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424’s were made with optional opening ports. Mine had fixed ports in the head and opening ports in the aft cabin and galley. I don’t know who made them and I don’t think there is any logo on them. They are a bit hard to match if you’re looking to replace them with opening ports. At least one owner has replaced his and may have his old port if you need a replacement.
Rich
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There should be no shaft movement, lateral or vertical. If you can move the shaft in the cutless bearing it needs to be replaced. The V-drive should have no play. If you get alignment right, you should be able to run the engine up to at least 1000 shaft RPM, which is probably 2000 RMP on your tach without significant vibration. This requires a shaft that is true and has no play, a properly shaped and balanced propeller, and a good coupling. If dishes or cabinetry rattles you need to fix something. At cruising speed, I can feel a bit of vibration in my feet if I stand near the engine but nothing rattles.
If you can get things aligned in one position but they are way out of whack when you rotate the shaft, something is warped or bent. A bent shaft is common. You catch a line on your prop and this bends your shaft just a bit. A line-cutter is good insurance against this. Youâll never get it aligned with a bent shaft. If you think your shaft is bent, bring it to a prop-shop and have the check it.
Another potential problem is a warped coupling. This can happen if someone tries to remove the shaft.
Alignment must be done in the water after the boat sits for a few days after launching. Align it for a best fit in four positions, 12:00, 3:00, 6:00 and 9:00, rotating the shaft 90 degrees four times. Back off the coupling bolts just a hair, maybe .020 in. Slip the feeler gauges in there to measure the gap. It should be close to the same space all the way around. When aligned properly, you should have very little gap variation. I think I had about .003in when I last did it. I tried perhaps six times before I got it right. Iâd align the shaft as best I could and then take the boat out. If it vibrated I rechecked the alignment to see if I could do better
Rich
I canât think of any flat sections aft other than the transom, which is actually pretty thin. Iâve observed no hull flexing other than the bow which I rebuilt years ago.
If you have a sloop or cutter, the transom chain-plate is poorly attached.
Rich
Rob
You want to keep the tip speed on your propeller below where it will start to cavitate. If you repower with a faster turning engine, you may need to change to a smaller prop to keep the tip speed down. This requires changing to more pitch to counter the loss of blade size. There are efficiency issues with too much pitch however.
You probably need to change gear reduction to keep tip speed down. With about a 19â prop, you should adjust gearing to keep the shaft turning no more than about 1200 RPM. Since your engine turns 3200 RPM. A 2.5:1 gear reduction would give you this. You should contact a prop manufacturer and discuss your options before spending a bunch of money on this. Give them the specs on your engine and boat. Figure about 25000 lbs for boat weight.
My yanmar develops 75HP at 3800 RPM. Yours develops 80HP at 3200 RPM. My prop is 18.5×12. I think itâs just a bit under sized but close to correct. I would guess that a 19×13 would work very well for you. My original prop is 20×13. Yours is probably the same and could probably be cut this down to 19â. If you try to stick with a 2:1 gear reduction you may end up cavitating at high throttle settings. Youâll experience vibration at high speed and raising the throttle will increase engine speed but not make the boat go faster.
I donât think you can get an RV-20 anymore. Maybe you can find a used one in good condition. Switching to the RV-26 is expensive and a bit of work. It wonât drop-in without work.
My notes are below if you havenât already read them. Thereâs a model linked for selecting prop size.
http://www.richardcarter.net/repower/Propeller.html
Rich
That’s a nice looking engine! It comes with a 125A alternator and turns slower than my 4JHTE.
I suggest you go with the second alternator and high-rise exhaust options when ordering. The Yanmar will sit lower than your W60 bringing the exhaust outlet lower in the boat. The high-rise elbow raises the exhaust a bit. You’ll have to push the engine a bit further back in the engine room compartment to clear the front cover.
The second alternator lets you completely separate your starter battery from the house battery and gives you a backup in case your main alternator fails.
