Campbell Boat Owners Website
Article by Campbell Boat Owner Ron Fasola, owner of "Strange Brew"
When you spend years messing around in boats and in the workshop, reading various boating magazines, researching specific topics, and experiencing terrific failures and a few successes on little projects, you inevitably acquire a library of useful little tips, facts, hints, and methods that make life easier. Listed below are a bunch of these "factoids”, which cover a conglomeration of topics that range from very basic "beginner" status to things no normal person should care about. Some of the material below was shamefully plagiarized, but it's all true!
Wood saws, hack saws, and metal files are all designed to cut in ONE direction only; usually in the "push" stroke. Most folks understand this when using a wood saw, but seem to forget that this also applies to hack saws and files. Lift the blade or file on the backstroke so it ever so lightly maintains contact with the work piece, to avoid dulling the cutting teeth. There are specialty, (usually fine cut), wood hand saws that cut on the pull stroke, and some files that do not have a directional bias, but they are the exceptions.
Even when filing metal correctly, metal particles from the work piece will stick in the file teeth, sometimes even on the first stroke. Particles stuck in a file will create deep scratches in the work piece on each successive stroke, (galling), so it is essential to have a "file card" nearby. A file card is basically a flat wire brush made expressly for cleaning files. Aluminum is a great offender for clogging files, because it is so soft. You can check the file visually every few strokes, or watch for scratches in the work piece to tell you when your file has a stuck particle in it. If you file a lot, you will eventually feel the stuck particles through your hands when you file.
If filing aluminum, use a special aluminum file. Aluminum files have larger, arced teeth and leave an almost polished surface. They also clog very easily.
It matters in which direction a piece of metal is filed when held in a vise. It's almost impossible to file "against" the piece. When the file sticks, or the whole vise/bench seems to be vibrating, stand on another side of the work, re-set the work in the vise, or somehow change your set up. This probably won't make sense until you encounter the situation.
Use "draw filing" when seeking a finished appearance on a work piece. Draw filing is a filing technique where a single cut file is held 90 degrees to the stroke. A clean file is essential to prevent galling, so frequent use of a file card is required.
When using a drill press, there are readily available charts to show what arbor speed to use as a function of drill bit size and material. That's pretty basic, as is the use of cutting fluid, (not lube oil), with thick metal, and using a center punch to mark the location of the hole and to prevent the drill bit from wondering off the intended location.
When drilling metal with a sharp drill bit, and the removed metal comes out as a continuous spiral that spins around the drill bit that seems to be hunting for your hand to cut, here's a tip: Ease up on the drill press boring handle momentarily, and the formation of the spiral chip will be stopped, and the spiral will usually be flung off the bit. So the process of drilling through a relatively thick piece of metal becomes a series of easy "pumping" motions on the drill press handle, with each "easing up" motion ending a spiral chip. Stop the drilling process and remove long spirals if they don't fling off and are annoying. Cast iron doesn't produce spirals, and aluminum is the "spiral king". Fanatics that can't stand metal chips everywhere sometimes place a magnet near the drilling area which will catches most of the chips. Personally, I don't want to run the risk of magnetizing anything I own, except for screw retrievers.
Although we all know that the work piece should always be clamped in some fashion when using a drill press, we nevertheless all hand-hold work pieces at one time or another. When hand holding, be especially careful, and hold on to the work piece extra firmly, when the drill bit is just about to go completely through the piece. That's the time when the work piece is most apt to spin and cause injury because that's when the drill bit meets maximum resistance.
There are a lot of misconceptions about stainless steel. Because it is so difficult to drill, cut, and polish, it's usually assumed that stainless is extremely strong. Surprisingly, stainless steel fasteners are only about as strong as SAE Grade 2. There are some alloys of aluminum that are stronger. So don't ever replace a graded fastener with a stainless bolt. A Grade 5 bolt has three lines on its hex head, and a Grade 8 has 6 radial lines on its head. In metallurgical terms, stainless is "tough", but not always strong. There are over 100 differing alloys of stainless steel, but most commercial fasteners are either 304 (18-8), or 316. Most of the stainless used in marine applications for bow rails, chocks, etc. is 304. 316 is used more in the medical and food industries, because of its slightly better corrosion resistance than 304. Most stainless sheet metal or machine screws are made of type 410 stainless. A quick check to identify stainless fasteners is to use a magnet; stainless is not magnetic.
