Bodging allows a repair to be effected to a motorcycle for either zero or minimal cost. It's the art of converting whatever's close to hand into a useful instrument of motorcycle renovation. The obvious corollary is to never throw anything away, however unlikely it may have some future use.
Those who insist on trying to look inside Jap engines will immediately become aware of the need to start bodging. The unfortunate use of mickey mouse metal for engine screws, combined with corrosion between the aluminium engine cases and steel screws and the effect of the screws being tightened down with huge pressure and speed, means there's a very good chance that at least one screw holding down an engine case will break off, bend or tear out the aluminium half of the screw thread. This assumes that your toolkit extends to the luxury of an impact driver, for if a small chisel and large hammer are employed the chances of mishap (not to mention bloody fingers and slaughtered cats) are much higher.
There are any number of ways of repairing thrashed screw threads. If you insist on behaving like an engineer, you can have the thread drilled out and Helicoiled - something the Japs should have done in the first place, to protect their cheap and nasty alloy. It's sometimes possible to drill the hole and re-tap for a bigger thread size. Much easier, though, is to clean out most of the dirt and oil, apply some Araldite to the remains of the thread and to a new screw. This is not particularly recommended if the screw has to take great stress and its effectiveness depends on how much thread remains in the alloy. To avoid problems when undoing the bolt smear a very thin layer of oil over the bolt.
I've used this method on many engine bolts and even on the camchain tensioner bolt. A very common problem occurs when removing exhaust headers, when undoing the bolts that hold the exhaust fins in position one or two bolts refuse to move, corroded in position, even extending the leverage of the socket wrench with a steel tube fails to budge the bolt - until it suddenly snaps off flush with the cylinder head. Such things as stud extractors will often snap off inside the bolt, compounding the problem rather than solving it. The solution is to drill a hole in the bolt, tap in a thread for a slightly smaller bolt. If any bolt really does refuse to budge or break, then soak it with one of the proprietary release agents, leave for an hour or two and try again. In many circumstances problems that appear insurmountable at first can be solved later on if they are forgotten and reassessed after a cup of tea.
In the long run, it's much better to walk away than start whacking valuable alloy and steel with a massive hammer, however much the recalcitrant beast asks for it. One of the nastiest places for the thread to strip is the spark plug thread. Araldite may work as a strictly temporary repair (like ten miles), it really does have to be Helicoiled. It's also quite easy to cross thread the plug, especially if it's inaccessible. I've found a little bit of oil on the thread helps and use of Jap spark plugs improves the chances of fitting the plug properly.
One of the most common problems with Jap engines is early wear of the camchain tensioner or camchain. Certain bikes just have plain bad design and there's little that can be done, save fitting the latest version of the tensioner. Certain tensioners can have their lives extended by inserting a bit of metal between screw and tensioner (don't blame me if it disappears into the depths of the engine) or using a longer screw. Camchains can usually be changed without stripping down the engine using a link that can be riveted in position. The old link can be filed or drilled off (given that you cover up the rest of the engine internals), the new chain connected to the old with a split link, the engine slowly rotated until the old chain is thrown out. Throw away the split link and rivet the new one in position with a large hammer supporting the rivet and a small ball hammer contouring the head of the rivet. If you don't support the link properly you'll end up wrecking the camchain sprocket.
Rebores can often be avoided by buying a set of rings and a honing tool to smooth out the bore (they attach to the end of electric drills), although these useful devices have disappeared from the market. I once ran a bike on an old set of pistons with oversize rings and a rebore, and it still went OK, so anything's possible. The main cause of early camshaft bearing failure is lack of frequent oil changes. When the bearings are the cylinder head surface, the choice of repair is between finding a good head from the breakers or having the old bearings bored out and either plain or needle roller bearings fitted. The main problem here is to make sure everything lines up OK, and this depends on how well the machining is done, and it's not something that I particularly trust.
Both camshafts and crankshafts can be repaired by specialists, but this is way beyond the home bodger and most Jap engines that need crankshafts rebuilt will be so far down the path of dereliction that they really can't be run on the minimum of money.
Many so called sophisticated Jap engines use hyvoid primary drive chains, although tough by normal chain standards, there's never any way to compensate for wear, save for a complete engine strip and replacement. Clutch life can often be extended by stripping down, roughing up the plates and cleaning up any burrs on the clutch drum. There are lots of relatively cheap clutch repair kits available from pattern part suppliers.