Rich
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Mine proved unreliable and was removed many years ago.RichSent from Outlook MobileKen
I don’t think you have a standard mast. It is quite possible that a PO retrofitted the in-mast furler.The ketch came in two heights, normal and tall. You appear to have the taller rig. You can view the sail dimensions for the various options at the link below.
http://baconsails.com/bacon/select_sailboat.php
Rich
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Itâs taken me years to get my boat to point and ten boat units to my sailmaker to get her competitive on the race course.
Just to put things in perspective, the sloop and tall ketch have the exact same mainmast rig dimensions. The main and foresail dimensions are identical. My sloop has the reinforced step in the cockpit and tabbing glassed to the hull for mizzen chain plates. For whatever reason, the first owner elected to skip the mizzen option. The cutter has the exact same mast but has it positioned a couple of feet farther aft. The cutter therefore has a bit larger sailing plan but a slightly lower aspect ratio. With good sails and if there were some way to tension the backstay with the ketch, I think she should point about as well as I do. The same goes for the cutter. If I had it to do over again, I think Iâd opt for the cutter. If you have a sloop or cutter, reinforce the transom chainplate. Pearsonâs solution is inadequate and IMHO dangerous.
Rich
Regarding the fuel consumption question, I can’t really tell what my fuel consumption is. I don’t keep the engine at a constant setting for a full tank full of fuel and I do a bit of idling at anchor to run the refrigeration. I therefore have no way to measure consumption. As long as I can find a place to fill-up, it’s not an issue. I would guess that we burn about a gallon/hr at moderate speed. Pulling the throttle up to press the boat past her comfort zone will start sucking down the fuel. My guess is that 6.7 kts would be where consumption starts going up. This is where she is most comfortable. My previous engine, a W60, was comfortable up to about 6kts so your mileage may vary. I usually cruise a little bit faster but I don’t normally push it past 7 kts. Fuel consumption goes up dramatically and so does the noise. She will do 7.8 kts under power at full throttle. The engine specs say that she burns 4.5 gal/hr at full load at this speed however. I run the engine at full throttle for about 20 minutes about once each month to burn off carbon deposits as directed by the owner’s manual. Otherwise I see no benefit to burning that much fuel to go less than a knot faster. If I had to conserve fuel, I’d probably run at about 5kts where I bet she burns about 1/2 gal/hr.
My previous boat liked to surf. Downwind, we could keep the 30-footer on the face of a wave for what seemed like minutes. The 424 doesn’t surf however. Still, under the right conditions she will do 8.3 kts. That’s rare however.
I think I’ve done about all that can be done with the 424 to improve sailing performance, short of gutting the interior and emptying her out. We have short races on Thursday evenings, about an hour or so in duration. The difference between the first few finishers on corrected time is typically a couple of minutes in total. Footing off a bit more would let the boat pick up speed but VMG would be less. When I tack over, the boat I passed is now to windward of me. Of course, if I pinch-up a bit I can sail a shorter course but unless there is a breeze, the 424 won’t effectively point higher.
A few seconds here or there at the start or anywhere on the course is the difference between 1st and 3rd. This gives you a chance to really compare a minor trim adjustment or coarse heading with the other boats. Our courses are always directly upwind/downwind, sometimes twice-around. This doesn’t favor the 424. Upwind is a challenge. I can point as high as most boats but I need to protect my lee. Some boats like the J24 can point higher. If someone who can point higher gets in my lee he can push me up and force me to tack over or stall. Most boats tack over and zip off on the opposite tack. The lumbering 424 takes a couple of minutes to build up a head of steam and crabs to lee until she gets going. I try to run the rhumb-line tacking only twice on the upwind leg.
I always start on starboard tack, sailing until I think I can tack-over to make about 5 or 6 boat lengths from the mark when I tack again. I always round marks on starboard too. Otherwise I have to yield and as I said, the 424 doesn’t tack quickly. If I screw up or get forced over anywhere on the course, I have to take two additional tacks to regain position, each of which cost about a minute or more on my final time. Two extra tacks and I get 3rd or 4th place instead of 1st. Another two and I’m trying to stay out of last place.