Although corrosion resistance is a big part of the reason stainless is used frequently in marine applications, stainless can indeed corrode. Stainless fasteners, especially low-quality stainless steel fasteners, when used below the water-line, can deteriorate from lack of oxygen. Also be advised that stainless steel can rust.
Drilling holes in stainless steel should be done with Cobalt drill bits. The slightly lower quality titanium bits won't last too long when used on stainless. Using about three successively larger drill bits, (essentially three pilot holes), makes it easier on any drill bits in any metal.
Polishing stainless steel demands high speed and high pressure regarding the polishing wheel. The work piece will and should get hot pretty quickly; that indicates polishing work is getting done. Use gloves. Dipping the work piece in water to cool it off during polishing works fine, if that is practical for the job.
This is a huge topic, but basically:
Before using a rag wheel on a motor with the appropriate polishing compound, use wet sanding paper in finer and finer grades with water. The water flushes the removed metal from the sand paper, and the wet sand paper lasts much longer than any dry or emery cloth type of paper. With small work pieces, work over a bucket of water, constantly dipping the work piece and sanding block in the bucket. This works well with aluminum and stainless steel.
Drilling in Wood
Although metal drill bits are routinely used for drilling holes in wood, even a cheap set of brad point drill bits will do a better job of providing a smooth hole. Brad point bits have a sharp starter point, and are JUST for wood.
It may sound snobbish, but spade drill bits should be outlawed. Get a set of Forstner boring bits and your life will be much happier. Most drills are guided through the material by a central point, but Forstner bits are guided by their outside rim. This means they can be used to drill holes at an angle, partially overlapping holes, and holes that are on the edge of the work piece. They can also create square-bottomed holes, called "counter-bores", which allows hex head bolts to be flush with the surface. They can also be used to hog out material, (like making floorboards fit over battery terminals!).
Regardless of the type of drill bit, when drilling through thick wood, pull the bit out every ½ inch or so, to insure that the bit is clear of the removed wood. When the bit feels like it needs more pressure to continue drilling, chances are it is clogged with already-cut wood. Smoke from the wood burning is another more extreme signal that not much drilling is taking place.
Cutting Rubber Hose
This is rather gross, but it works. When using a razor knife to cut rubber hose of any diameter, first spit on the back of your hand and run both sides of the razor blade through the saliva. You'll be amazed how easy the "lubed" blade then cuts, especially when you bend the hose so that the cut line is "open". Lube frequently through the cut. Don't let your wife see you do this.
Basic Wood Screwing
Soft woods require coarse screw threads, hard woods require finer threads. Nowadays, drywall screws are used for woodscrews almost exclusively, but there ARE better choices for critical applications. However, drywall screws do work for many wood joining applications and are available in stainless steel. Even though today's cordless drivers have enough power to sink drywall screws into hard wood, drywall screws are not really that strong and it's preferable to countersink the holes in hard woods just a little before inserting a wood screw. The angles or profiles of typical counter sinking bits and drywall screw heads are not identical, but they're close enough.
When using wood screws to attach one piece to another, say, a floorboard to a stringer, many people simply drive a screw through both pieces. There's a better way. Since the intent is to hold the first piece tightly to the second piece, a hole sized to allow the screw to easily pass through the first piece, (the floorboard in this example), should be drilled. This way, the screw does not just tighten up in the first piece and thereby not provide much holding force between the two pieces. When a screw is placed through the hole and tightened, the screw will turn freely in the first piece, and dig only into the second piece, (the stringer). As the screw is tightened, it will then pull down the first piece, (the floorboard), against the second piece very tightly. A pilot hole, (a smaller diameter hole than the screw itself), may have to be drilled into the second piece. This technique applies to any two pieces of wood being screwed together – drill a hole the size of the screw through the first piece.
Normally, to size a pilot hole, use the "root" diameter of the screw, which is the diameter of the screw minus the threads. When drilling pilot holes in fiber-glassed stringers, a larger pilot hole is required because fiberglass is pretty hard. When drilling into gel coat, and even larger pilot hole is required to avoid chipping of the brittle surface. Before final drilling into gel coat, use a counter sinking tool with a light touch to help prevent chipping.
These suggestions are just basic geometry and well known, but may be unknown to some.
To locate the center of any square or rectangle, forget measuring. Simply draw diagonal lines connecting the opposite corners. Where the lines intersect is the center.
