be balanced). Also we tried our hand at some faux teak on the bulkhead. Lots more work to be done but we are happy.

Happy to be here and happy new owners looking forward to any advice that you guys want to share!

https://photos.app.goo.gl/arFXms5Rn8ukgkUSA

https://photos.app.goo.gl/sHGUzZ5UB7xUMEvt7

https://photos.app.goo.gl/nWL6vR754w4KU6sB8

https://photos.app.goo.gl/jMNht1nBcBuwYj488

Congratulations and welcome aboard! Great looking boat! Some of the more experienced members will surely chime in but one quick observation (happened to me also) - the trans knock is most likely a slight miss in the engine and not the transmission. Suggest a tune up on that engine or a compression check to verify but that is very typical of a low speed engine miss. The miss causes the clutch plates to slap or whatever the term is. Once you accelerate the higher rpm's solves the problem.

Good luck with here.....

Welcome to the sandbox! You will find this to be a great source of knowledge. Best of luck with you boat she is looking good.

Great dive boat. If you will be doing a lot of diving, consider a swim platform. I fought a ladder for years and the platform made all the difference. If you add one, make sure it has lots of slats to keep waves from pounding the underside. I made mine out of fiberglass grating. Also when you balance your props and shafts, I suggest having the gearbox coupling, shaft coupling and shafts checked at the same machine shop. Both of my shaft couplings and one of my gearbox couplings had to be refaced.
--Marshall

I agree with Mark on the knock at low speed that goes away once you power up some. A miss will definitely do that. For me it was almost always bad wires. Trick from my mechanic friend was to lift engine hatches when dark out…it looked like a lightening show with wires shorting to the block.

Too slow an idle made it worse. To fish bass I kept under 650 in gear and any miss
Or not smooth running sounded awfull.



Welcome aboard, it’s a great boat, you” love it

Congrats and welcome aboard. If you're going to be running your boat back and forth to the Bahamas then you're going to want to make sure the engines are rock solid. Thats not a place you want where you want to break down.

Are you in Florida?

If you don’t know Capt Harry Vernon III, owns a tackle shop and is a regular guest on George Poveromos world of salt water fishing.

Congrats on the boat and enjoy her in good health.

Thank you for all the suggestions. I replaced the heat exchanger gaskets on the port side of the starboard engine (where the rust on the plugs was) and there was a little water getting in the elbow. It didn't steam as much but still struggles to get up on plane, its just like all the power is not there when you hammer down. I am pretty sure it was missing on 5 and 7 because of the water so I was a little disappointed to still hear, what I think is a shaft knock when I took it out for some testing today. Still lots more to go through but I am going to sift through the forum for some wisdom.

Re. Cpt. Vernon I did not know that I am going to check it out. I am in Jupiter, FL so if anyone is around here it would be fun to meet up.

TwoCoconuts wrote: ↑Jul 5th, '21, 17:45 Thank you for all the suggestions. I replaced the heat exchanger gaskets on the port side of the starboard engine (where the rust on the plugs was) and there was a little water getting in the elbow. It didn't steam as much but still struggles to get up on plane, its just like all the power is not there when you hammer down. I am pretty sure it was missing on 5 and 7 because of the water so I was a little disappointed to still hear, what I think is a shaft knock when I took it out for some testing today. Still lots more to go through but I am going to sift through the forum for some wisdom.

Re. Cpt. Vernon I did not know that I am going to check it out. I am in Jupiter, FL so if anyone is around here it would be fun to meet up.

I'm located just south of you in N. Palm. I don't have my B31 there yet as I'm trying to get her repowered. There is a lot of wisdom on this forum and folks are happy to answer questions if you ask. The problem is knowing what to ask!

Sometimes over a couple of beers I'll be happy to tell you what I've learned.

Twococonuts

I have to agree with Mark and Carl. Our boat had transmission noises at idle from the time it was new. Seems that was an issue with the Borg Warners. Not sure what model transmission you are running.

My transmissions made some noise too. Always did make more in reverse but ran smooth.

If you have counter rotating engines, you have two different transmissions that are running 'in sync'. If you have two engines that spin the same way, then you have two identical transmissions. One is running in reverse while the other is running forward. There are two things that happen. One is that at idle, the one that's running in reverse is going to make a little more noise than the other one. Second is that since they are identical units, they can never be in exactly the same ratio while one is in reverse. So if you have electronic tach's and you sync by ear, your rpm's will not be the same. Both are normal.

What make transmissions? It could be as simple as a broken spring in the flex plate. I had a friend who had Hurth 630's(?) that sounded like it had a handful of gravel in them at low speed. They naturally sound like that.