Downwind is a bit easier with the 424. Here there is no penalty for gybing as there is with tacking and therefore no lee to protect. Once we round the windward mark we can make up time we may have lost to boats that can outpoint us. I fly a cruising spinnaker and have a good deck crew to handle the sail. I find that we do very well running directly downwind with it. Everyone else zig-zags down the course trying to keep their boat speed up. Directly downwind is best for us. This heading requires careful attention by the trimmer or the sail will collapse. We could sail a bit faster by heading up in either direction but we end up sailing a longer course. We can fly the spinnaker wind-and-wing with the wind more than about 160 degrees apparent. We can broad reach from about 80 to about 120 degrees, so there is a heading of between 120 and 160 degrees where the sail doesn’t work. This sounds like a lot, but the apparent angle rapidly moves forward when you reach up in either direction.
Rich
I can make a 90 degree tack over the bottom, meaning that if I see a mark directly abeam of my boat under normal conditions I can make it. Normal conditions to me are light wind, about 5..8kts true. If the wind picks up a bit, enough to get the boat to heel, say 15kts true, I can do better, perhaps 85 degrees. The tack angle I see on my apparent wind indicator is about 35 degrees. She crabs about 10 degrees in light air and about 7 degrees in moderate air. I don’t know exactly what she will do in heavy air. I’ve always been a bit too busy to measure it.
I lose about a boat length with each tack, so if the mark is close I must pass the lay-line by about 42 feet. The boat loses headway when tacking and takes a while to come back up to speed. This loss is due to crabbing when she is stalled. I race the boat so I pay very careful attention to performance.
I have a sloop and fly a 150% genoa. I don’t know what I’d see with a smaller sail. My guess is that I’d need a bit more wind, but the tack angle should be the same. The sails are relatively new and I have a backstay tensioner.
Rich
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Scott
Why did you replace them? If properly installed I would expect these things to outlive me.I have however been considering replacing the engine raw water intake through-hull. It’s too small and gets clogged easily with weed. I’ve been however reluctant to try to remove it. Access from the inside is difficult. I don’t see any through-bolts. I think the through-hull just threads into the seacock. I have no idea how difficult this would be to remove. Someone would have to hold the through-hull from the outside while the seacock is unscrewed. I see a notch cut into the inside lip of the through hull. I’m guessing that you put some kind of wrench in there. Has anyone removed this kind of through hull and what did you do please?
Rich
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The only issue I found is that in order to prevent obscuring the boat name when folded, I had to make the platform fairly narrow. With the reverse pitch of the transom, this makes it a bit uncomfortable to sit on. If I had it to do over again I’d make it a bit wider and raise the boat name more. It’s also a bit short because the transom isn’t all that wide down low on the transom but there is little that can be done with that.
I have a couple of short wooden steps on the transom that can be used as a step and hold the latches that secure the platform when folded.
I don’t know how the thing would hold up offshore if I got caught in a bad following sea. I tried to make the thing robust enough to stand up to wave action but I’ve had no opportunity to test it. I’d be very reluctant to have a platform that didn’t fold up. I think that would be asking for trouble.
Rich
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Two years ago we were out on the race course when another boat lost her mast. One of the crew fell overboard. We came to assist. The crew of the other boat was unable to retrieve the swimmer. The water was cold and we needed to get the swimmer out of the water before hypothermia set in. Having a swim platform and ladder allowed us to deploy the ladder in seconds and retrieve the swimmer within a minute or two. The guy was cold and wet but otherwise unhurt.
Rich
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Are you sure its not a result of water seeping past the packing gland and wetting the top of the bolts?
Rich
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Tor
I replaced them many years ago, probably around 1995. Alignment of the V-drive and service of the thing in general is easier when you can get a wrench on the bolt, and the walter bolts don’t fit that bill. The RV-20 was designed to handle much larger engines than the anemic 50 HP W60 so I don’t think there was ever an issue with bolt strength. I went to my local hardware store and bought steel socket screws, not stainless. They were black in color. I don’t recall if the box said “case hardened”. As I recall, the lock washers even had to be smaller than normal so I reused my original lock washers. Don’t lose them. They might be hard to match.The RV-26 is a different design and takes a larger bolt. There is room there to get a wrench on the bolt.
Rich
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