Thursday, 21 January 2016
Kawasaki KH250: DR hack
Mixed pleasures, trying to ride the ancient Kawasaki 250 triple rapidly. The engine could still sing a song, aided by some heavenly spannies, but the chassis was all wrong. The geometry wasn't exactly inspired when the bike came out of the factory, add in a couple of decades of abuse, the result was best described as wanton. As in going in and out of frightening weaves in an entirely random manner.
I tried to check the wheel alignment out using a plank of wood but didn't get very far. Left all confused by the different sections of the tyres. Didn't look too far out, anyway. The rubber was pretty dubious Far Eastern stuff that could turn nasty on wet roads but there was plenty of tread. I suspected most of the problems were caused by the forks as they lacked any kind of smoothness in their action and often seemed to stick.
Bumpy roads had the front end going off on its own unique joy ride. The only surprising thing was that the bars didn't go right out of control. After the initial couple of weeks I began to realise that if it felt like the chassis was falling apart, the wobbles didn't develop into something really deathly. Impossible to ignore the front end's machinations but actually quite safe to ride flat out when the circumstances allowed.
Having failed to blow the motor up in the first month, despite revving the engine flat out everywhere, I opted to fit a GPz305 front end. I just happened to have one laying around the garage after exploding the vertical twin's motor. Didn't take much effort. The GPz's forks aren't exactly huge but the twin discs would surely come in handy, the old single disc on the KH never working very well. They didn't exactly go straight on but after machining the yokes I was set for the test ride.
All was well up to about 75mph when the most alarming speed wobble imaginable went down. I almost went down as well, the bike threatening to bounce right off the M4. At least the discs worked properly, hauled the speed right down in an instant and basically saved the day. An act subsequently repeated many, many times.
Not really wanting to be limited to 70mph in my daily excursions, I gave the front end another look over. Some very minor slack in the lower yokes. Loosened off the clamps, filled with Araldite, tightened up and waited overnight. It was with a very tentative right hand that I hauled the KH up to 75mph and was very pleased with myself when it continued to yodel all the way up to the ton with nothing more than the odd bit of weaving. In the right circumstances, 105mph on the clock wasn't impossible and 85-90mph cruising quite feasible (if you were an Arab sheik - see later!)
Turned out to be a rather splendid bike once the front end was sorted. Spirited, fast enough for modern roads and able to whizz-bang through most circumstances. Part of its charm was the way it went through spark plugs, oil and fuel... that's what I kept telling myself, anyway, and the small garage owner nearby always grinned widely when I pulled in to stock up on these essentials. It's probably possible to get 40mpg and 100mpp but the low revs involved will invariably gum up the spark plugs, so the unlikely expense will get you that way instead.
The good side of the triple was its unique exhaust note - a real spine chiller - and its wacky appearance that shouted style and power. At best, the handling was adequate, at worst it would get rid of constipation pronto. Pillions usually got off all white-faced, looking for somewhere to throw up. Well, the rear shocks were original fare but still up to solo riding - I guess Kawasaki just bunged on stuff off their larger triples and it worked well when new. The 250 always had the reputation, in later models, of being the triple that actually had a passing stab at handling.
Into month three of ownership, the 34000 miler began cutting out, refusing to start and threatening to burst into flames whenever I turned on the lights. Some of the wiring in the alternator was shorting out. I did the decent thing (exchanged it!) before it could take out any of the expensive black boxes or even the battery. Bits of insulation came off some of the ignition wires, another chore requiring a bit of time and effort if not much money, just replace the dying wires.
The three cylinder engine showed its distaste for high revs with excessive vibration, though it was always thrumming away in the background even under moderate usage. The power doesn't actually run out until the vibes reach a level that blurs vision, so the real nutters can run them into the ground in a few thousand miles. I always backed off from that extreme, was rewarded with an engine that ran until 43000 miles...
It always was a noisy engine, lots of ringing, dinging and slapping, but added to that cacophony was a large amount of knocking and rattling - thrashed big-ends and main bearings. I didn't let the engine explode, an exchange crankshaft did the business. In fact, the bores were heavily worn by then but I decided to sell it rather than fix it. At quite a nice profit, too.
Loads of Kawasaki triples still about, the 500's costing serious dosh, with the 750 not far behind. The 250 and 400 triples are the relatively cheap ones, which is all the odder when you consider they are the toughest and easiest to use. They lack the sheer class of the bigger triples, not to mention the wild, wild handling antics and mad acceleration. It's all down to buying something that takes your fancy and taking the consequences.