Advice: Technical Q & A

SOAPBOX
While you probably think testing motorcycles is as close as you can get to the perfect job, it's often a nuisance to pick them up and drop them off afterwards. Occasionally it's made easier if the distributor lets you leave one of your own bikes there during the test period so you can ride to the distributor's site and ride home afterwards.

This was the case with the BMW S 1000 RR test in this issue and I left a 1980 Suzuki GS1000G. BM's factory workshop is like an operating theatre and the GS stood out like a pork chop in a synagogue. Most of the staff there were at least polite but technical boss Steve Adcock, who's been providing me test bikes for 32 years, abandoned civility after the first six months.

He complained about how heavy the GS was to push around compared to the S 1000 RR and, when I returned to collect it, I had to spend 20 minutes trying to find where he'd hidden it.

I deserve more respect but Adcock is right about how things have changed in the past 30 years. Sometimes I coax the Suzuki up to 160km/h to prove it will still do it but the engine complains the whole time. BMW's S 1000 RR will do 160km/h in first gear…

DIVERSIONARY TACTICS
I own a 1999 model Yamaha Diversion with 74,000km on it, but I've had a few problems. In a week of hot weather last January, the CDI unit got cooked. Great. I can get a replacement from Yamaha, but it's over $1000. Ridiculous. I found a used replacement in the end, but now have to confront potential problems with the coils, regulator and alternator. It's all getting expensive. I found someone in NSW who can repair the original CDI unit but even that costs $350. While I have your attention, the cam chain is a bit noisy as well. Can a tensioner be installed and will this solve the problem?
Peter Newell
peternewell58@gmail.com

A CDI unit from a wrecker should set you back somewhere between $150-$250 - cheaper than a repair job and likely to be reliable. Deputy Editor Blackbourn has taken an interest in your letter as the CDI on a XJ750 he previously owned (a close relative of your Divvy) also died. He discovered that excessive charging voltage (over 15V) was probably to blame, so he replaced the regulator as well as the CDI and had no further problems.

You want a charge rate of around 14V. Don't feel you have to change the coils or attend to the alternator unless you have specific symptoms that suggest problems in these areas.

Regarding the cam chain, the Divvy already has an automatic cam chain tensioner. If this is working properly (get a mechanic to check - not a difficult procedure) but you're still getting chain rattle, it's possible the chain has worn to the point were it needs replacing.

It's easy to get cam chain rattle noise mixed up with clutch basket rattle and the noise made by excessive tappet clearances, though, so get your mechanic to have a listen.

Big, air-cooled engines with 70,000km on them will all be a bit noisy, but it doesn't necessarily mean there's something wrong.

WHAT YEAR?
Thanks for your reply to my letter regarding my grey-import Suzuki GSX-R750. Yes, I'd greatly appreciate your help in identifying in what year it was made. I had a look on the net and I'm now more confused than ever. The bike is registered as a 1988 model, but I think this is wrong. The frame number is GR71G-105055 and the engine number is R705-137343. An article on the internet had it pictured next to 1987 specifications. I'm planning on keeping the bike forever so this information is just curiosity.
Paul Weegberg
pjweegs@hotmail.com

Look how much trouble you're causing, Paul. Half the motorcycle industry in Australia is on your case and it may lead to an international incident. Here's the note I've just received from my industry mole, Steve (last name omitted for security reasons): "Hi Spanna, Just letting you know that I haven't forgotten about the ID of that GSX-R750. I found within seconds by checking the frame number that it is a GSX-R750 of 1985-1987 vintage, and that it is most likely a Japanese domestic market model.

"I only have frame number lists for Australian market models, so got on to Suzuki Australia. Suzi Oz knew no more than the above, but is contacting Suzuki Motor Co. (Japan) to see if it can give you the exact year model and market application."