When desiring to divide a given length, (a 3 foot, 7 inch square piece of plywood, for example), into a given number of even spaces, (say, four in this same piece of plywood), again forget calculating. Lay a long measuring straight edge between the edges of the plywood so that the zero mark and the 4 ft. mark, (in this example), are on the opposite edges. Then mark where the 1ft, 2 ft, and 3 ft measurements are on the board. The idea is to make any length divisible into easily known divisions by picking an easily divisible straight edge length.
When marking a work piece with repetitive measurements, use a divider. Trying to measure and mark each time will generate errors that will accumulate and end up being appreciable. Dividers provide a consistent measurement and help avoiding compounding measuring errors. When using dividers to transfer center to center dimensions of holes, don't try to guess the center of the two holes when setting the dividers. Instead, use either edge of the two holes, like both right hand sides. That's the same dimension of the center to center distance, and is a discrete dimension you can set the divider to match.
When marking metal, thick pencil or felt pen lines make for error. Use layout blue fluid and a scratch awl instead. The fluid comes in a can with various kinds of application methods, most are like applying PVC glue. The blue fluid is easily removable from the work piece later.
When dealing with large areas, say 10 ft or more in any given direction, on things like carpet or flooring, and you want to lay out a square, here's a tip. The diagonal measurements of a square will be equal. This means that if you're trying to lay out lines for a 20 ft. by 20 ft. area, keep moving the four corners around until both diagonal measurements are equal, (in this case they will be equal at 28.28 ft.)
Theoretical Boat Speed Calculation
Prop pitch is the distance the prop would travel forward in one revolution, with zero slip. A 14 x 15 prop has a diameter of 14 inches, (the first number), and a pitch of 15 inches, (the second number). So in one revolution, a 14x15 prop would travel 15 inches forward.
Therefore, for a typical 24 ft. Campbell, which has a prop slip factor of 15%, the calculator below can be used to approximate the mph speed. However, be advised that although any combination of rpm and prop pitch can be used in this calculator to produce a theoretical mph speed, the real world is a lot different. Stock motors cannot pull say, 7000 rpm with a 15 inch pitch prop. So the way to use this calculator is to observe what the Wide Open Throttle, (WOT), rpm of your boat is, and use that rpm in the calculator. Freddie says that most stock Campbell's went out of the factory with 1.04 under driven gear sets in their V Drives. Custom built motors are usually dyno'd and designed to run at a particular rpm that the engine builder decided upon. In those cases, that design rpm would be the rpm to use in the calculator to determine the effects of different prop pitches and gear ratios. There are also a whole slew of other factors that effect the choice of prop to use, like the clearance between the prop ear tips and the bottom of the hull, the prop's cup, how a particular prop "carries" the boat's nose, etc. The bottom line is please don't put too much importance on this calculator; it has severe limitations. Before you invest time and money on changes, talk to the pro's.!
Therefore, for any boat:
Miles/Hr = (engine rev/min) x (prop rev/engine rev) x (prop pitch in inches/1 prop rev) x (1 ft./12 inches) x (1 mile/5,280 ft.) x (60 min/hour) x (prop slip factor).
For example, here's how the numbers work out for my particular 24 ft. Campbell, which has a 14 x 14 cupped prop, 1.15 under driven gears, and can rev to 6,000 rpm:
Mph = 6,000 x 14 x 60 x 0.85 = 58.8 That's about right for my boat; 59 mph at 6,000 rpm.
1.15 x 12 x 5,280
So if that boggles you rmind, here is a link to an MPH Calculator in the
form of an Excel spread sheet.
So if that boggles you rmind, here is a link to an MPH Calculator in the form of an Excel spread sheet. Click Here!
Safe Prop RPM
Jim Wilkes, of Hot Boat Magazine, recommends never spinning a 3-blade bronze prop over 4,500 rpm, (remember that the V-drive ratio must be taken into account to determine the prop rpm).
Stainless props can spin higher, but for huge horsepower and/or maximum strength, steel props must be used. Phil Bergeron uses stainless props for motors up to 800 HP. Over that, he uses steel props, which are stronger.
