Whether you own a Neval 125 or BMW K1000, it’s a tragic and unavoidable fact that eventually it’s going to need repairing. If you're lucky it may be possible to effect a cheap and satisfactory repair as described in issue number nine of the UMG. Eventually, though, a major component like a crankshaft is finally going to expire. If the rest of the bike is in pretty good shape you'll be left with three options. Fit a used engine, pay to have the engine rebuilt or do the rebuild yourself. The first option is fraught with risk and expensive - breakers demand high prices for good, low mileage motors and you only have their word that the engine is OK.
Going to a dealer to have your engine repaired is so expensive that it should be declared a criminal offence. Labour charges vary between £10 and £14 per hour, depending on whether you go to a proper dealer or dodgy backstreet merchant. From personal experience I'd trust neither to carry out a competent job. Also, it seems to be fairly common practice not to replace components that are likely to fail at a slightly later date, so after 2 weeks when the gearbox fails you have to pay for another motor rebuild. This only leaves you with the option of doing the rebuild yourself so that you can check the wear and replace any other components likely to fail. The trouble is, if you don’t do your own servicing, a major rebuild is going to seem a complex and daunting task.
The skills required to strip and rebuild an engine aren’t very great. It’s simply a matter of undoing and doing up things in the correct sequence. That is all a mechanic does. The difference between you and a mechanic is that he can do the work faster. The mechanic will only be paid £3/hour which more accurately reflects the skills involved. After all, a postman gets paid the same. Unless you're severely physically handicapped, there is no reason why you can’t do your own maintenance and even major engine overhauls. It’s mostly a question of attitude, if you believe you can do it, then you can.
It’s best to start learning and building confidence well before anything goes bang inside the engine. Most bikers do some kind of maintenance (except GS550 owners) and many wouldn’t trust a bike shop to change a bulb, but they had to learn the same as everyone else. Learning to work on motorcycles is a gradual process and starts with the basics like just recognising what all the various lumps of metal bolted to the frame are and what they do. The easiest way to learn about your bike is to service it.
This has the added benefit of saving huge amounts of dosh (at least £30 per service) and it gets you used to handling tools. The toolkit that comes with the bike should have most of the basic tools needed but should it not only a decent set of ring spanners and various sized screwdrivers are needed. Add to this a set of feeler gauges, possibly a set of vacuum gauges (about £30) and a grease gun. Next, buy or borrow a workshop manual and you've got all you need to service the bike. The enormous cost saving is obvious and the vacuum gauges can be used to do friends and neighbours bikes at quite a profit.
Follow the instructions in the manual carefully and work at a steady pace, never rushing or forcing anything. Once completed you'll have proved to yourself that everything a mechanic can do you can also do given the time and correct tools. You'll have learnt to undo and do up nuts and bolts, measure small clearances, lubricate things and twiddle a screwdriver whilst watching a set of dials until they all read the same. This is all that the science of mechanics is. You will also have realised what a rip off the motorcycle industry really is.
To give yourself a fighting chance of dealing with a major mechanical problem cheaply, you'll have to be well prepared. What you have to do is provide yourself with the same equipment and facilities as the professional. Obviously, this isn’t entirely possible but you can gather together the basics somewhere warm and dry to work and the correct tools. If you try to sort this out when the crisis strikes you'll be rushed and it'll end up becoming an expensive business.
It's best to have both the manufacturer's manual and a Haynes. The former will give you all the accurate technical info and tell you how the job should be done, whereas the Haynes will tell you how to avoid using expensive and often unavailable service tools. Start to hunt down all the tools relevant to your bike - buy neither new tools which are ridiculously expensive nor cheap ones which can be dangerous (I've still got the scars from a shattered socket).
Good tools last forever so are an excellent buy second hand. Junk shops, flea markets and auctions are all a good source, it’s just a matter of being patient and keeping a list of the tools required to hand. Essentials are an impact driver, relevant sized sockets, ring spanners, universal puller, rubber and hide mallets, long nose circlips and ordinary pliers, screwdrivers and a set of files.