Just documenting for the purpose of anyone reading this down the road...the transmission noise was due to a misfire caused by a bad injector and water in the #5 cylinder. The steaming was caused by overheating elbows due to lack of flow from clogged inlet thru hulls. The issue with getting on plane was resolved by flowing all injectors and replacing the inlet thru hulls (probably could have just been cleaned). I added new props after the fact 18x18 3 blades (had 17x17 3 blades before) and now the boat planes at 2400rpm

I assume Borg Warner Transmissions. If the engines shake a little you will get a rattle in the transmission when it is not engaged. We had that with a cold start up when we had the Big Blocks. Just of quirk of those transmissions.

How much weight are you carrying? Planning at 2400 with the 454's seems a little high. We used to be able to hold a plane at 1600 RPM's running 18X19 3 Blade.

I have to say that was with a light boat. Full fuel but not loaded down with equipment. Going offshore carrying ice, extra fuel, 5 guys, etc. We still go up on a plane at less than 1800 RPM's.

Are you hitting the required top end on the engines? Not sure what they are rated at but I would expect somewhere around 4400 RPM's.

I wold run everything past a good prop shop, weight of the boat, engine rated RPM etc.

Welcome to the sandbox. Enjoy the ride

Tony Meola wrote: ↑Feb 23rd, '23, 21:35 I assume Borg Warner Transmissions. If the engines shake a little you will get a rattle in the transmission when it is not engaged. We had that with a cold start up when we had the Big Blocks. Just of quirk of those transmissions.

How much weight are you carrying? Planning at 2400 with the 454's seems a little high. We used to be able to hold a plane at 1600 RPM's running 18X19 3 Blade.

I have to say that was with a light boat. Full fuel but not loaded down with equipment. Going offshore carrying ice, extra fuel, 5 guys, etc. We still go up on a plane at less than 1800 RPM's.

Are you hitting the required top end on the engines? Not sure what they are rated at but I would expect somewhere around 4400 RPM's.

I wold run everything past a good prop shop, weight of the boat, engine rated RPM etc.

trans are ZFs. The boat is super light. I've removed the galley and bathroom and head. There is no wood in the decks all coosa, no tower and pvc boards glassed together for deck stringers. Its probably as light as a 31 can be barring those with complete coosa rebuilds. I honestly think its too light. They full rpm range is 4400. I only get about 3800 on port and 4100 on starboard.

I am at 24 mph at 2700 rpm the mph fall pretty quickly with higher rpm. Max speed is 33-34mph at 3800 on each motor. What are you thinking I should look into? The bottom is clean.

If motors are running good, you’re overproped by a lot.

Why did you change from 17 x 17 to 18 x 18? That is a lot of wheel to add. Where you’re over-revving with the 17’s?

Overprop and you may go faster for awhile till your motors say no more.



Knock- what is the shaft doing when you hear the knocking? Is it bouncing around in the stuffing box or running true? If bouncing it could be hitting the box or hull

Check alignment, check shaft for straightness

Carl is right, something is wrong. First, I would check the tach's. They both should top out at the same RPM. One tach may be off slightly from the other but not that much. I would suggest using a handheld photo tach on each engine to check to see the true RPM of each engine.

Once you make sure the tach's are right, or how far off they are, you can then proceed to the props. Sounds like something is going on there. What were you turning on the top end in RPMs with the 17-inch props? If you were at 4400 RPM, then you need to go back to those props.

I really think you need to have a conversation with a good prop shop. With the boat full of fuel and all of your gear, do you have any idea how much she weighs. Usually, the travel lifts have a scale on them. I know mine with the diesels and full fuel is 12,500 lbs. You will need that for the prop shop to come up with a suggested prop size.

the 17x17's were replaced with the 18x18's because it took 3200 rpm to go 24 mph and it just felt like the boat was sitting in the water too much, almost like it was aft heavy. The motors did turn up to 4400 with the 17's but just seemed like they were straining and always working hard. Top speed was 27mph. There was very minimal mph gains between 3000 rpm and 4400 rpm. The 18's came off a 31 and the owner claimed he went through a bunch of props before settling on these particular props --- doesn't mean they are "correct"... The motors have 1300 hours on them and I would like to make them last. I've pulled both out and done the motor mounts - mainseals - oil pans - oil pumps - heads - injectors - wires - distributors - all new hoses, elbows, risers, manifolds, water pumps and iridium plugs

It seems the motors are "happier" but thats just to my inexperienced ear...if they aren't right...not really sure. My mechanic did help me pick them out and had a lot of time on the boat before and after. He was really pushing for a different set of props.

I'd bet that the tachs are reading accurate as well but I can double check. Either way the motors get about 300 less rpms.