All the magazines recommend that all fuel lines, fuel fill lines, and fuel vent lines be changed every 10 years, at a minimum. With today's ethanol-laced gasolines, older hoses, (pre year 2000?), should be replaced as soon as possible, with new rubber hoses that are designed to withstand the effects of ethanol. These new hoses meet and are marked with a spec called J1527, which means it is Coast Guard approved for Type A-1 service; unleaded gasoline and blends of ethanol, (E10). Fuel hoses now also have the date of their manufacturer imprinted right on the hose, which reveals immediately when it's time to replace them.
For the larger fuel fill hoses, it is required that the hoses incorporate a helix metal wire in addition to meeting spec J1527. This helix wire type hose is also used for any line that may be subjected to a vacuum, and is used for the connection of the water inlet through-hull to the water pump inlet. If a sea strainer is in the water inlet system between the through-hull and the water pump, helix wire hose is used for both its inlet and outlet connections.
Stainless braided hoses for water and fuel used to be the pinnacle mark of meticulous boat rigging, but not all stainless braided hoses are created equal. Over time, gasoline breaks down the plastic inner lining of older braided line, and catastrophic leaks can suddenly occur. There is really no way to see that the inner lining is disintegrating, which is one of the reasons why braided stainless fuel lines, even the improved lines of today, are not Coast Guard approved.
Casale C-500 Gear Ratios
C-500's gears are available in five ratios of 1.04, 1.10, 1.15, 1.22, and 1.29 to one. The position of the gears in the V drive can be swapped to provide these same ratios in either under driven or over driven configuration, which means there are a total of 10 gear ratios available.
Champion V-Drive Gear Ratios
Phil Bergeron said Champion V-drives were available, (they are no longer made, but gears and other parts are still around), in ratios of 1.04, 1.09, 1.15, and 1.285. Phil also told me that despite folk lore, it is not practical to simply turn a Champion drive upside down to go from under driven to over driven; Champion V drives should be taken apart to swap gear positions, just like one would do with a Casale C500.
The original manufacturer of the windows on Campbell boats was Meksol. They went out of business years ago.
When rebuilding a stock big block Chevrolet starter, it is possible to use a more heavy duty solenoid that usually is used on diesel engines. The diesel solenoid fits on a stock BBC starter. It is also possible to have the starter rebuilt or modified to be "higher torque".
If your BBC engine seems to be harder to start or turn over when it is hot, (this is very common), then wire in a Ford starter solenoid into your starting circuit. This simple and inexpensive modification is common and easy to do. It basically ensures that the voltage delivered to the starter is higher, which solves the low voltage issue that is the underlying cause of hot start problems.
The bronze log, (the through-hull for the prop shaft), commonly found in Campbell V-drive boats is simply fine threaded into the hull glass and sealed with silicon. If necessary because of water leaks in this area, it is possible to remove its bolts, clean it up, and replace the silicon under it without removing the shaft.
The rubber hose diameter on the stock Campbell adjustable plastic prop shaft through-hull seal is 1 ¼" ID. It's a good idea to install a locking collar around the prop shaft just inboard of the bronze log through-hull to help retain the shaft in the boat if an object is hit by the boat at speed. The same thinking applies to rudder shafts.
When using silicon as a bedding or sealing material, here's a handy trick: Apply a bed of silicon under the piece to be screwed or bolted into something, and then LOOSELY snug up the piece with its screws or bolts. Allow the silicon to set up for a few hours or overnight, and THEN tighten the screws or bolts to their eventual torque. If the piece is tightened immediately after the silicon was applied, most or all of the silicon gets squished out of the space between the parts. Allowing the silicon to set up a little before final tightening will provide the "gasket property" desired for attaching/sealing the two parts.
Many Campbell boats have GM Turbo 400 transmissions in them. First gear is fairly low for marine use, and is sometimes "locked out" so that the transmission is essentially a 2 speed tranny. The "park" position is also sometimes omitted, but some feel it is handy to lock the prop shaft for easier prop removal.
Since the transmission faces "backwards" in a V drive boat, the oil pick-up in the transmission is reversed to the other end relative to an automotive application. So V-drive Turbo 400's require a different filter screen than a normal automotive screen.
MagnaFlow Water Pump Impellers
Boats stored in Lake Havasu can sometimes need their MagnaFlow water impellers changed in under a year's time, (cracks at the base of the vanes begin to appear). People in other parts of the country report impeller life up to five years. Most industry professionals familiar with Havasu recommend changing impellers at the start of every season. Discussion with the fellow who designed the MagnaFlow revealed that storage heat is the major factor that causes impeller vane cracking, deformation, and/or disintegration. In Havasu, boats stored in enclosed metal rental storage spaces are subjected to ridiculously high "soak" temperatures over the summer, and boats stored in open but covered areas, (like under an awning), fare only a little better.