If you know the outer diameters of the roller bearings in the engine then old box and socket spanners can be picked up for a few pence to use as drifts. One absolute essential I've not mentioned is the torque wrench, these are expensive and never available second hand, but can be hired quite cheaply. Most bike shops refuse to lend or hire out service tools or even order them for you. This leaves the choice of adapting an existing tool or making one up from scratch.
I've used a modified broom handle to fix forks to an old BSA; friends can often be talked into making up tools if they work in an engineering factory. It’s also worth lurking around such places as you may find someone who'll do simple jobs for a couple of quid on the side. If you live in or near a large town you can always join a metalwork evening class where the tutor will help you make whatever you want. Attending a car maintenance course is a good way to learn about engines.
The next step is to sort out somewhere warm and dry to do the work. Anywhere is better than the street. Apart from the cold, rain, dirt and dust, you'll probably end up kneeling in dog shit. Ideally you want a workshop that approximates to the one in your local dealers. It should be well lit, spacious with good water and electricity supplies. A garage will normally suffice but a large garden shed can be lit and plumbed in. If neither of these are available a loft, basement or spare room can be taken over the engine taken out of the chassis in the street. Some people use their kitchen as the workshop as the bike fits straight in through the door, there's plenty of hot water, the oven can be used to sweat out bearings and the kitchen table is sturdy enough to withstand anything.
Personally, I think kitchens are comfy workshops in disguise but don't blame me if repairing the bike ends in divorce. A good workshop needs to be carefully thought out, with tools hung on pegboard where they are easily accessible. You need two benches, one to work on and the other to lay parts out on. A low bench with a ramp to put the bike on makes life easier and can be made cheaply from timber. An old electric hotplate is useful for removing bearings and making tea.
Before starting any work, clean the area thoroughly as even the smallest piece of grit can write off an engine. Also, always check out the cause of the defect before stripping down the engine. I once tore an engine apart to replace the rattling main bearings only to find the rattle caused by the clutch - quite normal on that particular engine.
Clean the engine and bike thoroughly before putting it into your clean workshop. If you have the whole bike in the workshop, remove the clutch, primary drive, alternator, top end (where possible) and on old Brits the gearbox, with the engine still in the chassis it’s much easier than with it rocking around on a bench. After all the preparation it’s just a matter of following the instructions and using the right tools correctly.
If a particular tool isn’t available, stop work until you have it. I've seen engine cases written off by idiots trying to lever and hammer sprockets or rotors off instead of buying a £3 puller. If a component seems immovable, you've probably done something wrong or failed to locate a hidden screw. Stop and think before wielding some massive hammer against fragile engine cases. Have a drink, butcher the dog, break down sobbing, do anything rather than lose your temper.
When using home made tools ensure that they are not putting stresses on other fragile parts or engine cases. Use impact drivers with care, if it slips it'll easily shatter Jap alloy. If something seems poorly explained make sketches or take photographs as each component is removed, that way it should all go back together properly. Every part removed should be cleaned, lightly oiled, labelled and stored in a plastic bag with the large and obvious lumps stored on the table.
Reassembly should seem easier as you now have some idea of how it all fits together, but don’t rush. Remember, that you are trying to put the same quality of assembly into the bike as it had in the factory, although owners of British bikes will obviously want to improve upon that. Check and measure all the other parts and replace everything that looks even vaguely worn. It’s a good idea to replace all the needle and roller bearings, which is not as expensive as it sound if you buy all your parts from an industrial supplier rather than a bike shop.
Smear plain bearings with moly paste to avoid wear before the oil pressure builds up. Check that the crank rotates, gears change and nothing feels tight. Always use new oil seals, spring washers, gaskets and circlips. Pay attention to torque settings. As long as you proceed slowly and carefully, never rushing or using excessive force, you should end up with an engine as good as new. You will have saved yourself several hundred pounds and be safe in the knowledge that the job has been well done.
Anon
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