On older Jap engines, clutch pushrods are either bent or broken or scarred by the nearby final drive chain. A piece of silver steel tube with one end rounded off with a file lasts quite well. The clutch pushrod seal is frequently ruined by the dirt thrown off the chain, allowing surprisingly large quantities of oil to escape from the engine. Fortunately, it can be pulled out and replaced without splitting the engine. As they are often difficult to buy from motorcycle shops, run down to the nearest bearing shop to see if they stock the same seal, it'll also be that much cheaper. I always use a spark plug socket and small hammer when fitting these seals, as the socket is just the right diameter to support the outer edge of the seal and drive it in squarely. But buy two seals as there is a certain knack to it, and it's easy to destroy a seal if you get it wrong. If the seal keeps falling out, smear a little bit of Araldite on the outer edge.
Finish off by coating the pushrod and seal in thick grease for future protection. If you can afford it, replace all engine bolts with Allen screws and any other bolts with either stainless steel or chrome plated items. It makes future maintenance so much simpler that it's well worth the initial expense.
Probably the first thing to go on modern bikes will be the exhaust system. The header pipes will start to rust after a few months winter riding. Copious elbow grease with chrome cleaner is the only answer. Because these pipes are double skinned (rather laughably to stop the outer pipe turning blue) they will last for a very long time before actually falling apart. Once all the chrome has disappeared they can be cleaned up with a wire brush and painted with heat resistant black paint. If you care about the appearance and want to keep the bike for a long time, there are companies that will bend up stainless steel exhausts, the only real solution to rusty exhausts. Silencers are another ballgame. Moisture from the combustion process collects inside the exhaust system and rots away the silencer from the inside out.
The first sign of decay will often be a loose baffle. The silencers can crack around their circumference - try two Jubilee clips and a piece of sheet steel wound around the exhaust (or Coke can cut up into a piece of sheet metal), a surprisingly effective cure, I once repaired a silencer that was hanging on by a mere inch of metal. Holes in the metal can be filled with Gun Gum, wrapped with exhaust bandages or welded over, although Gun Gum often only has a life of one or two weeks. Collector boxes suffer similarly and usually have the benefit of being well hidden away, so can be filled, wrapped or bandaged with impunity.
When the silencer finally fails, the complexity of some four-into-two systems means you're supposed to replace the whole system at a cost of several hundred pounds. Much better, to saw the silencers off and replace with either a set of Universal items or something out of a breaker. It's also possible to cut off the ends of silencers that have degenerated into straight through systems, make up some end caps with baffles Araldited in position and the new end caps riveted onto the old silencer. Sounds awful, but gets a few more months life out of the exhaust.
Those really desperate to save money will just bung some likely looking metal tubes on in place of the decrepit silencers. This probably won't impress Mr Plod or all those citizens sticking fingers in their ears as you growl past; it'll also probably overheat the engine and burn holes in pistons...
After exhausts, and for no good reason, alternators are the next most likely thing to give trouble. Here, the problem is often made worse by infrequent oil changes that allow the engine to run too hot, overheating the alternator in turn. Fortunately, alternators can be rewound relatively cheaply, from £25 upwards. It's just a pain in the arse to strip down and takes the bike off the road for a few days.
The alternator probably won't fail immediately, it burns out one set of coils first, decreasing its power output. It may be possible, on some electrical systems to wire in the coil for the lights (that's normally only switched in when the light is turned on) to increase the power output, which is fine as long as you don't ride too much in the night. As soon as the alternator starts to play up it'll take out the regulator and rectifier. Or vice versa on some bikes.
Both of these components are horrendously expensive to buy new and dodgy to purchase second hand (I know at least one breaker who insists that you swap over the old component and won't give a refund if it doesn't work). The solution is fairly simple in theory, but can be difficult to enact in practice. Buy units used in cars. In effect this means you'll have to visit dozens of car accessory stores until you find one that recognizes the words rectifier and regulator. Your reward will be minimal cost (£3.50-£4 each) and components that are designed to handle much more power, so should last that much longer.
The other problem is that the rectifier will need leads soldered in position. Also, 4 because these rectifiers are supposed to fit inside car alternators, the diodes are left exposed when mounted on motorcycles. I've found mounting the rectifier on the battery box a good idea because it's already rubber mounted. According to some strange theory of electronics the voltage regulator has to be matched to a particular alternator and there are dire warnings about fitting non-standard regulators, but as the alternator will probably be rewound anyway, this shouldn't be taken too seriously - I've fitted a car unit (just a small electronic black box, not one of those massive mechanical regulators) without any ill effects to a Suzuki GS550. And reports have reached the UMG that other people haven't had any problems with other bikes. Studying the circuit diagram for your particular bike should sort out which wires to fit to which rectifier/regulator lead.
