Winter projects ‘98 310

[NamedItAfterYou]

Hello all, now that my inaugural season is done and Applause is on the hard, I’m planning the preseason work for 2027. Some of the items I’m seeing and would like some feedback on are:

A. Keel crack, it didn’t show on the survey and not in the place you’d expect, as we assume a crack on the keel comes from an impact and is at the top of the keel by the hull. This isn’t that. As seen in the picture, on the top of the angled edge of the shoal keel, there is a crack and some separation. What would you suggest?

B. Gauge goofiness. My fuel gauge has shown full all season, though it moves when under way. I was able to add 5 gallons during winterizing so I know it’s lying. Is this just a wire issue or is this a full replacement of the sensor? Next is the rpm gauge, it will read at 3500 when I push it as hard as I dare, but will then go down after a few minutes even if I don’t adjust the throttle. The engine speed sounds the same as well. The sensor is at the back of the engine so I suspect I need to inspect and clean it, anything else I should look for? Bonus question, what speed over ground should I expect at 3500 rpm and no headwind? If there is significant headwind, does the 310 struggle going upwind under power?

C. Cockpit lighting, only the rpm gauge lights up, not the compass, not the side panel with fuel gauge, not the floor light. Assuming I need a bunch of tiny bulbs, does anyone have a list of sizes?

That’s all for now.

 

[JBP-PA]

It's been a sad day in Port Wobegon. This is the first year I've left my boat at the marina, 2 1/2 hours away. I've always brought it home before. I have some canvas projects to do at home, but don't expect to get much done on the boat. My winter canvas is looking shabby in this photo, it didn't seem so bad in person.

 

[Ralph Johnstone]

Maybe I can help as our boats are only a year apart and are quite similar.

A. Keel crack, it didn’t show on the survey and not in the place you’d expect, as we assume a crack on the keel comes from an impact and is at the top of the keel by the hull.

Not being there, that certainly doesn't seem like a crack in the lead keel. Lead in its elemental state is just too soft to crack. My guess is that if you get a chisel or anything else sharp and give it a couple of really good bashes, you'll find it's something other than lead, maybe bottom paint. Remove it and forget it after you smooth out the cavity.

B. Gauge goofiness.

Remove the sensor (whatever type it is) from the tank and see what's going on.

it will read at 3500 when I push it as hard as I dare, but will then go down after a few minutes even if I don’t adjust the throttle.

Something's wrong here ? Do you mean that you can advance the throttle back to 3500 RPM on the tach again and again ? Time to invest in a cheap optical tach and see what's going on under way. Sound like your throttle lever is slipping but that makes even less sense :

Otherwise you could spend a fortune in sensors, guages, etc. and many, many wasted hours. That $24.99 is CAN $.

C. Cockpit lighting, only the rpm gauge lights up, not the compass, not the side panel with fuel gauge, not the floor light. Assuming I need a bunch of tiny bulbs, does anyone have a list of sizes?

With that many failures all at once, you've got to start suspecting the wiring. A common (+) or ground to these lights with high resistance ? Several of those lights are LED and unlikely to have burned out in this time.

 

[Stu Jackson]

Actually, that's a good thing. Why? Because it should lead you to stop, completely stop, using a fuel gauge on a boat and learn your actual fuel consumption in gallons per hour (GPH). This assumes you have an engine hour meter. If you don't, they are cheap and easy to install.

Gauge goofiness. My fuel gauge has shown full all season, though it moves when under way. I was able to add 5 gallons during winterizing so I know it’s lyin

 

[dlochner]

A. Keel crack, it didn’t show on the survey and not in the place you’d expect, as we assume a crack on the keel comes from an impact and is at the top of the keel by the hull. This isn’t that. As seen in the picture, on the top of the angled edge of the shoal keel, there is a crack and some separation. What would you suggest?

You'll need to remove all the paint around the lead to see what's there. Keels are not finely finished castings. Before fairing and painting they are quite ugly. It could be fairing compound or it could be some debris that fell into the casting while the lead was still liquid. My keel had a pocket of casting sand trapped in it. Eventually a little water seeped in and caused it to bulge. Opening up the bulge there was a pocket of casting sand. Cleaned it up and filled it with thickened epoxy. It's been good for 10 years and counting.

B. Gauge goofiness. My fuel gauge has shown full all season, though it moves when under way. I was able to add 5 gallons during winterizing so I know it’s lying. Is this just a wire issue or is this a full replacement of the sensor? Next is the rpm gauge, it will read at 3500 when I push it as hard as I dare, but will then go down after a few minutes even if I don’t adjust the throttle. The engine speed sounds the same as well. The sensor is at the back of the engine so I suspect I need to inspect and clean it, anything else I should look for? Bonus question, what speed over ground should I expect at 3500 rpm and no headwind? If there is significant headwind, does the 310 struggle going upwind under power?