If the information comes through before we go to press, Paul, I'll attach it to the end of the column. If not, keep watching this space. The truth is certainly out there…

ROUGH JUSTICE
Currently I ride a 2008 Suzuki DL V-Strom 1000 and while I think it's one of the best Japanese all-rounders available, it has an annoying problem. At around 3000rpm in fourth gear and doing 60km/h there is a distinct misfire. The problem does not occur if I keep the revs up when riding through a town. Surely a big twin should be able to just burble along at low revs. After a recent service (25,000km) the problem became a lot more frequent and annoying. When speaking to the Suzuki dealer who did the service, I was told that the problem is common in the model due to Australian Design Rules (ADR) which require the bike to run lean at certain revs and the only way to fix it would be to change the engine management unit to something like a "Yoshi" box at a cost of $600!
Have you heard of this problem and do you have any tips on a solution? I'm taking long-service leave soon and heading up to Alice Springs and Darwin for a month. I've had a BMW for the past 10 years and I'm now starting to think I may have made a mistake buying Japanese.
Darryl Low
Millicent, SA

There are quite a few issues here, Darryl. For starters, the Australian Design Rules (ADR) don't require the bike to run lean at certain revs.

One of the tests new motorcycles have to pass to comply with Australian regulations is a noise test. This test is in two parts: a static noise test and a ride-by test. I'm simplifying a bit here, but the ride-by test for a bike like yours involves riding from one line on the test area to another (a distance of 20m) under full throttle in second and then in third gears. A microphone at a certain distance from the bike records the noise. It can't exceed 80dB(A) averaging the results from the two gears.

The noise measured isn't just exhaust noise - it's also mechanical noise. Bikes with full fairings have an advantage here in that the noise they produce is somewhat muffled by the bodywork. Large capacity, air-cooled (and liquid-cooled) naked bikes (have pity on Harley-Davidson) often struggle to stay within the limits.

It doesn't happen as much now with the widespread use of electronic fuel injection, but it wasn't uncommon for bike importers to 'tune' new models to lean out the fuel mixture at the point at which noise was going to be measured.

If, for example, a test bike crosses line A doing 3000rpm in third gear and finishes at line B doing 4000rpm, leaning out the mixture in this rev range will produce a quieter result. It also produces a flat spot in the power delivery, something the government doesn't care about but something new owners are often surprised to find.

Distributors must sell the bike that passed the tests without alteration, but the flat spot can often be tuned out afterwards or remedied by an alternative exhaust system and tweaks of the fuelling.

Understandably, distributors are reluctant to discuss what they've done to individual models to get compliance, but if your dealer has told you part of your problem is special tuning to get ADR compliance, it could easily be the case.

Two other things: the engine management system on the DL1000 isn't quite as sophisticated as others on offer today. The model has been around since 2002 without much development. The transition from low engine speed mapping to higher engine speed mapping happens at around 3000rpm, and if you sit on these revs in certain conditions for any length of time, the black box can get a little confused.

Lastly, Suzuki has dialled in retarded timing to various degrees in each gear, along with a speed limiter in top gear. This has been done to manage performance, but if you fit a timing retard eliminator (TRE) you'll get crisper performance in all gears and it will help remedy your current problem. TREs are relatively cheap (GIpro has a good reputation and costs around $220. It's also easy to fit.)

The cheapest way out of your current dilemma is just to ride through towns in a lower gear with higher revs. A dyno tune will get the best results from the current specs on your bike, and a TRE will give you an inexpensive performance boost.

As you've probably already discovered, the DL1000 is a much-loved bike among its owners, particularly those who do big distances and carry lots of weight. It has its idiosyncrasies, but that's what gives a bike character.