Bike batteries are another contemptible object that last for ridiculously small mileages and cost outrageously large sums of money. If at all possible fit one of the small car batteries. Some old British bikes will run without batteries because the manufacturers took the care to make sure that the alternator supplied the current exactly when the points needed it. Most Jap bikes won't run at low revs without a battery. Fitting a large electrolytic capacitor in place of the dead battery will provide enough energy storage capacity to allow the bike to run at low revs. This won't let the electric start work and has a limited life, but capacitors (18V, 10,000uF for 6 or 12V systems) can be bought for £1 to £2 from electronic component shops. Beware, though, if either the regulator or rectifier aren't working properly, either excessive voltage or alternating current will be fed straight through to the electrical components.
Again, things like point's condensers, headlamps, some contact breakers (you can even alter car units to fit if you're feeling really energetic), some switches and various other bits can be bought from car accessory shops, or better still scavenged from car breaker yards.
Chrome mudguards can be repaired by filling the holes with Isopon, rubbing the suface down with sandpaper and doing a quick respray to the whole guard. Many bits can simply be thrown away when they stop working: indicators, centre stands, mirrors, etc. Although useful, they are not essential. A couple of links can be taken out of the drive chain, then leave it to soak in old engine oil overnight and work out any tight spots that still remain. Not recommended for fast and heavy bikes, as it'll probably break, but OK for the smaller, slower stuff (although anything beyond two links is just asking for trouble).
Cheapo suspension mods are limited to sticking valve springs in the front forks to make them stiffer, and thicker oil to improve the damping, although the latter does assume that the seals are OK and’ that they're not going to burst under the extra pressure of the increased damping forces. Rear shocks usually can't be stripped down to put new seals in the damper units, whilst the usual result of trying to change the springs is much physical damage to the person foolish enough to play around with wound up springs. On twin shock bikes, the stud that holds the top of the suspension occasionally falls off due to corrosion, on some frames its remains can be drilled out and a high tension bolt fitted - but don't come running to me if this fails when you least expect it. Mono-shock bikes suffer from excessive wear of most of their linkages. Some of them can be drilled out so that a plain bush can be whacked in, but do make sure there's enough metal left for the stresses in a swinging arm.
Old inner tubes can be cut up and used to rubber mount electrical components that suffer the effects of vibration. Especially useful on some fours where high frequency vibes keep blowing the rear tail light. Inner tubes can also be effective when the mountings on petrol tanks have worn with age. By wrapping the inner tube around. the frame tubes, the petrol tank has a tight. fit and stops wobbling all over the place.
A common problem on old bikes is leaking petrol caps where the old gasket has worn down - with a full tank the fuel just spills straight out. Cut an inner tube to suit, making sure to keep the air hole clear, and it should clear up the problem.
The safety aspects of tyres precludes doing anything too silly. Large tyre shops often have tyres that have been swapped before they're down to the limits (sometimes with as much as 3mm left) and they sell these off for a few notes - although, personally, I find changing tyres such a pain that I always opt for new tyres.
Again, the safety aspects of brakes means I always avoid any major modifications. Some disc calipers can have the sliders replaced with shouldered studs to ease disassembly, whilst some drums can have the actuating arm lengthened or shortened to increase or decrease braking force. On smaller bikes, it's often cheaper in the long run to throw the whole disc front end away and fit a drum set up, such is the relative lack of maintenance inherent in such a move.
Modifications to the carbs will depend on the kind of device fitted to the bike. Slow running and float height adjustments are available on most bikes. Raising the needle by inserting a washer at one end where it's located is possible on many types, whilst drilling out jets is only for the very brave. CV carbs will often rot their diaphragms and equivalent car units may be available for some bikes.
One of the most devious problems occurs when a small crack appears in the rubber manifold (I once stripped an engine down because I'd missed this), letting the engine run lean. As a temporary move apply some puncture repair glue and bandage with an inner tube and couple of Jubilee clips if the crack is reasonably placed for such action.
The list goes on, but bodging is not an art instantly developed, it's something that's picked up over time and with experience. Some of the lengths people go to avoid paying money to keep their, er, pride and joy running defies immediate comprehension, but it often works quite well, costs next to nothing and gives them something more interesting to do than watch the TV on wet and cold nights. The bottom line is that it's good, clean fun.
Bill Fowler