YAMAHA FZS600 FAZER Alan Dowds strips the bike down. A bit…
Al has picked up a neglected Fazer to pass the time while his turbo ZRX is at the exhaust welders. He’s made a mixed bag of discoveries this month. Would you like the good news or the bad news first?
So, on with my rather neglected 43k mile T-reg Fazer 600: I’m going to start with the good… As we covered last month, the first issues to look at are the rattly cam-chain and the leaky carbs, so I charge down to Wokingham with a car boot full of tools and cameras. Big CC obviously has a wall of Snap-on tool chests, but as we know, there’s nothing like your own tools, even if they’re a bit ‘pro-am’. Besides, whenever I work down there, I spend more time looking for tools in unfamiliar chests than I do using them.
The Fazer fundamentals come flooding back (I’ve had a couple of these in years gone by) and I have the seat and sidepanels off in minutes, followed by the tank. There’s a minor panic when I get to the fuel tap – when I turn it ‘off’, it starts leaking from the tap body. I quickly unplug the fuel sensor wiring, breather pipes and fuel line, then whip the tank up and off
and outside, sitting it at an angle so the fuel stops dripping. The Fazer fuel arrangements are a bit weird as it happens. It’s carburetted, obviously, but has an external electric fuel pump, presumably to improve on the gravity feed. The tap is not accessible until you lift the tank, so it’s not something you can turn off on a regular basis. If it’s only moved a few times in the past 20 years, I’m guessing that might be part of the reason for its leaking when I do finally turn it off.
Anyway, with the tank off, I can get access to two areas of interest – the carbs (obviously) and the cam-chain tensioner, which lives under the carb inlets, right in the centre of the block. Once, advance in modern engines meant to moving the cam-chain to the end of the crankshaft; that saves a main bearing compared to having it in the middle, so makes for a narrower engine with less friction, both good things. However, here it’s in the middle, making replacement (should I need it) and access a bit trickier than an end chain. The carbs come off easily enough: three bolts loosen the rear air-box section, and one slotted mount lets you tighten the bolt again to hold it back once the carbs are free. There’s a mounting plate above the carbs which holds the coils, filter and fuel pump, and it makes access much easier if you disconnect all that shizzle and unbolt the plate, setting it to one side. Watch for fuel leaking out of the pump and filter connectors.
Next, we loosen off the inlet stub and air-box rubber clamps, then slide the air-box back and off the carbs, and tighten that slotted top bolt mount to keep it out of the way. A large pry-bar or similar helps ease the carbs out of the head stubs, and we can lift them out, disconnecting the throttle cables when you get clear access.
Pro tip: you can pop some milk bottle tops into the inlet stubs to keep any rubbish out – they’re a perfect fit... I’m taking the carbs home today, to strip them properly in my own garage, so I give them a quick external clean down in the Big CC parts washer, then we’re quickly onto the cam-chain tensioner. Opinions differ wildly on these – some folk swear by a cam-chain change straight away, others prescribe weird, dangerous-sounding tactics to fix any rattles, revving the engine off the limiter in neutral, pushing screwdrivers in the tensioner hole and the like. Hmmm.
I’m hoping for a more conservative middle way though. The tensioner is, essentially a sprung, one-way ratchet mechanism, which should automatically push a plastic tensioning blade out against the slack side of the chain run as the engine is running. As the chain wears and stretches, the springs in the tensioner push it out another notch, and the locking ratchet pawl stops it moving back again. If the spring gets weak, or the ratchet mechanism sticks, the chain free play won’t be taken up, and it flaps about inside the cam-chain tunnel, making the light rattling sound I heard.
It’s easy enough to whip the tensioner out for a look – just take care that the engine can’t move or turn over, by disconnecting the battery if you haven’t already (it’s good practice to do that before any work really) and making sure the gearbox is in neutral. Then, unbolt the big 12mm hex-headed plug in the centre. Remove carefully – there are two springs and two ball bearings inside here – and put to one side for a look.
Then, unscrew the two 5mm Allen bolts and remove the main tensioner body. Doing it this way lets you see how much travel the tensioner has taken up – if you take the tensioner out in one part, the spring will push the ratchet arm all the way out, and you can’t see how much it was adjusted out. We decide this is good news. The tensioner is only just halfway-out, with loads of travel remaining to be used. And close inspection reveals that the ratchet teeth were a bit discoloured on the last click, as if light corrosion or dirt had stuck it in place. The springs and ball bearings were also a bit gungy – so we reckon a good clean up, with fresh oil and a bit of a run should get the tensioner clicking out again, and taking up the free play. It’s certainly good enough for the moment – but once we get the engine running again, if there’s still a rattle, we’ll look at a new cam-chain and tensioner then. While I have the tank off, I have a quick look at the air-filter. It’s hidden under a rubber cover, then secured with four screws. Once I get it out, I have a bit of a chuckle – the filter is brand new, with the date of fitting and mileage written on it, in Lynn from Big CC’S handwriting.
As with the battery, the date written on there is October 2007, and the mileage 42,000 – confirming that this bike has only done just over a thousand miles in the past 12 years. Now, Lynn is a proper pro, so he would definitely have done the engine oil and filter at the same time – so at least we know the Fazer had a decent service before being parked up. If only the fuel tank had been drained too…
I pack up at Big CC, putting the Fazer back into the storage lock-up, and head home with the fuel tank, coil/filter bracket plate, and carbs in the back of my Audi estate, stinking it out with crappy petrol. The tank feels about three-quarters full of gas, but I need to sort the weeping tap out, as well as stripping the carbs, replacing the fuel filter and I’ll also give the coils a bit of a once-over too. In my garage, I set the carbs to one side, and start with the tank, if only to stop the stench of old petrol. First problem is getting the tap off – it’s held in by two big cross-headed screws, and they are effing tight.
It feels like they have a load of rust in the end threads, because they loosen easily enough, then get tighter as they come out through the tap and tank body. One comes out okay, but the other starts to chew up. I’m using my best-fitting screwdriver, which normally does the business with those JIS screws, but on the final few turns, the head collapses, and I have to get the Teng Vicegrips out. Bugger – but job done. I hold the tank over a fuel jug, and the worst fuel I’ve ever seen in my life floods out. It’s brown, like a cup of builders’ tea made by Satan himself, and it smells like utter death. Twelve litres of vintage unleaded, presumably more than a decade old, is decanted into a jerry can, to await further inspection.
I put some into a clear glass bottle for a proper look at it – manky indeed. Pouring some through a coffee filter reveals that it’s all just very fine brown rust particles. Nice. Ten minutes has the fuel tap apart – and indeed, there’s a worn section in the main rubber seal. The twin upper inlet ports look like eyes, and the lower outlet slot is like a wailing mouth, the little tap bemoaning its woeful condition – but she’ll be right in no time, with a repair kit ordered off the Bay for less than a tenner posted…
Next month is the carbs – and as it turns out, I reckon old Tappy the fuel tap had seen what was inside them, which explains his Munch-style Scream visage…cmm