Monday 23 January 2012

MZ Tales

I like MZ's. Actually, I'm a bit of a fanatic when it comes to them. Not only am I general secretary of the 850-member MZ Riders Club but I also race them as a member of a team from those well known purveyors of MZ's - Burwin Motorcycles of London. I must confess that I have five MZ's in addition to a VFR750. I'll endeavour to give a reasonably unbiased account of my ten years aboard these, er, highly individualist machines.

MZ's are like Ducatis, Brit iron or anything else that's outside of the mainstream. You either cherish them or absolutely hate them, there's little middle ground. Most who buy one usually do so for reasons of cost, very often not through choice, but before long become incredibly loyal. I am one such sad individual.

The first MZ was a 1979 TS150 with 3000 miles on the clock. It was summer 1985 and I had no wheels whilst awaiting arrival of my new 550 four. A friend said that he'd come into possession of something that might interest me. As he opened his garage door I stood aghast. ''You jest,'' said I. However, never having been so close to a Zed before, I was interested. Like so many others, I ridiculed them without actually knowing what I was talking about.

I soon became fascinated and grudgingly had to acknowledge the high quality paint and the solidly built aura that surrounded it. My friend explained how a neighbour had bought it to pass his test upon several years previously, thereafter he abandoned it under a tarpaulin, forsaking it for more glamorous tackle.

My mate simply replaced the battery, put new rings in (the piston had seized due to corrosion during its period of idleness) and cleaned it up. For a six year old bike it looked new. Anyway, to cut a long story short he persuaded me to have a go. I was quietly and pleasantly surprised. A deal was struck for £50.

I sold it 30,000 miles, one set of rings, several tyres and sets of points, five years and many smiles later for £50. The best value biking I've ever had. That bike let me commute between Lincoln and York University twice a week for a year without any real drama except for a few problems. Sure, it certainly wasn't without its fault but I loved it.

The TS was slow at 70mph max, never showed any sign of acceleration whatsoever (the widely spaced gear ratios combined with the relatively narrow power-band), it wasn't exactly a head turner (but I thought it looked like a motorcycle) and it didn't carry much cred in the local boozer. However, it would always get me wherever I wanted, it would cruise endlessly at 55mph and turn in 90 to 100mpg, carry luggage and a passenger with no ill-effects. It handled excellently due to well damped and sensibly sprung suspension.

The downside was brakes that were feeble but when shown a hint of rain would become extraordinarily unpredictable. Sometimes putting my feet down would have been more efficient and on other occasions they would viciously lock the wheels solid as though someone had put a jemmy through the spokes. Frightening! Then there was the Pneumat tyres, made from teflon and ever lasting, ready to add some spice to the cocktail.

The TS ran on pre-mix and preferred it on the rich side (30:1) which didn't seem to affect plug life adversely. They lasted 5-6000 miles. Some people hate pre-mix but I'm a traditionalist and for me it adds to the experience.

The six volt electrical system was very good compared to those available on similarly modest Jap commuters but, nevertheless, was still dangerously inadequate for unlit country roads. Being powered by a dynamo it would never be strong enough - that's why most generators are three phase types, these days, it's the only way to obtain sufficient power from the small generators fitted to motorcycles.

It was possible to convert to 12V but this needed the rider to keep at least 3500rpm on the clock to work. Being an electronics engineer I know about these things. The switches were old-fashioned (by MZ standards) and tended to wear holes in one's gloves.

The clutch was extremely heavy which despite regular adjustment, change of cable and plentiful lubrication never got any better. Others are just the same and you learn to live with it, at least it builds up your wrist muscles but does make delicate control in town traffic tiring.

The TS wasn't a bike that tolerated thrashing, whilst such abuse seemed to have little detrimental effect, it never resulted in shorter journey times, only intrusive vibration once 60mph was reached. It was far more advisable to settle for less mental stress and 50-55mph, a speed it'd hold indefinitely whatever the gradient, weather or load. Due to the slow revving but torque filled nature of the engine coupled with tallish gearing. As far as I could ascertain from the wild dance of the speedo and tacho, 55mph equated to about 4500rpm. At such speeds the bike felt like it would continue for years, so solid was its build.

I lent the bike to my younger brother, his Honda trail bike having submitted to his merciless right hand. This was a bad move. One day, on my newly acquired ETZ250, I came up behind what appeared to be a very fast TS. At an indicated eighty I was only just gaining on it. Imagine my astonishment to clock it at that speed. Even greater was my surprise when I realised it was mine. Back home, I was verging on melt-down - no way to treat a bike like the TS.