I have been having cutlass bearing issues on the starboard motor but that motor has more rpm than port and port spins freely by hand.

As far as weight I would imagine about 500 pounds lighter than an average 31 but not sure as to actual weight

When I try to play with props I leave the feelings and gut instinct out of it and go with real numbers.

First thing I need to see, as Tony mentioned, is to verify the boat's tachs are right. If not, everything moving forward is nothing more than a guess.

Next, the boat goes for a ride and we find a place to open her up to WOT and see the rpm's attained. Boat should easily hit the rated WOT. For sake of argument, it's supposed to be 4400...if I see 3800 on one and 4100 on the other after a couple of seconds at WOT, I bring the boat back in.

Assuming the bottom and running gear are not fouled and with a belly of good fuel-

The motors get a complete tune-up, maybe a compression test if easy enough.

I'd also do a quick check to see if each shaft turns freely "By Hand". If not, I check the alignment, if I cannot align...shaft may be out.


Go for a ride and check for WOT, -

If the same results...keep an eye on the shaft for a wobble at idle and low speed, and be aware of vibrations. Could be a bent shaft, a wheel that is out or bad cutless.
Now I pull the boat and wheels, check shaft and cutless.

The wheels I bring to have checked out by a good prop shop. Obviously, if they are banged up they will not perform, but wheels can also have a blade not tracking correctly, out of balance or they may also be modified to a different size. Yeah...some shops are lazy and do not restamp the numbers when changed. So a wheel stamped 17 x 17 could be 17 x 19 or...
In short we need to verify they are good and the size/pitch.

If all good, now maybe I look into repitching or trying another set of wheels.



Back to you...Me, I'd have the 17 x 17's checked out and put them back on, get your correct WOT. At that point IF motor over rev's, we can add pitch, cup or go Up in diameter with a lower pitch, try 4 blade...it all depends on what your looking for and how much RPM you have to play with. If under reving depitch or find out why. Same wheels should give very similar performance between the two motors.

One motor turning 3800 and the other 4100...maybe 2 different wheels, or one motor not performing pulling the other down.

When motors are hitting the correct WOT rating, you can make changes to get better speed and performance but only withing the realm of the motors hitting WOT.

You said the 18 x 18 came off another 31...all well and good but did that boat have same setup, same hp motors, same weight. Its a good ballpark, but may not be an apples-to-apples comparison. Even if the same ...if your motors are older with more hours they may not be capable of producing the same HP they once did. If not the wheels get depitched so you hit WOT and boat goes slower, but motors live longer.

Carl,

I want you to read to me the same fairy tail before i go to sleep.
So mellow your paradigms!
LOL hahaha

Carl is right.

If everything is correct you should be close to 30 knots at the top end or around 34 MPH. Each boat is going to be a little different, that should be ballpark number.

Check everything else out first. Something is wrong is one engine does not hit the same RP's as the other.

If you were running at cruise, let's say 2800 RPM's. Did the engines sound like they were synced up? If you couldn't sync them up within reason on the RPM side, then something is wrong. My old tach's use to be off from each other by 100 RPM's. But I could get them sync pretty easily following that difference. Since the repower and new gauges they are both spot on.

By the way, my guages were off by 100 RPM's at cruise snce the boat was new.

For the longevity of the motors, attaining the rated WOT comes first, along with not overheating, running smooth and then speed should be looked at.


I bought my boat with 1200 hrs on rebuilt 440’s. I ran it an easy 2000 hrs over the next 25-ish season. Lots of trolling hours, especially by prior owner. Anyway, early on the motors cruised the boat 19mph at 2850, topped out around 30mph at 4400rpm.
Over the years the motors continued to run great (aside from ethanol years with a glass tank), but they did get a little tired as time went on and hours racked up.
To keep hitting 4400 WOT, I had to remove a little pitch over the years. So when I finally put my well running motors out to pasture, I was cruising 17mph at 2850 and full out WOT she’d only hit 27mph.


Yes, 17 mph is slow, BUT WHEN AND iF I wanted to get somewhere, I’d push the throttles up without a care. Aside from fuel burn…Floscans always let me know those motors could be very thirsty, but that’s another story.
Point is for longevity, make sure you hit your rated WOT. Use other people’s performance as an indicator that something in your setup may be wrong. Motors are not producing the rated power… find out why. Bent shaft, wheels out, etc. if you can over rev, now you can safely add more wheel which then brings up speed.

I think I beat this horse enough, my coffee is finished, I’m off to walk the dog who’s got his legs crossed walking funny waiting for me.

