Maintenance and modification to a Beneteau First 31.7


Everyone who has ever sailed on Rhythm in blue agrees: "It's a great boat!"

But, any boat is a compromise and any new boat can be made better. Here a few things we have found and fixed with our Bendytoe...

The Throttle Key Failure
This is a story of "a good idea, but wrong choice of materials."  The removable engine throttle key is a racer’s boon. No more spin sheets snagged in the throttle lever. The Spinlock key and socket is well designed. The TFX throttle control box, hidden inside the cockpit locker, is also a good design. The Spinlock unit is a socket which fits over the TFX spline. But, they are two different kinds of alloy. The Spinlock unit is a hard alloy, the TFX is a soft alloy. With use, the TFX spline wears and, after a time, the Spinlock socket no longer grips the TFX spline. Which means the throttle key spins round and round, without engaging or disengaging the engine in forward or reverse. This is a serious problem if the engine is in full ahead when the spline gives up the ghost and neutral or reverse are no longer available.

Fortunately for us, the unit failed outside Howth Harbour, at the end of a race, when the crew were lowering sails to motor in to the marina. When engaging forward to keep the boat head to wind, the Spinlock unit spun and spun. The crew shut off the engine, raised sails and called HYC for a tow to their marina berth.
We elected to replace the whole lot with a new Volvo throttle control box and permanent control lever.

We are aware of one other 31.7 whose throttle key failed just as they arrived at their marina berth and attempted to select reverse. It failed and "thump...." We are not aware of any Beneteau plans to replace or modify the unit. We understand the unit is used on all First xx.7 boats. Take care!

Loss of coolant
This is a story of "factory savings of a few francs nearly blew up the Volvo." The Italian-made (Quick Italy) hot water calorifier is located in the cockpit locker. It heats hot water either with an electric element from shore power or from hot coolant passing through an internal heat exchanger. The hot coolant leaves the engine, is piped to the heater, then back into the engine. This is a good plan: free hot water whenever the engine is running, enough for three quick showers.
A coolant drain stopcock is located at the bottom of the engine block. Because the hot water tank is a little bit lower, it has its own coolant drain stopcock, with a clear plastic pipe attached to it. On early models, the stopcock is a sturdy bronze threaded twist stopcock. It needs five or six full turns to open. Safe and sensible.

On our boat however, and others from at least 2001 onwards, the bronze stopcock has been replaced with a cheap and nasty lever valve: horizontal is closed, vertical is open.

The plastic drain pipe is still attached.

This change of valve produces a construction savings of perhaps 60 francs (10 euro) per boat. So, what has this to do with blowing up the Volvo? Here is what happened on Rhythm in blue:

At the end of a day of sailing off Howth, Pat, the skipper/instructor, started the engine whilst dropping sail so as to motor in to the marina. After a few minutes, he noticed "an unusual smell of something hot burning. There was no smoke, but it smelled wrong. We shut off the engine, hoisted the main, and sailed around for a bit." . Pat went to the engine, took off the coolant cap and peered inside: no coolant. Because it was winter time, and the boat was sailing only on Sundays, the main domestic water tank was empty. But, he had most of a 5 litre jug of Ballygowan Spring Water on board. He poured in a bit of Ballygowan, then a bit more, then a lot more before the coolant tank filled. He then cautiously started the engine, sniffed a bit, smelled nothing amiss and motored to the berth. The Volvo was saved
As part of our standard procedures, Pat lifted the floorboards when tied at his berth. A sensible chap, Pat reported the engine problem to one of our engineers and added: "There was a bit of water in the bilge, it looked funny, so we sponged it out. No, we didn’t taste it to see if it was fresh or salty." The engineer went to the boat the following Friday and found the coolant tank was empty, again. And, there was water in the bilge. The engineer is a hardy type who always tastes clear bilge water. It was fresh water, but it had rained during the week, and rain water runs down the mast luff track into the bilge.

Our man re-filled the coolant tank, started the engine, had a smoke while it warmed up, then ran the engine at 15,000 rpm for a few minutes. When he checked the header tank: no coolant water. Hmmmm. He filled the tank again, started the engine, ran it at high revs and looked for leaks under the engine block. Nothing, dry as a bone. But, he could see water trickling into the bilge. And, it wasn’t raining.  He traced the trickle to the cockpit locker and found the hot water tank drain was open. All of the engine coolant was disappearing into the bilge. While sailing the previous week, something had shifted in the locker and knocked the drain lever to the open position. While sailing, coolant had drained out of the system. When Pat started the engine, the coolant system was dry, the new engine overheated and gave off a bad smell, which caused Pat to shut down and investigate, sensible chap. The Volvo was saved.