A few weeks later it seized. The piston, rod and mains were all shagged by excessive revving and lack of oil. A total rebuild cost only £70 but, thereafter, it was never quite the same again. I could never quite put my finger on it; gone was its lovely smooth, sweet running at its usual cruising speed, wouldn't return the same fuel consumption as previously. I didn't talk to my bruv for many weeks.

One fault that took some time to sort was carb icing in winter. Not being particularly experienced at the time, I was driven mad for weeks by it running rich and its refusal to take three-quarters throttle. Whilst fumbling with the carb in bits by the side of the A1 deep in snow and slush with a rapidly dying battery providing illumination, I finally discovered the cause - a lump of ice in the float bowl. Water ran down the throttle cable and worked its way into the float bowl. The water/ice mix created havoc. Once I'd sealed the cable with a heat shrink sleeve, the fault never appeared again but for a few miserable weeks it made life hell.

So it was less than perfect and broke down on a few occasions but I never ceased to enjoy riding it (isn't that what it's all about) and despite the jibes from my mates they eventually had to admit that it was a good bike, too. They can withstand criminal neglect but were often ruined by owners who couldn't care less, are now becoming somewhat rare...The best ones are found among members of the MZRC, who tend to look after them. A runner can be had for £50 and a really good one for £250-300. It's worth paying more and if you look after it you'll be rewarded with a reliable bike.

Whilst singing the praises of the TS150 I still hankered for something with a bit more go. I found an immaculate one year and 3000 mile old ETZ 250 for £540, including a tri-point screen and rack in a local Kawasaki dealer. Despite much effort he wouldn't haggle and I paid the asking price. It seemed expensive at the time but after 20,000 miles I sold it for £480, so I guess that I had little to complain about really.

ETZ's have always been in demand, universally recognised as being made from the right stuff. This bike didn't impress me initially. It wasn't much quicker in absolute terms (75-80mph), drank fuel quicker than an alcoholic drank Bourbon and felt gutless. It would struggle to hold 60mph on anything other than flat roads and always felt well overgeared. Changing the gearbox sprocket from the standard 20 tooth item to an 18 improved matters beyond expectation. Suddenly, the acceleration had some zap, fuel consumption improved from the low fifties into the mid sixties and the maximum speed was raised to over 80mph. The engine felt much happier because it was able to run at a more natural pace.

It's hard to believe but many MZ's came from the factory massively overgeared like that. They must've been using up excess stocks. The change certainly improved my opinion and riding became much more enjoyable. This bike was reliable during the 18 months of my ownership. It broke down once when a main fuse blew. Chains, despite being shrouded in the excellent enclosure, didn't last as long as I hoped - about 10,000 miles whether or not they were heavy duty. OE chains are often lucky to see 1000 miles before they start shedding rollers! Partly due to the long travel suspension and long chain run. It's made worse by the need to run the chain slacker than on Jap bikes as tight chains can kill the gearbox output shaft bearing.

Brake pads lasted about 10,000 miles. I preferred to use AP items, which gave ferocious and consistent performance whatever the conditions. As with all my bikes, I fitted Goodridge braided hose which enhanced performance even more. The caliper rarely required attention, unlike most Jap's the pistons have proper external seals to prevent the ingress of dirt. Rear shoe life was in excess of twenty thou. I used many varieties of tyres, all being pretty much the same with the exception of Metz ME77's - they gripped very well but didn't last for more than 4500 miles on the rear. That's on a par with my 750! Normally, rear's lasted about 10,000 and front's 15000 miles. The MZ really is a cheap bike to run.

One thing that really did piss me off was the poor quality points, original or pattern items never lasted long. They soon went out of adjustment (easily noticed by difficult starting and peaky, revvy behaviour) despite attention with a dial gauge. I also found that the points had too much slop in the them, leading to rather variable timing.

Fitting Burwins' electronic ignition (£45) solved the problem completely. This is an optically triggered system that did away with the points altogether and was very much fit and forget. Together with a copper core HT lead and a high output coil, also from Burwins, low speed running was smoother and fuel consumption improved. Eliminating the weekly chore of ignition timing made matters much easier. In fact, so little attention was required that one could consider the bike almost maintenance free. Spark plugs last for up to 8000 miles when used in conjunction with electronic ignition. Use a B8HS plug rather than the recommended B7HS, which is only for winter town riding. The former provided cooler running and more reliable starting.

