Thursday 28 July 2022

Yamaha XS850

I purchased my new Yamaha XS850 back in November 1980, because I needed a bigger bike for touring than the Honda CB400T that I was quite happy to thrash back and forth to work, although I was getting damn tired of adjusting the chain all the time. A friend took me to the dealers on the back of his Guzzi SP1000, an experience I shall never forget. A change of underwear later saw me board my brand new bike.

The gearbox was, not surprisingly, tight with a resounding clunk with every change. First gear is still like that. At first the engine also felt tight but this soon disappeared once the oil began to circulate. Deciding to fill the 5.2 gallon tank up, I was prepared from straining myself putting the CB400T on its centre stand to put a lot of extra effort into the Yam, very nearly flipping the bike right over, much to the amusement of onlookers.

With a full tank of fuel I set about putting some miles on the clock. The handling was a bit twitchy on some of the uneven bends and had a tendency to white-line now and then. These problems were sorted out after experimenting with suspension settings and tyre pressures (36psi rear, 32psi front). The first 500 mile service was done within a fortnight and cost around a fiver - the oil was changed and one of the valves adjusted.


Winter saw the chrome covered in WD40 and the enamel waxed, which kept the rust at bay. Despite the lack of a garage there were no starting problems and the grip on bad surfaces was good enough to avoid falling off (and I still haven’t). I was rather impressed.

My first long trip was a tour of Scotland. Loaded with luggage, we sped up the infamous M6 at 80 to 90mph into a strong wind that helped reduce fuel consumption to just 36mpg. Scotland’s twisting roads created no difficulties for the 850, considering it was fully laden it handled very well indeed. My first problem occurred when checking the oil sight glass it showed no oil, but after I topped it up and checked it later there was too much oil. Oil level varies depending on how the. bike feels. I change the GTX oil every 1500 miles and the filter at every other change.

Wet weather braking I can only describe as above average Jap, the twin front discs and single rear created no blue- brick moments. Pad life was around 5000 miles front, 10000 miles rear. I tried EBCs but was much happier with Ferodo or Brembo pads, although the latter do squeal a lot. The bike came with Avon Roadrunners which worked well, lasting for 9000 rear and 14000 miles front.

Two weeks out of warranty the ignition pick up coil went haywire, causing one cylinder to cut out and scare the hell out of me. Luckily, the dealer wrangled it so that it was repaired under guarantee. Just before the second winter I fitted a handlebar fairing - it took almost a whole day but kept most of the weather off and even improved the fuel consumption from 45 to 5Smpg.


Servicing the bike is pretty straightforward. The most frequent job is to strip and clean the brake calipers, especially during the winter as they soon become clogged up. Just changing the pads often means a complete strip down as the pad screws are seized and chewed up most times. The bolts securing the calipers also seize up, as does the rear brake pedal pivot.

Valve clearances are adjusted by shim, but on a three cylinder two valver, despite being a trifle fiddly, it’s quite straightforward - use of the special servicing tool is recommended. I never had to check or balance the CV carbs, although I did drain the float bowls before and after each winter. Although camchain adjustment is simple, I needed to replace mine after 29650 miles. Shaft drive maintenance was merely a question of topping up the oil level occasionally and greasing the splines where it attached to the rear wheel, the latter a real pain to remove because the silencers made removal of the wheel spindle impossible.

The original silencers lasted two winters, replaced by a used set purchased through MCN classifieds for £30. When I tried to remove the downpipes, I found the Allen bolts that secured the flanges into the head had corroded and it was impossible for the Allen key to grip. There was no room to wield a hacksaw and the dealer suggested that engine removal was necessary. As the bolt heads were slightly splined I bashed on a socket and prayed that there would be sufficient grip - it worked. The second exhaust system was wrecked after 18 months and I fitted a 3 into 1 Motad that was. easy to attach, didn’t affect performance and aided rear wheel removal.

The ignition coil packed up again at 39300 miles - seems to be a problem on the 850 - I replaced this one myself at the cost of £60. The rear shocks were thrown away at 18000 miles and replaced with stock items as the relative rarity of the 850 meant they were the only ones available. The steering head bearings were shot at 40000 miles, a relatively simply job becoming a nightmare when I decided to replace the leaking fork seals at the same time - they just wouldn’t budge and I had to take them to the dealer.


At 45000 miles the regulator/rectifier was replaced by a new item (£45), this incurred my wrath because the whole of the back end of the bike had to be stripped off to replace it and when I finally reached the elusive component all its mounting bolts were corroded. Apart from these little niggles the rest of the electrical system gave no trouble at all. The self cancelling indicators were excellent, only on motorways when they were needed on for a long time did you have to operate the switch again. Even the headlamp was above average for the Japs, the main beam was quite outstanding.


During the seven years I had the bike I can only recall replacing two (indicator) bulbs and not due to any electrical faults - once when a wind blew the bike over and once when a car driver reversed into the it. The starter button fell out of the right hand switch block, was impossible to repair, so I shoved a screwdriver into the hole when I wanted to start it - OK until you stall the bike in traffic. Just to even things out, the horn button fell out of the other switchgear cluster - the combination of a small screw and lots of insulation tape produced the perfect bodge.


The bike is now on its third battery, the regulator wrecked the second one. Starting problems were few and far between until recently, and the battery coped well with very cold conditions during the winter months. The horns were merely adequate and were eventually replaced with air horns. The rubber carb inlet mountings began to perish and recently water was being sucked into the engine in the rain, causing the middle pot to cut out. Used stubs and filter box (it was starting to fall apart) were fitted. All that was at 45000 miles.


Despite being left out in the rain for most of its life, the finish is surprisingly good. Most of the chrome and paint is still there, only the tatty cast alloy wheels let down the appearance of the bike. I had to replace the rear mudguard but the front is still serviceable.

For the past three years the bike’s been limited to short journeys back and forth to work which I think has gone a long way to explaining its recent decline. It became a bit of a beast in traffic, rattling and not pulling away like it used to. A compression test revealed the middle pot way down. It started very badly on occasion - sometimes it refused to start even with the extra power of a car battery connected up. Pushing an XS850 is not fun. Then there were thumping and knocking noises from the bottom end.

I decided to strip the engine before it blew up. Two engine mounting bolts had seized up and sheared off. The motor was, er, very heavy. Once on the bench the head nuts didn’t want to undo and slipped when attacked with a socket wrench. I had to drill one off. The cylinder block was stuck fast and took hours to remove, and suffered several broken fins by the time I’d finished levering it off. The bores seemed OK but the valvegear was a mess and will probably have to be renewed. I’m taking my time restoring the engine to its former glory, hoping to have it back on the road by the time the next summer comes around. It’s just a pity they couldn’t use better components to hold together what is basically quite a tough engine, it would have made my life so much easier.


All in all, the XS850 is a good tourer, it loves long distance journeys and will travel all day at high speeds. It is OK around town but not for too long. It also likes twisting roads and country lanes but, if you buy one, bear in mind that it won’t take the boy racer treatment (it weighs 520lbs dry for a start). My XS has served me well over the past seven years and if the rebuild is successful I hope for a few more years life out of it. I suppose I’ve become rather attached to it and just refuse to let it lay down and die - basically I love it.


Dave Wilson