Classic Spannerman: Your motorbike maintenance problems solved!

Spannerman lends even more of his infinite workshop wisdom to the home bike mechanic. This time, he looks at some older gear…

He’s managed to fool the entire planet that he knows a bit. Who are we to interrupt the tradition?

OK, he actually does know a fair whack about bikes. Let’s check out some more of his incredible work…

Peter asked…

I’m considering the purchase of a 1983 Honda VF750. I’ve located one with 35,000 original kilometres on it, but the owner tells me it has an issue with the neutral light coming on when you change from first to second gear.

Do you think this could this be a major problem to fix? The owner says he’s looked at the neutral light switch and it seems to be doing its job except for flashing on at that first gear change.

I love these older bikes but I know they can take a fair bit of TLC to keep them in good shape. The asking price is only $2300, no doubt low because it can’t get a roadworthy with the neutral light problem. Any guidance would be greatly appreciated.

Spannerman responds…

By itself, Peter, the neutral light flashing as you pass from first to second isn’t a problem. Does the gearbox behave normally? Does it shift up and down when asked to and will it stay in the gear you want? Does it sound the same in each gear? If so, don’t sweat the green flash. It isn’t a roadworthy item, either, so don’t worry about that.

A clean, straight, original VF750 would still be a very nice ride. Early VF engines had a common problem with the hardening on the cam lobes becoming pitted and flakey. It didn’t stop the engines but had the potential to substantially reduce engine life. Honda partly addressed the problem by specifying a particular lubricating oil blend you could only buy from Honda dealers.

The VF was a class leader in production racing in the early ’80s and it wasn’t just because AJ and Wally were the factory riders. Mal (Wally) Campbell had occasional problems with the clutch on his bike as it didn’t like being slipped off the start line. Andrew Johnson (AJ) only had two fingers on his clutch hand and used the clutch as an on/off switch, which it preferred.

A good VF750 would certainly be worth considering at that price but you’d need to service it fastidiously and accept an engine rebuild now is money you probably wouldn’t get back if and when you decided to sell it.

John asked…

I’m wondering if you have any words of wisdom about getting the front fork tubes from a Kawasaki GPz750R rechromed. Some years ago I refurbished a Triumph Speed Twin. I had the fork leg tubes rechromed by a company that clearly didn’t understand what it was doing. The forks had been buffed to death before chroming and the end result was very good chrome on wavey, undersize front fork sections – the forks were completely ruined.

After 15 years, the front fork tubes on my ’87 GPz became pitted, ruining the seals. I looked at eight second-hand sets, all of which had worse pitting than the originals. I got a new set from the factory at eye-watering expense.

Now, the chrome on the fork tubes is just as pitted as the first set was. I’m not going to get another set from Japan. I’d like to get the current set refurbished but I don’t want a repeat of the Triumph incident. Got any suggestions?

Spannerman responds…

You haven’t named the business that dissatisfied you all those years ago, John, but fork rechroming isn’t rocket science and as long as the specs of the original tubes are known, machine grinding can perfectly reproduce them.

Are you in NZ? Try Murray DeLacy Racing Services in Hamilton (tel: (07) 847 8479). There are also good places in Australia including Rad Hard Chroming in Rocklea, Queensland (www.radhardchroming.com.au).

Mick asked…

At 14,000km, my mostly stock Yamaha XT500 (’81) has developed a slight weep at the head gasket on the left side. I really don’t want to pull it apart as my experience with car engines is that once you open them up the can of worms starts squirming and a quick head gasket replacement job ends up being a new camchain, guides, tensioners, valve grind, head grind etc.

A contact from the SR500 forum whose opinion I respect a great deal says if the weep is very slight, I might as well spend half an hour retensioning the head bolts to see if it fixes it. I guess I would characterise the weep as very slight since I only really noticed it after a ride on a dusty road left a bit of dust stuck to the weeping area.

I figure the odds are probably against the retension working but it’s such a quick job I figure it’s worth a try.

Anyway, just another couple of questions. My manual suggests a tension of around 29ftlb. Is that right, do you reckon? I’m used to pulling car heads down to 100ftlb or more. What happens if I give the XT a few more pounds?

I enjoyed the marital advice you gave that bloke recently (his missus only sticks with him because he’s fabulous in the sack). I recently rode my SR500 in the Craig Kerley Memorial Run.

It rained so hard I briefly considered buying one of those new-fangled full-face helmets. Anyway, the bike got a bit muddy and my wife’s response was positively unkind when I asked her to wash it for me. Was I out of order?

