Now then, I’m no saint when it comes to looking after my equipment. I’m sometimes late on service intervals and have been known to buy cheaper non original parts in order to keep my elderly vehicles on the road for (yet) another year. There does come a point however, when economy becomes false economy, so even when I’m really busy I still make sure my kit gets the attention it requires.
What I mean by this is that it’s possible to exist under the illusion that by not bothering to have your car, van, boat engine serviced properly for a number of years you can save a worthwhile amount of money on oil, filters and labour. The truth of the matter is that all the time you are saving money on these cheap consumable items, there is a debt of mechanical pain being inflicted upon your motor that will eventually both let you down and cost you a flipping fortune. If you regard your vehicle as a cheap throw away item and it’s easily replaced by another cheap throw away vehicle then this is really no massive problem. If, on the other hand, the motor in question is installed in a boat that you take out of safe waters and into the sea, well, I feel you really are pushing your luck a bit.
Let me give you a recent example of many I have seen during my previous occupation repairing old, knackered machinery. Its a very, very common problem and it starts like this:
Let us assume we are talking about a small boat with a two cylinder engine. The engine is installed in a rather inaccesable place, it’s bloody awkward to get up over the top and therefor the fiddly task of checking the valve clearances gets skipped on repeated services. After a while the checking of the valve clearances is forgotten about completely as it doesn’t seem to make any difference to the running of the engine anyhow so clearly the job isn’t necessary. The engine gives no rattles or outward signs of there being any problem apart from maybe a greater reluctance to wake up on those cold spring mornings. One day, most likely when you need the thing the most, it simply refuses to start at all or if it does, it chuffs and wheezes along with all the enthusiasm of a small child going to the dentist. It has lost a cylinder. You might be able to limp along for the rest of the sailing season on one cylinder if you choose your days out wisely, but you’re more likely to want to know what the problem is.
This is when it starts getting expensive. With many boats it’s going to begin with a crane out into a yard and a period of storage (fees) while learned folk poke your ancient motor with gauges whilst mumbling about compression being down and access being difficult. Then, somehow, the top of the engine will have to come off in order to confirm the likely diagnosis. The boat will then get shunted into a distant section of the yard for a period of weeks (more storage fees), while a world wide search for the required obsolete parts and gaskets is launched. This will eventually result in a piece of paper landing on your doormat with a quite incredible estimated repair bill. You’ll have to do it because otherwise you can neither use or sell your boat. By the time the work is done and your boat is back in the water, most or all of the summer is gone, you haven’t got any kidneys left to sell and your sailing season has worked out to be the most expensive one on record . But none of this would have happened if only those valve clearances had been checked.
As any engine is used, a gradual degradation of the metal valve seats by the super heated exhaust gasses is going on all the time. It is faster in some engines than others, indeed I know of a few owner/servicers who boast that their valve clearances never change over decades. Great, but why not check them anyway. As the valve clearances reduce, the engine will very gradually lose power due to the slight change in opening/closing times of each valve. When the clearances get really tight the engine will become harder to start due to the actual loss of cylinder compression through valve leakage. If left unchecked, the valve seats will erode very quickly and give a missfire or in extreme cases the escaping hot gasses can melt or split the valve and drop bits of metal into the fragile inner workings of your engine (see photo). This is a bad thing.
I’ve always looked after my own vehicles; all cars, vans, motorcycles and boats of a very elderly and well used type. I can count the number of times they’ve let me down due to mechanical failure over 26 years on my fingers (mostly that wretched old Mercury 7.5 I first had on “Macavity”). That’s not at all bad really and the key is regular, vigilant servicing. So, Christmas is here, you’ve got a few days off, why not escape the mayhem for an afternoon with a bag of spanners and treat your boats old motor to a bit of festive lovin’. Yule be glad you bothered come the Spring. Merry Christmas everyone.