The ETZ handles surprisingly well, especially on the ME77's and many a time I was able to see off more exotic machinery with ease. It's really quite sad and amusing to see your opponent try his utmost to get past, which he does eventually in a frenzy of revs. Reasonably well damped if soft suspension and conservative geometry makes for stable handling which combined with light weight allows one to get away with some pretty stupid antics.

I did some quite long trips on the bike, perfectly able to cover 200 to 400 miles in a day. The ride was quite smooth due to the ample suspension travel, the engine was rubber mounted, smoothed out at its natural cruising speed of 60 to 65mph (4-5000rpm). However, if I was in a hurry the 250 was perfectly happy to hold 70 to 75mph almost indefinitely; close to its top speed. Even then, the low state of tune meant the bike still felt relaxed.

Following cagers might not agree, as it's possible to generate quite a smog. I found with all my ETZ's that proper adjustment of the oil pump wasn't possible because the oil pump cable was too short - a generic fault and it usually takes some 10,000 miles before the cable has stretched enough to allow sufficient slack for proper adjustment. Not a serious fault as it just provides an excess of oil.

The plastic piping supplying oil from the tank to the pump is worth inspecting regularly. It can become kinked, tends to harden and crack. Use see-through pipes to see if air bubbles form, a sure sign of possible pump failure. After suffering two failures of the Mikuni oil pump (it's Japanese), I reverted to premix. I never ran at the recommended 50:1, the engine felt much happier with 40:1 or 33:1 when cruising at high speed.

Neither did I use expensive synthetic 2T oils, some of which seemed to really upset the engine. Instead, I used Witham's Easimix at £29 for 25 litres. The engine smokes quite a bit in town but soon clears at speed. Of all the oils this worked by far the best. After 20k on this stuff I had a look at the top end. Nothing amiss was found and there was little carbon build-up. I traded this bike for a brand new ETZ300.

I couldn't believe how much better was the 300. Felt completely different despite being identical except for the obvious. It was much more relaxed, little faster but far more punchy for those extra 50cc. At 60mph it was revving at a leisurely 3700rpm and at eighty it was turning at 5000 revs. Roll-on acceleration in top gear was much better, the 300 easily romping away; climbing hills there was no need to change down a gear. There was so much extra urge at low rpm that the gearing could be upped to 20 teeth at the gearbox.

Fuel consumption on my particular example was never less than good. It would consistently return 75 to 85mpg at 60 to 65mph when on long Continental jaunts, although thrashing reduced it to 50mpg. This was a figure that few friends in the MZRC would believe until I demonstrated it to them. I modified the ignition as with the 250.

My particular example was a converted 250, being done by Wilf Green, who was the importer at the time. He achieved the conversion by boring out the barrel to 75mm, modifying the head to retain a sensible compression ratio and fitting a Mahle piston (which later became very expensive at £120 due to the popularity of the conversion). The factory later cottoned on to this simple mod and marketed their own 300 housed in the ETZ 251 chassis.

I was and still am quite proud of my particular specimen. It was the first black 300 in the country. At that time, it was only available in a horrible orange which I refused to buy, so the dealer that I was quite friendly with got a black one for me specially. I thought it looked rather handsome! 300's prefer to run with slightly retarded ignition (2.5-2.6mm BTDC) compared to the 250 (2.5-3.00mm BTDC), this compensates for the slightly higher compression ratio.

Technically, I wrote this bike off in 1989 after 22000 miles and one year. On my way to a rally in Germany, I was very lucky to survive a head-on collision with a jeep when I lost the front end in heavy rain negotiating a steep gradient. The bike was a mess with forks bent at a crazy angle, snapped front wheel, headstock pushed back and much more besides. To add insult to injury, the German driver of the jeep lit a fag whilst trying to help me from under the bike - I was soaked in petrol at the time.

This did little for my disposition towards the nation! One thing's for sure, had I not been wearing a good helmet, boots and leathers I would probably have got hurt badly. As it was, I didn't have a bruise. The bike wasn't going anywhere but a generous garage proprietor stored it for me (until I returned later to collect it) and my brother, who was travelling with me (on his ETZ250), loaded as much luggage as possible and carried the pair of us the rest of the way.

His poor 250 was ridiculously overloaded, thrashed to within an inch of its life and performed admirably under the strain. We reached the rally and had a wild time. Evidently, news of my misfortune had travelled quickly; we were greeted with a cheer and a large round of beers. A local MZ dealer took pity on me, sold me a complete front end for £60 which, after the rally, was transported back to the crash site by some German MZ sidecar riding friends (I suppose combo's do have their uses after all). Within a couple of hours I was back on the road but with a wheelbase some six inches shorter than usual. Every time I used the front brake the wheel hit the engine. Nevertheless, I got home to Lincoln in the end.