It helps to turn the motor over routinely even if the boat isn't run, just to reposition the impeller in its housing. Don't allow the engine to start or run when "chucking" the motor, because it takes only a few seconds to ruin an impeller when there is no cooling water present. A piece of tape on the crankshaft pulley can be used to ensure that the engine is turned over 180 degrees. Remember that the cam, (which drives the impeller), turns at ½ the rpm of the crankshaft.
The best solution, when the boat is not going to be run for a few weeks, is to remove the impeller and store it inside a cooler home or a refrigerator! The vanes don't take a set this way, and the storage temperature is greatly reduced. Depending on your mechanical skills and the accessibility of the pump, this may not be a difficult thing to do. As a reminder, when the water pump impeller is out, attaching note to the steering wheel not to start the engine is helpful.
Don't use WD 40 or any type of petroleum lube when stuffing the impeller into its housing; use a liquid dishwashing soap like Dawn because it has slippery glycerin in it that doesn't harm the neoprene impeller. As you push the impeller in, twist it in the direction it will be turning when the engine is running. Pro's chuck the engine while pushing in on the impeller and make a half hour project into a one second move.
The designer of the MagnaFlow pump also said that the wearing away of the chrome on the inside of the pump is not a problem. It was only chromed because it is too expensive to mask that area off in the chroming process.
Obviously, revving the motor high when trying to dislodge the boat from a beach is to be avoided because sand will be sucked into the water pump and can dramatically wear the impeller and pump housing.
It's common knowledge that if an impeller DOES come apart during operation, all the rubber vane pieces must be retrieved and accounted for. The vane pieces usually get stuck at 90 degree water hose connections. If over-heating is noticed after an impeller mishap, it usually means there is still vane parts stuck somewhere in the cooling system.
Although it is commonly done, it is not a good idea to use automotive tires on a boat trailer. Nor is it recommended to use LT (Light Truck) tires. But for "trailer queen" boats that only get towed to the ramp from a local storage, many people use automotive or LT tires. However, for serious towing, only ST (Special Trailer) tires should be used. ST tires have stiffer sidewalls to help control trailer sway.
24 ft. Campbell boats weigh 5800 lbs. dry, with an I/O drive. Add a trailer, equipment, fuel, etc. and the numbers add up quickly. 8 ply tires in 225/75 R15 size at 65 psi each will carry 2540 lbs., (10,160 lbs for 4 tires).
Unfortunately, the rest of most stock 24 ft. Campbell trailers, (axels, primarily), are not designed to carry 10,000 lbs., but it's good to be on the safe side regarding tires.
Gary at Enduro Trailer in Havasu said that because boats stored in Havasu never get their bearings hot enough to burn off any water that gets in, corrosion is common. He explains why Buddy Bearing protectors are better than nothing, but not very effective. A grease gun generates tremendous pressure, but the seals can only hold about 3 psi. Besides, the grease coming into a Buddy Bearing hits a washer that basically covers the outside bearing. He thinks a routine bearing inspection and re-greasing is the best policy.
It appears that trailer bearings should be checked and re-packed with grease about every 3-4 years on boats kept at Havasu that don't see much highway use.
From an article about rewiring boat trailers, the convention for wiring colors is:
White = Ground
Brown = Taillights, license, side markers
Yellow = Left turn, stop
Green = Right turn, stop
Blue = Electric brakes, aux, or reverse gear brake lock out on disc brake models
Never use spade electrical connections or terminals, always use ring connections.
If available, use ring terminals with heat shrinkable covers. Or, use "Liquid Tape" on the connection, which goes on like a thick liquid and semi-dries. Liquid Tape is great for trailer wiring that will go underwater routinely.
For marine wiring, multi-strand wiring is mostly used as opposed to solid core wire.
Attaching two wires together is best done by stripping the covers off the ends, slipping an appropriately sized piece of heat shrink tube over one wire, twisting the wires together in a parallel fashion, adding flux, and soldering them together. When the wires are cool, and the flux is wiped away, pull the heat shrink tube over the soldered connection and shrink the tube with a lighter, (carefully, because it's easy to scorch the tubing), or a heat gun. For extra measure, use Liquid Tape over the whole mess. Butt connectors can also be used, and do work just fine.