Spannerman responds…

Most XT500 owners can only dream of “a slight weep at the head gasket on the left side”. After a hot ride, most of them aren’t allowed into the public bar unless they take their boots off.

I have to say retensioning is unlikely to work but you don’t have much to lose. There are a variety of nuts and bolts on an XT head and head cover, and because the tension required varies in an attempt to provide an even clamping load, you need to refer to a factory workshop manual.

Only the 10mm nuts get the full 27.5ftlb torque – the 8mm ones should be torqued to 14.5ftlb and the 6mm bolts only to 7.0ftlb. They have to be tightened in a specific order, too, which will again require you to refer to the workshop manual.

When you know the order and the correct torque settings, here’s a tip: follow the tightening sequence but loosen the nuts off a fraction before pulling them back up to the required setting. They’ll make a ‘crack’ sound as you initially break the bond and if you follow this procedure, you’ll get a more accurate result.

What’s wrong with “giving it a few more foot-pounds”? The clamping load is determined by friction between the fasteners’ threads and the bolt or nut head against the cylinder head.

Head bolts are designed to stretch a little anyway as the engine heats up and cools down. If you over-tighten, the threads can be damaged as this takes place, potentially weakening the clamping load. Oh, and it’s a real bugger if you pull the thread out of the cylinder barrel.

Stick to the manufacturer’s recommendations. If it doesn’t work, Mick, and it really is just a slight misty weep, live with it. If it gets worse, write again and I’ll tell you how to maximise your chances of an even clamping load with a new head gasket.

Cathy asked…

I’m a 44-year-old lady and only 4ft 11in. I’m fairly new to riding and I’m currently on a Honda DN-01. Because it’s fully automatic, most blokes say it isn’t really a bike, but I’m comfortable on it and I really enjoy riding.

I’m beginning to think I’ve taken the easy way out, and now I have a few kilometres under my belt I would like to try a conventional bike. The DN-01 has a seat height of 690mm and weighs 269kg. I can’t really go over a 700mm seat height, but wouldn’t mind something lighter.

Spannerman responds…

Geeze, Cathy – 4ft 11in.

The problem you have is that a bike that meets the specifications you’ve outlined above is likely to be something like a 250cc cruiser (the Suzuki VL Intruder springs to mind – with a seat height of 685mm).

It will be lighter and they’re fairly easy to ride, but it will have less than half the performance of your DN-01.

The Honda is a genuine 160km/h bike with enough grunt to get you up the steepest hills without breaking into a sweat. A 250 cruiser will be flat out at 120km/h (and slow from about 80km/h onwards) and you need to row up and down the gearbox to maintain road speed in hilly terrain.

On top of that, if you’re comfortable with the DN-01’s upright riding position, you might find the seating position on a cruiser a little unnatural.

There is a Plan B. Triumph has versions of its Bonneville with 17in wheels, making it a lot closer to the ground. It’s also reshaped the seat to reduce seat height even further and set the ’bars back to make the riding experience comfortable for shorties. Seat height on this bike is 740mm.

You could get the seat height down to around 700mm with professional lowering (around $800). It would reduce ground and cornering clearance but they’d still be more than acceptable.

Oh, and your male mates would pull their heads in as well – respect!

Richard asked…

I recently acquired a 1994 Yamaha FZR600 for a small sum.

Once I had it on the road, I noticed the clutch was slipping fairly badly. It does this in any gear while accelerating down the road at full throttle. When the revs get to 6000, the tacho needle swings towards the redline with no corresponding increase in road speed.

I took the clutch plates and springs out and was dismayed to find they were perfectly within the manufacturer’s service limits.

When I bought it, I immediately did an oil change using Castrol GTX2. Internet weirdos assured me this oil would be a fine alternative to motorcycle oils and was supposedly the recommended engine oil for several old Kawasakis. Is the oil the problem?

Spannerman responds…

You got absolutely crap advice regarding GTX2, Richard. It has friction modifiers in it that will have bonded to the clutch plates and caused the slippage you’ve described.

It’s very hard to clean up as it’s a chemical bond rather than a coating. Give the plates a scrub using kero and then a light rub on fine-grade emery paper. Wash the plates thoroughly again afterwards. Change the engine oil (try Castrol Activ4T) and oil filter. Fingers crossed…

Don asked…

I’m 71 going on 30 and fang a ’99 BMW R 1100 S. After a recent knee replacement I find it a bit dicky getting my leg back on the left peg.

Are you aware of a peg lowering kit and also a high ’bar kit to suit the old girl? I can’t bring myself to sell the best bike I’ve ever owned.