Fuel gauges only give a rough approximation of the fuel level. The least expensive gauges have a float at the end of a lever arm attached to a variable resistor. As the float rises and falls it affects the resistance changes and the gauge shows the resistance as the fuel level. The gauge itself is basically an Ohm meter. The float often becomes fuel logged and no longer floats or the joint in the lever becomes clogged. Easy to replace if you have access to the top of the tank and there are better tank sensors out there. And @Stu Jackson's advice to measure your fuel consumption is a worthy exercise and more reliable than most fuel gauges. It will take multiple fill ups to get a enough data to average out.

Is this a Yanmar diesel? Yanmars use a sensor to count the teeth on the ring gear which is transmitted to the tachometer as an alternating current. The tach head then reads the voltage fluctuations and shows the RPM. The sensor can fail. If you have the shop manual for the engine it will tell you how to test the sensor. Or, the wiring could be faulty, corroded connections or broken wires, or it can be some mysterious force which visits your boat. I have the same issue, the sensor was bad and I replaced it and now the tach works sometimes and sometimes it doesn't. One of these days I'll conduct an exorcism to see if that works.

Cockpit lighting, only the rpm gauge lights up, not the compass, not the side panel with fuel gauge, not the floor light. Assuming I need a bunch of tiny bulbs, does anyone have a list of sizes?

Remove the bulbs to see what size you need. Where appropriate replace with LED bulbs. MarineBeam.com offers high quality reasonably priced LED replacement bulbs for many incandescent bulbs. While the bulb is removed use a Multi-meter to check the voltage and to check continuity in the bulb. If there is no power to the fixture, then you have a wiring problem.

Welcome to the world of boat maintenance.

 

[Indysailor]

The keel crack isn't in a place where I'd suspect an impact or structural issue. Do a little surgery and I'm betting you'll find it's some imperfection in the fairing or gelcoat that just needs a basic repair.

For the cockpit lighting issues, it could be bulbs, but I'd track down the grounds first and make sure they are clean and secure. If possible, rig a jumper wire (e.g. with alligator clips) that you can use to run a light's ground to a known working location. It may be the bulbs, but this is always a good way to start, imo.

 

[rgranger]

Opening up the bulge there was a pocket of casting sand. Cleaned it up and filled it with thickened epoxy. It's been good for 10 years and counting

• Open the crack.
  Using a grinder, carefully open the crack along the red line shown in the photo. Remove any loose or damaged material until you reach solid material

• Feather the edges.
  Feather the surface about 1/2 inch above and below the crack, extending the repair area all the way to the edge of the keel athwartship. The goal is to provide a clean, tapered surface for the epoxy repair.
• Fill the void.
  Pack the void firmly with thickened marine epoxy. A marine epoxy repair putty should also work well. Press the epoxy thoroughly into the opening so that the void is completely filled.
• 
• Shape the repair.
  Cover the wet epoxy with a piece of overhead-projector acetate or similar flexible plastic sheet. Press and smooth the sheet to approximate the original contour of the keel, then tape the edges in place while the epoxy cures. This will minimize the amount of sanding required afterward

• Sand to final shape.
  After the epoxy has fully cured, remove the plastic sheet and sand the repair to match the surrounding keel surface.
• Seal and finish.
  Apply two coats of epoxy barrier coat over the repaired area. After the barrier coat has cured according to the manufacturer's instructions, finish with the appropriate bottom paint.

 

[NamedItAfterYou]

Thanks to everyone for the fine and detailed (!) feedback, wow, thanks! I will definitely do the keel work as you described,
rgranger.

As far as the tank goes, access seems tight, I found the thread (Hunter 310 1997 Fuel tank replacement - pics of aft) discussing getting at and repairing the tank. I'm hoping that getting at the fuel sensor won't be that complicated since some of the primary fuel filter maintenance I've been reading about indicates I will need access to the tank there as well. Unless ya'll have a better time tested way of doing it. Also would like to pump out any sediment in the tank eventually.

The gauge does have a hour meter on it, and since the water body it currently is moored at does not have a diesel dock, I hand deliver fuel from the truck stop. This may be an advantage based on who supplies a better quality fuel? It would be good advice to track fuel burnt/hr (plus rpms ran) and compare that to the Yanmar spec sheet on hourly fuel consumption/hr. That would be a good metric to see how efficient the motor is running and if I can coax more performance out of it. I wasn't excited about motoring upwind and the SOG I was seeing this fall. Winds may have been about 20 on the nose with 1-2' waves and it had me wondering what if the sea state was worse and if the 2GM20F was too under-powered for the boat to make progress. I'll definitely be using the trouble-shooting section in the Yanmar manual in the spring.

A specific question to me (Ralph Johnstone) was if I was repeatedly advancing the throttle and seeing the rpms drop, that would be a no. I put the throttle to where it was reading 3500 rpms and kept it there, the needle eventually went down. And from what I could tell by listening, the motor was running the same speed. So I'm suspecting the sensor has needs, or demonic possession, either way dlochner I know a sailing priest.

