Since my words of wisdom on my Z650 (UMG 21) were written around 40000 miles have passed under the wheels. I think what I have learned about the running costs and reliability of the bike will be quite useful to anyone thinking about buying one of these ageing UJMs. Certainly of more use than a featured bike in another magazine, which had done all of 12000 miles in 12 years.
First, the good news. The bike now has 80000 miles up and the shims have not been touched since I bought it with 32000 miles. A far cry from my old CB750F1 which seemed to need the tappets done every 2000 miles or so. Also, unlike my seventies Hondas, the camchain has required minimal attention. I skin my knuckles on the awkwardly placed tensioner every 5000 or so miles, more for peace of mind than because it needs doing. The sole exception to this was when the camchain decided to loosen itself during a despatch job in Wales. Mucho paranoia was caused by the horrendous noise but a swift roadside re-tension cured it.
As the bike is my only transport and was also used as the means of making a living, the engine’s durability has been welcome. I put it down to solid seventies Kawasaki engineering and frequent oil/filter changes -- every 1000/2000 miles using 10/40 oil. Like its larger brothers, it’s advisable to keep an eye on the level, a process made easy, if a trifle hard on the knees, by a sight glass in the crankcase. The bad news is the Z is now dormant in the garage, as just about everything else has worn out or fallen off and I can’t afford to replace them.
The biggest shock on the running cost front has been the rear tyres. l have always used Metzelers as the bike came with them and they have been so good, wet or dry, I have never bothered to change brands. The rear ME99 comes with a built in wear indicator, at about 2mm it follows white lines in a most disconcerting manner- The tyre lasts for only 5000 miles or 4000 miles if you up the pressure to that recommended for high speed riding, although solo there’s not much difference in handling. At least the front ME33 lasts for 12000 miles although there’s only 4mm of tread on a new tyre. l was put out by the tyre wear as one of the main reasons for buying the Z650 instead of the Z1000 was supposed to be lower running costs. I am not impressed!
While on tyres, I've had more punctures on this bike than on all my other bikes put together, despite paranoid daily tyre inspections. OK, I do a high mileage, but the Z seems to have a magnetic attraction for any stray hedge trimmings, nails or glass. A glance at the last year’s receipts shows l have purchased eight inner tubes, two puncture repair kits and four instant repair aerosols. l have never attained good results from the latter, the furthest l have gone with one of these repairs is 10 miles, the shortest 10 yards. Maybe the combination of 11 stone of rider and 500lbs of Kawasaki is too much...
My Z650 is an early model with a rear drum, which has only needed stripping and cleaning once in 50000 miles, a ten minute job done whilst changing tyres. The shoes are only just ready for replacement. lmpressive! As for the front disc... there will now be a short break while your scribe tears his beard out by the roots and bangs his head against the nearest convenient wall. The pads last well - longer than the calipers, anyway.
After a few thousand miles, the sponginess of the front brake began to annoy me. Despite an overnight soaking with WD40, the bleed nipple sheared off under the lightest of pressure. One set of knackered extractors later, I let the local blacksmith have a go. He cracked the body of the caliper and broke the bridge pipe leading from the hose to the caliper into the bargain. I went to the local breakers and scored a bagful of ruined calipers, in an attempt to make one good ’un. No chance. At least I got enough bits to keep me going in pads and pistons...
A visit to another breaker secured a decent caliper. Mr Kawasaki wanted a very silly amount for the bridge pipe but I got one made up at a local garage for the sum of £1.38. The obscure connections at either end of the pipe were bought from GKN Autoparts for 38p, and a local garage made up the pipe for £1. For the first time I felt I was winning... when I felt the brakes were getting a little spongy again, a close examination of the caliper revealed a hairline crack in the body. As I have not hit this part of the bike with a large hammer (oh, how I’ve been tempted!) I can only guess at old age being the cause.
The pads themselves last for anywhere between 10 and 15000 miles. Even when the Z650 was launched, the press only described the braking as average. It is a reasonably simple matter to uprate to twin discs using parts from a breaker. Assuming I have not bought all the used calipers in the UK, that is. If you do this, it is very advisable to uprate the master cylinder to a later twin disc model. Stainless steel hose is also recommended.
Next in the list of items that ought not to wear out but do, we come to the speedo drive. The original failed at 53000 miles. A visit to the breakers and five quid poorer, resulted in a replacement. 583 miles later that one gave up the ghost. A replacement was obtained free of charge, but was for a different size spindle. As speedo cables only last a few thou, l have given up until the next MOT and rely on the tacho -— well until that cable went as well.
