LOTS OF WIRES BUT NO REVS WEB Q&As
QMy BMC 1500 engine’s original rev counter currently has no wires anywhere near it. Made in 1979, it has three terminals marked ‘Pos’, ‘Neg + Gen Z’ and ‘Gen X’. There is a label saying ‘022’ adjacent. Any ideas for wiring it? PETERI, via the CB website
ATONY REPLIES: I have a feeling this rev counter may have been designed to be paired with an inductive sensor, often fitted close to the front pulley or flywheel.
If I am right, the ‘Gen X’ and ‘Gen Z’ would be fed from the two sensor connections (with ‘Pos’ connected to the ‘ignition on’ terminal on the ignition switch).
As the inductor’s output is similar to AC, it shouldn’t matter which of ‘Gen X’ and ‘Gen Z’ goes to where – but if it doesn’t work one way,
QAREPACKING THE STERN GLAND
Can you repack a stern gland with the boat in the water? ELLAN1019, via the CB website
TONY REPLIES: Yes, it’s usually done that way. Prepare your packing, have all the tools you need to hand first and be aware that the degree of water leaking into the boat depends upon the wear in the shaft and bearings.
If there is only a little wear then using the greaser before you remove the old packing may seal the shaft completely. If there is a lot of wear the water ingress could be a little worrying the first time you do it but the bilge pump should cope. try the other. I have also seen rev counters with their own little generators fitted to the engine in which case the two Gen terminals are fed from the generator.
If your engine does not have an inductor you could try feeding Gen X from the W terminal or a phase tap on the alternator and connecting ‘Neg + Gen Z’ to negative – but bear in mind that whereas modern counters have an adjuster to set the correct speed (because the alternator pulley ratio is unknown to the rev counter maker), an inductor sensor would run at engine speed – so a rev counter designed to work with it may have no adjuster.
It could save time and cost to buy a modern counter and feed it from the W terminal.
QHOW MUCH TO FIT A STOVE?
Leaving aside the cost of a stove, what can I expect to pay to have it professionally fitted to a narrowboat. PHATMAL, via the CB website
ATONY REPLIES: That depends upon the local labour rates, and how much work is required.
Does it requires piping to central heating? How much work is needed to clear a suitable space and fire/heatproof the area and install a hearth (which depends upon the stove to a degree)?
It could be anything from maybe £200 for a simple installation into a ready made space to £1,000-plus.
Once you have decided on which stove you want, talk to some boatyards for a quote, but they will probably want to see the boat first and then discuss the job.
QLAUNCHING ON THE MON & BREC
Can I take my own small boat on the Monmouthshire & Brecon Canal and if so, where can I put it in the water?
WITHERM, via the CB website
ATONY REPLIES: Unfortunately ‘small boat’ could be anything from an inflatable dinghy, through canoes and rowing boats to a smaller powered craft. This means I cannot give a straightforward answer. The boat will need to have a Canal & River Trust licence (except for current members of British Canoeing and Canoe Wales, who get to use the canals for no charge as part of their membership) and insurance. If it is powered by an inboard engine or has certain equipment (such as an electrical system) it will need a current Boat Safety Scheme Certificate. Assuming it is not one that you can simply lift in and out at the canal bank, the boaters’ guide available on the CRT website shows slipways at Llanhamalch, Pontymoile and Goytre Wharf. You may have to pay to use slipways at boatyards.
CAN I FIX THIS MYSELF?
QMy 1985 Volva Penta AQ 125A runs at a high temperature once warmed up. I have been told the pump for the fresh water cooling system needs replacing. Is the procedure too technical for a non-professional? How difficult would you rate this job on a 1 to 10 scale? TOD LACY, via email
ATONY REPLIES: Unless the fresh water pump is leaking I would question that diagnosis. Exceptionally rarely the impeller can fall off the shaft, in which case it would boil within five to ten minutes.
I suspect a sender mismatch (if you mix U.S. and EU standard gauges and senders, the gauge will read either half as hot or twice as hot as the true temperature) or a raw water volume problem rather than the pump.
If this is a heat exchanger engine, ensure that the heat exchanger and any oil cooler cores are not blocked on the raw water inlet side. On a wet exhaust engine, check the exhaust mixing elbow is not partially blocked by scale and corrosion and that the exhaust hose is not delaminating and blocking the exhaust.
If the pump does need changing, as long as there is sufficient clearance between the front of the engine and any bulkhead, on a typical engine I would rate the job about 2 or 3. The general procedure is as follows: • Drain antifreeze. • Slacken any bolts holding the water pump pulley on. • Remove the drivebelt and pump pulley. • Remove the bottom hose. • Remove the (typically 4 to 6) bolts or nuts that hold the pump onto engine. • Grip the pulley flange and waggle the pump to free and remove – it may well stick on the gasket. • Clean the engine face. • Refit pump with a new gasket.