Also Ralph Johnstone, I'll eventually ask you about how you were able to get a dodger. Different topic though.

 

[jssailem]

Winds may have been about 20 on the nose with 1-2' waves

Even though it has been said "Gentlemen never sail to windward"


There is no reason to believe this. We tack and jibe to make the boat go where the wind will take us. You might have enjoyed a marvelous time without the motor.

 

[dlochner]

I wasn't excited about motoring upwind and the SOG I was seeing this fall. Winds may have been about 20 on the nose with 1-2' waves and it had me wondering what if the sea state was worse and if the 2GM20F was too under-powered for the boat to make progress.

There are other factors besides engine hp that can have an adverse effect on SOG. Perhaps the biggest factor is the boat's bottom, a fouled bottom will significantly slow the boat down, it doesn't take much growth either. Next up is the prop and how clean it is and if it is sized properly for the boat and engine hp.

SOG is not the metric to assess engine power, STW (speed through water) is the appropriate metric. Sailboats are displacement boats and have a theoretical hull speed which cannot be exceeded by any reasonable means. A 31 foot boat should have a max hull speed of around 6.5 knots STW in flat current free water. If there is an adverse current, which in your example there is, the SOG will be the STW minus the current. In a 20 knot wind with 1-2ft seas a surface current of 1 knot would not be unusual, thus the SOG would only be 5.5 knots. More power won't change that.

Diesels like to be run hard, at about 80% of WOT. At that throttle setting the boat should be moving at about hull speed in smooth calm water. If a more powerful engine is installed the boat will reach hull speed at a lower throttle setting which is not good for the engine.

 

[Ralph Johnstone]

I put the throttle to where it was reading 3500 rpms and kept it there, the needle eventually went down.

Putting that fine point on it, I'm going to say it's the indicator that's gone _ _ _ s up. I swapped my original tach indicator after about 15+/- years over to a VDO Vision Series 333-163 which has probably changed its part number since then. The reason for that choice is that it's programeable and will accept any output imaginable from your sender. I still suggest the optical tach before spending too much money before knowing exactly who's at fault here. Also helps with the final trim to the last RPM. Oh, and the VDO indicator is the same diameter as the original factory installed unit so a perfect fit.

This may be an advantage based on who supplies a better quality fuel?

Truck stops always has the better (cleaner) fuel due to a faster turnover.

I'm hoping that getting at the fuel sensor won't be that complicated

Access to the top of the fuel tank for the level sender, filler hose, vent hose, engine supply hose, and fuel by-pass return, is through the aft lazarette and the aft floor panel in the compartment. A panel about 8" X 12". A bloody #%$^&*@ pain to reach into with one hand but it's the only way to get in there without destroying your rear cabin panelling every time you want to check something.

It would be good advice to track fuel burnt/hr (plus rpms ran) and compare that to the Yanmar spec sheet on hourly fuel consumption/hr.

I'd be inclined to skip that exercise for now. What you want when you're far from civilization is "HOW MUCH FUEL IS REMAINING". The rest is all very nice and interesting but record a wrong number somewhere or have your engine start gobbling fuel for whatever reason and you're up creek without a paddle. And in our lonely, freezing northern waters not a good idea. Mind you, having said that, I do have a wooden backup measuring dowel which I use to check the fuel level every 4-5 or longer years.

​

The 3/8" FIP hole also gives us access to pumping out the tank using a Pela engine oil vacuum pump.

some of the primary fuel filter maintenance I've been reading about indicates I will need access to the tank there as well.

Huh, what's that all about ? You don't maintain your primary fuel filter, you replace the filter element when needed. If it needs it too frequently, you want to check the quality of fuel in the tank for biological contamination. There is no way of accessing the fuel without a small access hole as shown above.

Don't get talked into a large inspection hole in the top of the fuel tank. With a full tank and rough seas, you've got a recipe for a fuel leak. And you don't want leaked diesel fuel down there as human access is impossible without that butchered aft panel again. Treat the fuel with BioBor and stop the problem before it gets started.

I wasn't excited about motoring upwind and the SOG I was seeing this fall.

You and everyone else with a 310. No doubt about it, the 2GM20F is slightly undersized for that weight and size of boat. A minor setback for a lot of advantages.

PM me as I'd like to know about your diesel fired heater if you have one.

 

[Stu Jackson]

True about knowing what's left. I'm sure you can find the capacity of your tank somewhere on the internet. If not, measure the outside of the tank and figure it out. My tank has 23 gallons, but i always used 20 as my fill up max leaving 3 gals or 6 hours of operation as a reserve. Your boat, your choice. But without knowing fuel consumption AND tank capacity, you won't know.

I'd be inclined to skip that exercise for now. What you want when you're far from civilization is "HOW MUCH FUEL IS REMAINING". The rest is all very nice and interesting but record a wrong number somewhere or have your engine start gobbling fuel for whatever reason and you're up creek