Next, we come to the chain and sprockets. With regular lubing and tensioning, a heavy duty chain, circa £18 mail order, lasts a credible 10000 miles; sprockets about twice that. Pushing it beyond that, as l foolishly recently tried to do, can result in a snapped chain and teeth that look like they have had an argument with the old SPG. Luckily, only surface damage to the crankcase was caused. Make sure it’s a HD chain, I tried a normal one which broke at the split link twice and shed half its rollers all in a week!
Also at the back end, the chainguard committed suicide by leaping into the rear wheel. A Z1000 item was hacked about until it fitted. Marzocchi shocks do the business at the back end and have only just been jacked up to the middle setting. They do not look good, finished in oil and chipped paint, but they work. Also without drama has been the Yoshi box section swinging arm... I dread to think what the standard Kawasaki stuff would be like after 80000 miles.
As for the front suspension, the Roadrider air caps that the previous owner fitted keep their pressure well - I run them at about 12-15psi. As the forks do their job I have not changed the oil yet, although as part of its rebuild I will. The front mudguard, which helps brace the forks, is still reasonably solid if a little rusty. Like the GS550/750s it's advisable to fit a fork brace if you replace the guard with a plastic item.
My Z650 came with a steering damper. I did not realise how much difference this made until it worked loose one day and the bike started doing all manner of strange things in my favourite series of S bends. A very useful item. Even in standard form the Z's not too bad a handler but the damper keeps the occasional twitch under control.
The hacked off Piper 4—1 blew its end cap off about 6000 miles after I bought the bike. Due to a lack of secondhand exhausts I kept going for several months by living on cans of tuna - they were just the right size to be jammed up into the body of the silencer. Eventually, I got sick of tuna and sent off for a new Motad. Of course, the day after I had fitted it someone phoned up to offer me a set of brand new, original pipes for £80...
Fitting the Motad was quite fun. For once, l followed the instructions - four hours later I still had not got a gasket tight seal. I removed the lot and set to with the universal spanner (a hammer) and a block of wood to protect the chrome and my fingers. After ten minutes, no problems left.
With the new exhaust the overall performance was much improved. The Z had trouble pulling much over the magic ton before, except on open pipes (and somewhere in Wales there is a seriously upset Z1300 owner who was probably deafened as well as embarrassed by a bike half his size pissing past him in the twisties).
With the Motad, it would pull an easy 115mph and on one occasion 120mph! I must admit the Z is not too pleasant to ride above 105mph, although it still runs true, the clocks shake like a belly dancer on speed and with the standard riding position you feel as if you are going to be blown off the back. I thought the whole bike was going to fall apart. Reminded me of the first time I went over 100mph on a 650 Bonnie.
With the Motad, the tickover was steadier and the whole engine sounded much happier. l was also impressed by the solid construction of the 4-1. One day, the silencer fell off and went under an artic’s wheel. When recovered later, the only damage was slightly scratched chrome!
Talking of damage, during a crazy fortnight the bike was driven into 3 times whilst parked. The total damage was a broken headlamp, tail light, number plate, one clutch lever and two brake levers. Oh, and damaged pride - on one occasion I was sitting on the bike! Each time I managed to catch the culprit and extract compensation.
The levers were replaced with dogleg types, purchased mail order for £7. A vast improvement on the standard type and only a quarter of the price. I could not get a replacement Cibie for love nor money, so settled for a Z750 OH headlamp from the breakers for £12 -- new it would have been £60. Nice main beam, but the dip could not hold a candle to the Cibies. By now, the breaker was convinced I was either parked in the central lane of a motorway or falling off a lot and lying.
After the original rectifier went up in an expensive cloud of smoke I made my own - l was a little careless with crimping one of the connections, with the result of an exploding battery. Quite a weird feeling when you are riding the bike! After months of minor electrical hassles, I spent a long weekend replacing dodgy connectors, plug caps and so on. As soon as I did that the electric boot gave up, as did the kickstart lever.
l have recently replaced the air filter, which was well overdue. In their wisdom Kawasaki placed this directly under the join between tank and seat, so if the bike is parked in the rain or washed, water soaks into the filter. There is a minute drain hole. which blocks up easily. My reputation for eccentricity has not been improved by pegging the air filter on the washing line or attacking it with a hairdryer.
After 80000 miles both head and base gaskets leak oil. I usually let it build up for a few weeks, then remove it with engine cleaner. You may have recently noticed Kawasaki adverts saying that all their bikes since the seventies can run on unleaded. They can, but not very well if my experience is anything to go by. Top end down by 5mph, consumption down from 42 to 36mpg, pinking, rough tickover... it was back to four star pronto.
Would I have another one? You bet. Any 12 year old bike that will stand being thrashed each and every weekday for 18 months and required a minimum of care except for oil changes is OK by me. I have given up the terrors of the despatch game now, so the Z and myself can have a rest. With the GS550, the Z650 must rank as one of the best of the old fashioned UJMs
Bruce Enzer