When buying a soldering "gun", buy the highest wattage model available. Low power soldering "irons" are just plain frustrating to use.
To connect devices that may be removed later, like bilge pumps, it's a good idea to use quick disconnect or snap plugs, but tape or protect the joint as much as possible.
VHF radios, stereo's, depth sounders, and other marine devices operate best with very direct grounds. The same can apply to 12v positive sources. It's not practical or good rigging to run each such device's ground or hot wire directly back to a battery post. Instead, use a small, (about 5" long), minibus for consolidating either multiple ground or positive wires. Run a hefty wire, (12 ga.), from the minibus to the appropriate battery terminal, and connect all the devices to the minibus. The minibus can be mounted wherever it is convenient.
If you don't have the correct colored wire for the job, say red for a hot wire, and you want to use a black or white wire for a hot wire, it's an accepted electrician's practice to use red tape at both ends of the "off-colored" wire to denote it is being used as a red hot wire. The same method applies for other colored wires used as black ground wires; use black identifying tape. This practice will help anyone working on your boat, (including you, later), to decipher the wiring.
This is very basic, but to determine if a light bulb is "burned out", rather than rely on being able to see the broken filament, use a multi-meter to check continuity between the center contact and the bulb's rim, or between the two contacts on the bulb. As your eyesight degrades with time, this practice begins to make more sense.
Most electrical work on boats is obviously DC, but when dealing with AC, there are some handy conventions to know. Looking at a typical lamp cord, or "zip-cord", (two insulated conducting wires held together by an easily separated jacket), there is one wire that has ribs, and one wire that is smooth.
By convention, the smooth sided wire is the "hot" wire, is connected to the small spade end of the lamp plug, and usually connects to the black wire of whatever device is being powered. In a lamp, the hot wire connects to the center connection of a light bulb socket. This also applies for DC flashlights and DC bulbs.
Conversely, the ribbed wire is the "neutral" wire, is connected to the large spade end of the plug, and usually connects to the white wire of what is being powered. In a lamp, the neutral wire connects to the outside of the bulb socket. This also applies for DC flashlights and DC bulbs.
A green or bare copper wire, if present, is the ground wire.
In general, when wiring a 120v AC wall socket, (receptacle), the black or hot wire(s) are wired to the darker screws, (the brass colored screws). The white or neutral wire(s) are connected to the light, or silver colored screws.
Timing Specs for BBC's
A good, safe, timing curve for a BBC is to set the basic timing (idle speed) at about 10-12 crank degrees, and total timing at about 32 crank degrees. The 32 degrees should be "all in" by about 2500 rpm. This is a conservative setting, because the octane numbers of today's fuels are not like those in the past, and it's usually hot on the lake. Many other variables are actually involved, like compression ratio, octane of the gasoline, etc., but this above curve shouldn't get you into detonation or "knock" trouble.
A call to Holley's tech line revealed that power valves begin to open at twice their rated full open value. So a common 6.5" Hg power valve actually begins to open at 13" Hg. This means that one should check the vacuum of a particular engine at idle, then select a power valve that is less than at least ½ that value in order to prevent the power valve from partially opening and providing unwanted fuel at idle.
On a Holley carb, if you ever find that it is possible to turn in both idle adjustment screws until they bottom out, and the engine is still running; there is a problem. It means the carb's throttle plates are too far open at idle, and slots in the throat are being exposed, (which shouldn't be), that are pulling fuel into the venturi. When this happens, the idle mixture jets are useless because much more fuel is being pulled into the throat through the slots, making the jets' contribution negligible. All this can be caused by the timing dwell being so far off that the idle speed screw on the carb has been set so that the throttle plates had to be (incorrectly) opened this far to just to keep the motor alive. But when the idle screw is opened this much, the carb is way off. Check the dwell.
Power valves don't last forever. They have rubber parts, which deteriorate and/or get stiff or swell over time. They last years, but don't completely forget about them.
The typical "thing" atop a marine carb is a "flame arrestor", not an air filter. As its name implies, its job is to quench any flame that may start at the carb by absorbing the heat instantaneously because it is made of metal. It does nothing in terms of filtering the inlet air. A fiber gasket ring under the flame arrestor used to be quite commonly used. Because these gaskets can become gas-soaked and therefore become a fire hazard, the Coast Guard has disapproved their use.