Spannerman responds…

One of the joys of BMW ownership is an excellent parts and service network, even for very old models. Much of this is outside the official BMW umbrella.

BMW doesn’t mind too much, I suspect, as it encourages brand loyalty and lets the company get on with the big money tasks of new bike sales and service. Among the best are BM Motorcycles in Ringwood (tel: (03) 9870 3807).

BMW had an aftermarket ‘Bar High’ kit for the R 1100 S, but talk to the businesses above before you do anything rash with your credit card.

Razz asked…

Firstly, I’ve just bought a second-hand Remus Y-pipe and muffler for an ’04 BMW Rockster, and I would appreciate some fitting information. Will I have to use a sealant on the joints? Is it just a bolt-on job? Should I put a Power Commander on the bike, or will it be okay as it is?

Secondly, I recently bought a restored ’78 BMW R100RS from a friend for $5000. I feel as though I’ve robbed him but he needed the money and was happy it went to a good home.

It has an RT fairing on it at the moment, but I have all the original RS bits, which I’m going to have painted in the correct colours. I’ll be storing the bike for around 12 months and would like some tips on this process. A

ll the RT bodywork will be coming off soon so the old girl will be in the shed naked, waiting for her new clothes. Any help would be appreciated.

Spannerman responds…

The Remus Y-pipe and muffler will just bolt on, Razz, but a thin smear of a heat-resistant sealant won’t hurt.

The system is designed to work without having to alter the fuel mixture but Motohansa (tel: (02) 9638 4488) now sells a beaut little device called a “Protuner”, which plugs into your existing wiring and allows you to make mixture adjustments if required.

All is explained in the instructions, it’s really easy to fit and it costs $400.

Regarding the R100RS, it will survive 12 months without much storage work. Give it a good run to get it hot and replace all the fluids (engine, gearbox and final drive).

Oils are contaminated in use and the acids present can damage the metals which sit in them if the mixture isn’t stirred up regularly.

Take the plugs out and liberally squirt some engine oil into the bores. Turn the engine over a few times to spread the coating. Replace the plugs to finger-tightness. Put a plastic shopping bag over the end of each muffler and secure it with a rubber band to keep moisture out of the exhaust system.

Drain and clean the float bowls of the carbs. Reattach them but leave them empty (don’t turn the fuel taps to prime).

Remove the battery and give it a light charge on the garage bench every couple of weeks. Once a month or so, turn the engine over a couple of times, either with the kick start if your engine has one or by rotating the rear wheel, while the bike is in fifth gear.

This will be easier to do if you unscrew the plugs again. Leave the bike on its centrestand and rotate the front wheel every now and then to change the contact patch with the garage floor.

Can we have a picture of the RS when it’s finished, please?

Stu asked…

I ride a BMW F 650 GS Dakar (2003) and I’m becoming increasingly frustrated by the limited selection of rear tyres on offer for my machine. The standard rim is 3.00 x 17in. My local bike shop doesn’t even keep heavy duty 17in tubes anymore.

Can an 18in rim be laced to my original hub? If so, should I stick to the same width or also increase that? There seems to be plenty of room around the swingarm to accommodate the change.

What, if any, change could I expect in the bike’s handling? I imagine seat height and ground clearance would increase slightly. I think my speedo reads from the rear wheel as well.

How would the change affect the speed readings? Can this be done and is it worth the cost and effort?

Spannerman responds…

I’m sure other Dakar owners share your frustration, Stu, so I’ll be a bit surprised if others haven’t already tried this.

We’d both like to hear from them! It won’t be cheap as the angle of the spoke mounts on the hub is unusual, meaning more labour for the wheel builder.

Options you’d have would be 2.50, 3.00 or 3.50 and your decision should probably be based on what kind of riding you do most.

You’ll have the biggest choice of tyres with a 2.50 x 18in rim. Contrary to popular belief, wide rims and tyres don’t necessarily improve handling and the relationship between the front and rear wheel sizes is an important design feature in the stability of the bike.

While you won’t have any dramas with the width of the new tyre/rim combination, you need to ensure there is enough space between the top of the tyre and the rear guard when the rear suspension is fully compressed.

The total job could end up costing around $800 and, again, whether it’s worth it will be based mostly on what kind of riding you do. I’d be tempted to stock up on 17in tubes and focus my mind on the Dakar’s many virtues rather than its few faults.

Wanna ask Spannerman a question? Of course you do. Email us with ‘Spanner Question’ in the subject line at: admin@infomoto.com.au