During the following winter I completely rebuilt the bike, virtually everything powder coated (having private access to a sand-blaster helped) and rewired the electrical system. Five years on it still looks better than new, testimony to the quality of the powder coating and the fact that I no longer use the bike very much due to MZ racing commitments.

This bike had a load off mod's done to it, particularly on the electrical side because I'm an electronics engineer. Contrary to popular opinion expressed in the hallowed pages of the UMG and elsewhere, the regulators are not a weak point it's the regulator. An electro-mechanical type prone to going out of adjustment depressingly regularly. The manual describes how to set it up but in my experience this is rarely successful. A failing regulator usually manifests itself in overcharged batteries that have boiled dry, blown light bulbs and coils (all expensive).

Undercharging is also very obvious, the battery doesn't have much capacity and soon runs flat, ignition hiccups making their presence known before then. If the regulator fails it can be a sign of overcharging. MZ spares are normally cheap but regulators are an exception at £90. This is often more than the bike's worth but don't despair because an electronic equivalent can be bought from most auto-electrical shops for £5 to £15. Something equivalent to a Bosch three terminal 0192-062-001 will suffice. Much better, brighter lights and more consistent electrical performance.

The indicator relay's a bit duff as well, again a full electronic item from the wholesaler will do. Don't buy those cheap and nasty items from Halfords - they're so inefficient that they cause the headlight to flicker during operation and they aren't particularly reliable, either. If you're going to fit high power halogen lamps then I'd advise checking the wiring and connectors. The wire used by the factory is not of the best quality and is quickly shown up by the high currents flowing. In fact, the wiring can be so nasty after a few years that you really should rewire using quality stuff with an ample current rating.

The instruments on MZ's have always been of a dubious character, before long the needles are dancing wildly across the scale. I've always found this intensely annoying but, again, there is a cure - this time in the shape of a speedo from a post '85 rear engined Skoda. It fits straight in with no need to mess around with other cables. Apart from better reliability it also has a trip meter and reads to 110mph (in km, ideal for Continental trips). Some warning lights are lost but this wasn't a problem - I gutted the tacho, made a new face plate and fitted light emitting diodes as warning lights...a tacho's a bit superfluous on a bike which has a safe rev limit at 8500rpm but due to porting and exhaust will not get much past 6000.

One common mod's to lace a TS125/150 rear wheel on to the front of the ETZ. The standard rim's pathetically narrow, more suited to a 100. The TS rim takes a 3'' wide tyre that substantially improves wet and dry roadholding and braking. Hagons in London are well versed in this art. A wider front tyre on a stock rim actually ruins the steering and handling.

The front forks of the Zed are a bit limp, being both underdamped and undersprung. The underdamping is due to the damper rods having ridiculously large damping holes and valves. If you know what you're doing, you can weld them up and redrill but it's much easier to change the oil for 30 grade. Set the level to 135mm from the top of a compressed fork - needless to say, do this with the fork removed from the bike and no spring in it. 30 grade's very thick, the forks need to be pumped up and down and left to settle for 30 minutes. Use heavy duty springs intended for sidecar duty with new seals and damping rod piston rings. An amazing improvement in fork actions occurs when the fork legs are ever so slightly roughened with 400 grit emery cloth, the slight amount of lubrication from the oil makes the seals work better.

Sebac rear shocks work better than Hagons. Stock shocks are variable but don't last well as moisture gets inside them...some 300 shocks were fitted with 125 springs and the quality of the steel in the springs was variable, although recent ones are okay. Phosphor bronze swinging arm bearings are much better than the rubber/steel stockers.

MZ's are incredibly tough and can withstand an amazing amount of abuse, but, better still, look after them properly and they'll reward you with sterling service. For some people this means washing them once a month but I'm sure most of you know what I mean. There are several MZ's in the MZRC that have exceeded 100,000 miles with little more than new rings and mains. My brother's 300 hit 168,000 miles before the chassis expired, the motor now being in use in another chassis.
Some of the best biking I've ever had has been provided by these modest machines and that's the best thing about them. Without being mortgaged to the hilt with huge repayments and astronomical running costs you can have great fun on a Zed. Buy one and spend the rest of your savings on touring abroad. It's better than having a superbike you can't afford to keep in tyres stuck in the garage.

Nigel Wright