Congrats on the new boat. It is a very nice platform for diving and day trips. Albeit rocky due to the deep V while on anchor if there are wakes. But, you'l be in the water, or leaving the dives site..at least that's how I operate. If you make it out to Man O War Cay give me a shout. I have tools and resources if you need assistance.

SteveM wrote: ↑Mar 6th, '23, 12:20 It is a very nice platform for... day trips.

Steve may have more elevated expectations for accommodations than some of the rest of us. Amberjack is a 31FBC and we spent 5 weeks aboard last summer. Four weeks at a stretch in British Columbia and another 3 long weekends around Puget Sound.

Sure, it wasn't the Ritz Carlton but the scenery and enjoyable boating in BC more than compensated. That being said, we've spent the last 25 years adapting the boat to our needs. It had an enclosed head so that was good. We found a good cooler for the cockpit and modified it to hold ice longer (plus we found some great sources for clear ice). Modified the forward berth to sleep two if barely. Invested in a solar shower (cheap) and had a privacy curtain made for the engine companionway so we could shower in privacy in an anchorage. Updated the dinette for seating comfort. All the little things that make 4 weeks in close quarters bearable. It works, and to look at it it is still a very stock Bertram 31. I might even try salmon fishing this year.

Doug,

There are some fridge/freezers that are supposed to work with 12v off a car lighter type socket. The type of fridge you could use in a car, for a weekend trip.
Although they will never be the all around fridge /freezer of your dreams, I wonder if they could just be fed by a pliable solar panel you could place somewhere on the deck or fb.
What is the usable sunshine hours per day over there? Just to be able to get rid of the eternal search for ice , that is.

I agree, last year I spent 105 nights in my 28 which, like yours, is made to accommodate up to 2 pax almost forever, I mean so long as the temps are ok without the need of a heater. After that, (October-ish for us) it is time to return home!

Yannis 12v refrigerators are out there but I don't think they are efficient enough yet for our needs up here even with a solar panel. We have reasonable sun but not close to yours. I agree, we are always thinking of our ice status which is the crunch point That and the holding tank. We managed to configure the boat for up to four days at anchor without battery charging or outside support. We don't need air conditioning up here which is the big electrical draw for most Bertram boating climates and LED lighting keeps evening battery load minimal. No generator required.

Were I to start over I would build a hard Bimini with permanently mounted solar panels. And then I would install a 12v refrigerator/freezer!

For heat and cold weather cooking we have a Dickenson diesel range which cranks out enough therms that we need to leave the companionway door open. I have whiled away some pleasant days at snug anchor in bad weather making cinnamon rolls. That range is hardly used these days as we have become more fair weather boaters. Summers we use a butane cooktop.

If your fridge is well insulated AND top loading, you could perhaps do with a flexible solar panel. If you don't want to install anything permanent on top of the bimini you could just place the flex where the sun is...not as efficient as a hard mono crystalline but certainly better than ice. Do the math with the amps, it might be doable.
I have a butane two burner cooktop and with the same 5kilo container I also have a hot water heater. Its a dream!
Holding tank Im not familiar with, what is the law up there? I understand that if you are at anchor in a secluded area it shouldn't be a problem, if you're in a marina you can use the bathrooms/showers, no?

Yannis

With some of today's new cookers, you could easily make a 4-course meal using an inverter to generate power to run them. Plus, a propane Coleman camp stove works wonders. We used it offshore to heat up dinner and make coffee. A couple of small propane cylinders and you are all set. We set it up on the deck, pull out the premade pot of stew and have at it. You could fry eggs on it, or even a steak.

Simplicity at its best.

Tony,

You cannot run a cooker PLUS a fridge freezer with solar, with the available real estate of out boats.
The most you can get without ruining the aesthetics of the boat or its aerodynamics is two panels. When I installed mine I chose one of the best brands and the technology at the time permitted 2X130w for the size I chose.
Recently, I looked for what is available and I think I saw 2X170 or 2X175w for the same size. Not bad at all! With 10 hours of usable sunlight, those extra 80w produce an additional (800w/12v=roughly 70) additional amps!

As for the cooker, I started with a Coleman type burner myself, and then I realized that life is short and quickly moved to a house type two burner cooktop...I could now open a restaurant in the marina lol.

As for the oven, where last summer I cooked miracles, I use the Coleman portable oven! It can fit a small dish for two portions but why would you need more? Plus it is almost an attraction...nobody has ever seen a cooktop oven before...not even myself!

Hello TwoCoconuts-I hope you found some of the answers you were looking for when you posted on the forum. Some topics like your engine question take off like a rocket. Try asking for engine oil recommendations if you really want to generate a response.

My discussion with Yannis on marine heads and holding tanks has drifted off subject so I'll open a new topic on that.

Let us know how it goes with your new B31.