TOUGH DECISION
I'm currently torn between buying a new Suzuki Bandit S (or a low kilometre, second-hand one) or a 2001 BMW K 1200 RS. The BM has 65,000km on it but I know the owner and the bike has been pampered. I'm leaning towards the BM but am wondering if there are any inherent faults with this model? Everyone on the internet says it's a great bike and potentially good for 300,000km-plus.
I'm particularly concerned about running costs in comparison to the Suzuki. Any feedback would be greatly appreciated.
David
david@hgco.com.au

This is a tough one, David. The answer will probably depend on what you want to do with the bike. Will it be used for weekend rides, special events, and the occasional longer tour or will its duties include daily use, city work and lots of kilometres?

The BM has lots of class and is a physically imposing motorcycle. It's big and heavy (285kg) but it's also fast and comfortable. Running costs will tend to be higher as replacement parts are generally more expensive than those of bigger-selling Japanese bikes. Yes, sticking to BMW's service schedule will cost you more, but it pretty-much ensures reliability and long service life. If you're a weekend rider, you might lean this way.

If, though, you'll be using the bike for commuting and touring (and a bit of scratching), the Bandit S has a lot to offer. Every time I get involved in the usual drunken argument that starts, "If you could only own one bike…" a Suzuki Bandit is always close to the top of the list. The half-fairing on the S provides some weather protection and aerodynamics, which is arguably a weak spot in the fully naked versions. Being new or near-new, running and maintenance costs will be lower and relative depreciation will also be lower.
As I say, a tough question.

LIVING WITH A KINLON
In MT #223, you ran a letter from a bloke named Joe which painted a pretty optimistic picture of what Kinlon RT200 owners can expect. Prior to this, I had a low opinion of Chinese bikes, but on the basis of Joe's opinion I purchased a sparkling, new, 2009 model. I work in the aircraft industry so my standards and expectations of anything mechanical are probably higher than that of your average punter, but I think some of my experiences need to be shared. Joe recommends regular service intervals and he's got my total agreement on that score. My bike is now nudging 4000km which has mostly been 70km daily commutes. It has been brilliant mechanically. It has never failed to start, runs reliably, is very good with fuel use and, apart from a lack of power due to its microscopic engine capacity, I can't say a bad word about the engine. My problems have come from the materials used and the build quality of the rest of the bike. You wouldn't expect corrosion to be an issue on a bike with such low kilometres, but some of the parts that have been painted or chromed are showing signs of surface rust. More worryingly, while cleaning the bike up a bit I noticed pitting and the start of corrosion on the front fork tubes. This bike has never left the blacktop! Maybe Kinlon's hard-chroming isn't up to scratch, but roll this in with perishing rubbers everywhere, broken fairings, exhaust paint that flakes off the first time the bike was ever started and you have cause for concern. Yes, the engine is good, but how much value is there in a reliable engine mounted in a frame which isn't going to go the distance? Several critical fasteners have also rattled out, and it's a good idea to replace the critical ones with better quality items. My advice to anyone contemplating one of these machines is to ensure you understand it's a cheap item and you're getting exactly what you pay for. A $3000 bike is only a bargain if the bike doesn't fall to bits. The bike does, however, provide an inexpensive form of commuting and it's safer than a scooter of a comparable price. Once it's paid for itself in saved public transport cards, I'll try to unload it, although second-hand value will be an issue.
Steve Patterson,
ear_spear@yahoo.com.au

Thanks for this, Steve. Readers toying with the idea of a Chinese bike will appreciate your experience, although as you say, you're probably inclined to be a bit more demanding than your average punter.

I'm currently keeping an eye on two Chinese bikes: one a Kinlon RT200 and the other a Sachs 150. I've done road tests of both in MT and on both occasions had problems with poor pre-delivery. I did my best during the tests to hurt the engines, but couldn't, again confirming your views.

No Australian development work was done on either bike and I noted at the time that the jury would have to stay out on how the bodywork would stand up to Australia's harsh climate. Fairing cracks might have something to do with too-rigid mounting, but could also be related to the plastic suffering UV light deterioration.