Our solution was to wire the valve closed, wrap the closed valve with insulating tape, and bend the plastic drain pipe back on itself and tape it shut. To be sure to be sure to be sure.

This few francs savings could have caused the engine to blow. We would have gone to the dealer, who would call in Volvo, who would say "not our fault, go back to Beneteau" and our boat would have been high and dry for ages. It is possible a similar valve is fitted to all First xx.7 boats.

Fiddling About
In the cabin, there are three storage lockers with hinged outward opening doors: one over the fridge, and one each on port and starboard, above the saloon seats. When the doors are opened, the top shelf is exposed, but the shelf has no fiddle. Thus, anything on the top shelf falls out when the door is opened.
We made simple fiddles using mahogany rounded parting bead. Parting bead is used to separate sash windows on houses, and is available in 2 metre lengths from any builder’s merchant. Don’t use softwood parting bead which will rot. To fit the fiddles: cut the parting bead to length with a small panel saw, drill four 2mm holes in the shelves, fit the fiddles and screw up from underneath with 2.5 x 25mm zinc coated SPAX screws and a battery drill.

Forestay clevis pin
The stainless steel clevis pin which connects the forestay to the stemhead is over long. When the rig is tightened, the pin adopts a slight angle under stress. We packed two stainless washers under the clevis pin head and two more on the outside before putting on a new split pin. The clevis pin now fits snug and tight.
Also, the dealer who prepped the boat had installed the pin with the split pin on the inside of the stemhead bow roller. Anchor chain passing over the split pin would have eventually snapped it off, the clevis pin could have wiggled out, the forestay goes slack and goodbye mast. Dumb.

The navigator’s seat will fall apart The moulded seat  fits snugly onto a pair of upright timber panels, set ninety degrees to each other. Each panel is held in place with a pair of self tapping screws to the heads bulkhead and to a small bulkhead under the nav table. Lift the seat and there is a small storage locker where we keep the lead sounder, a Dutchman’s log and a large torch. After a year of use, with navigators using the seat in strong winds, heavily heeled, the two panels came away from their bulkheads. We used M6 nuts and bolts to thru- bolt the seat from inside the head. Getting under the nav table to do the same required a skinny guy with a double jointed left arm to fit the bolts.

The companionway steps
The steps are a moulded grp unit that is lifted away to access the engine. When the steps are in place, a pair of exceedingly cheap 6mm shoot bolts drop into holes drilled in the cabin sole. The shoot bolts are so cheap that one broke on a demonstrator boat at the London Boat Show.

After a bit of use, the steps begin to wiggle, the shoot bolts enlarge the holes in the sole and the steps unit becomes decidedly unsafe.
We cut two pieces of 3mm aluminium plate and filed an indent along one edge to take the 6mm bolts. We then screwed the plates to the sole and they serve as stops, preventing the bolts from enlarging the hole and keep the steps snug in place.
We also stripped off the useless self adhesive timber-effect vinyl pads on each step and applied non-slip deck paint in their place. No more slippery steps.

Liferaft
Rhythm in blue carries a six man SOLAS B canister liferaft. Although there are fittings for a raft at the aft end of the cockpit, ours wouldn’t fit under the tiller. In that location, it's a definite trip hazard. To launch, somebody would have to slide it out from under the tiller and then lift it up and over the transom.

We discovered a pair of lengthways stringers are moulded into the underside of the coachroof. We mounted a pair of teak rails on the coach roof with stainless self tappers into the hidden stringers. Then we mounted a stainless raft bracket onto the teak rails. The raft sits high on the coach roof, with just enough clearance for the kicker to pass over it.  In an emergency, it will be easy for someone to slide the raft off the roof and over the side of the boat.

Boom Tack Fitting
The mast and boom are made by Spar Craft in France. They are quality spars, but the boom tack casting is, ummmm, a bit agricultural compared to competitor Z-Spars. We didn't check the casting and it was a bad one, with a small internal crack which, of course, became worse and then crunched and failed during a February weekend cruise to Wicklow. Another item added to the list of "check once a week for problems."