Big, giant, carbs like an 850 cfm double pumper, won't really help a stone stock low performance engine. In fact, it will probably hurt performance and massacre fuel consumption. The basic idea is to maintain high velocity through the intake system, and if the heads and cam are not suited for huge flow, a big carb actually reduces the velocity. A Holley tech told me that even with my modified heads, replacing my 750 cfm carb with an 850 cfm would be only slightly worthwhile if I ran at wide open throttle quite often.
Valve Cover Breathers
With all the air going into an engine at speed, there is always some air that is pumped into the crankcase. It has to have a way to get out of the crankcase. Automotive engines have PCV valves, (Positive Crankcase Valve), in their valve covers that feed this air back into the engine intake system during certain conditions. However, sometimes marine engines are assembled with great looking valve covers that don't have provisions for either PCV valves or even breathers, (attachments to the valve covers that are open to the atmosphere). If you see your oil dipstick shooting out of your motor, or oil blowing out of the dipstick tube, it's a sure sign of excessively high crankcase pressure. The fix is to ensure that there are open breathers or a working PCV valve on the valve covers.
This is a relatively complicated topic and many variables need to be considered like type of boat, (fiberglass, wood, aluminum, etc.), the type of water it's used in, (fresh, salt, or brackish), and more. There are three metals used for cathodic protection; zinc, magnesium, and aluminum.
Basically, zinc works best in salt water, magnesium is best for fresh water, and aluminum is best for dual purpose use in both fresh and salt water, and also brackish water.
All metals generate a negative voltage when immersed in water. The lower the voltage, the more active the metal is considered to be. Magnesium generates a negative 1.6 volts, aluminum generates a negative 1.1 volts, and zinc generates a negative 1.05 volts.
For Campbell boats, (fiberglass hulls with mostly bronze and stainless hardware), in the hard but fresh water of Havasu, either magnesium or aluminum anodes can be used.
Lightning Bolt Distance
Ever wonder how far away that lightning bolt you just saw really is? Count the seconds elapsed between the time you saw the lightning bolt and the time you hear its thunder. Divide the number of seconds by 5, and the resultant number is the distance, in miles, that the lightning bolt struck.
There is no such thing as "silent lightning". If you see lightning off in the distance, but never hear it, it is simply too far away to be heard from where you are.
Fast Forwarding Charcoal
If you don't want to wait thirty minutes for charcoal to be ready for grilling, aim a hair dryer or a leaf blower, (from a distance), at the pile of charcoal right after the initial start up flame has subsided. You will think you've entered a time-warp. The downsides are that your wife's hair dryer will forever-after smell like charcoal, dangerous glowing embers are apt to be flung about, and a 110v source must be somewhat nearby for the hair dryer. This is a Tim Allen procedure, but it works great.
Prop Shaft Strut Bearings
For Campbell boats, always use marine rubber "BJ" bearings in the strut; never the hard "racing" bearings. They're called "bearings", but they look like a 4" bushing inside the strut. The BJ rubber units can pass a little sand, won't wear the shaft, and reduce vibrations.
For most lake usage, the huge Danforth type, fluke anchors that seemed to come with most Campbell boats are not too practical for Lake Havasu. The problem is that in order to "set" a Danforth, one needs to use a "scope" of about 6 or 7. Scope is the ratio of anchor rode to water depth, so in 10 feet of water, 60 or 70 feet of anchor line should be let out so that the angle of pull on the anchor is "level" enough with the lake floor to allow the anchor to bite in or set. It's usually recommended that a length of chain be used to attach the anchor to the anchor line, to aid in keeping the anchor line more parallel with the sea floor, but using chains is not that critical in lakes. To break a Danforth anchor loose, the anchor rode is pulled in until the boat is just about directly over the anchor, and then a near-vertical upward pull will usually free the anchor.
Normal anchoring on Havasu, especially in crowded areas or coves, precludes long anchor rodes and is primarily why it is so difficult to set a Danforth type anchor. The relatively new "Box Anchors" are collapsible and store easily, not too large, and work great with a very short scope of about 2 to one. They can be set almost directly under the boat. They come in various sizes, and the "small" size works well without any chain for a 24 ft. Campbell for lake use.