In China the Kinlon and the Sachs are assembled usually by the engine company but using outsourced running gear. The quality of some bits of the bike will differ to other bits. Sachs has a more 'whole of bike' approach but it's still China, not Japan.

The bikes I'm monitoring are doing surprisingly well but both are garaged when not in use and are probably being better looked after because the owners know I'm watching.

I think the Sachs 150 in particular is currently very good value for money. Many riding schools are now using them and they seem to be responding well to what must be a hard life. As news comes to hand with the bikes I'm monitoring, you'll read it here first.

OLD GOLD
I have a question about my late grandfather's motorbike. Mum gave me a photo the other day of grandad on it but she can't remember what sort of Harley-Davidson it was. What she can remember, though, is going with him in a sidecar when she was young. Now, being the gentleman I am, I won't disclose my mother's age but I'm a sprightly 41 and mum's mum is nearing 97 (she won't mind me telling you). Grandma can't remember either so I thought I'd ask you. To me it looks like a late '20s - early '30s model and the front tyre seems to look like it may have been there because of sidecar use.
Stephen Gould
steveirene96@bigpond.com

Nice picture, Stephen, and I hope we can do it justice here. There might be someone in Australia who knows more about old H-Ds than David Reidie from Harley City in the Melbourne suburb of Brunswick but if there is, I haven't met him yet.

Based on the headlight arrangement, Dave says it's a '29 model which was very popular in its day. Most of the '29 models had the 74 cubic-inch (1200cc) engine but it's hard to be sure from your photo. Good luck finding one but, if you do, be prepared to part with $20,000-plus for a good one.

Among other duties, my own father was a dispatch rider in WWII. I wish I had a photo of him aboard his trusty BSA. Don't lose the photo of your Grandad.

MORE OLD GOLD
I recently found a nice, old Honda CB750K7. I like the old-style look and considered buying a modern 'classic' but was put off by the concept of paying top dollar for an outdated design. I know you get modern internals and such but that just seems to clash with the classic bike thing. Anyway, I bit the bullet with the CB and now I have to fix it! It has a huge flat spot from about 1500 to 3000rpm. Over that it runs sweet as. The points and plugs look to be in good order but I haven't had the timing checked yet. The cam chain is very loud at idle but barely noticeable at higher revs. The bike was unused for ten years before being cleaned up and sold to me. Should I just ride it for a while to see if the flat spot gets any better or stock the beer fridge and get to work in the shed? Both options sound good to me.
Fred Beck
beckfred@qld.chariot.net.au

Nice decision, Fred. You could simply sit in your well-stocked shed and watch the value of your investment grow but, clearly, you want to ride it too. Here's what you should do.

Clean the bike thoroughly. Then change the engine oil and filter (CastrolActiv4T is good) after a run.

Replace the brake fluid with DOT 4. Check the brake pads, and you'll need new tyres, too (the old ones will have no grip after 10 years).
Check and adjust valve clearances, fit new points, condensers and plugs and check the timing. Get someone with the right equipment to balance the carbs for you.

The flat spot is either because the original air filter system is leaking big-time or, more likely, it's been replaced by an alternative system (usually pod filters) without adjusting the carburetors.

Look for an original airbox and air filter system - might be a bit expensive but I know they're available - and fit it, making sure there are no air leaks.

A stock exhaust system is also good as some aftermarket ones will create flat spots without carb tuning to suit.

All this will keep you busy for a while but will produce a ride with all the pleasure and reliability of the original bike.

Oh, one last thing: make friends with Andrew at Pud's (Four) Parts (03) 5182 5704 as he's the country's best stockist of single-cam Honda Four bits, including, incredibly, original exhaust systems for the K7.

You've reminded me, Fred, of how much I need a single-cam Honda CB750 to add to my modest private collection.

F1s and F2s for some reason (ugliness perhaps?) seem to be cheaper at the moment than the K-series bikes so it might be one of those. The engine in the

F2 was the most powerful of single-cam series.