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Startup Problems - Part 1


There's never a good time to find your bike refuses to start – and it usually happens when you least need it.

"Yesterday the engine was running as smooth as silk and now, when I've got an urgent meeting to get to, it's as dead as a dodo." There's simply no predicting malfunctions, be they big or small. The following "First Aid" check list is designed for those "minor" niggles, and hopefully will help get you to the church on time. But: It's no good if your battery is as flat as a pancake. In that case you have no choice but to charge it – and there are simply no corners to cut there.

kill switch
Kill switch set to "RUN"?

Kill switch set to "RUN"?

You'll find the kill switch on the right handlebar, generally marked "RUN" / "OFF". However, the majority of bikers virtually never use this alternative "emergency ignition on/off switch", so that they don't even think about it. And there are always a few jokers around who think it a great prank to switch it to "OFF" in passing. But the mean thing about that is that while the starter motor still operates, the ignition current has been cut off. And more than a few bikes have been pushed to a workshop as a result! ...

spark plug
Spark plug connectors secure?

Spark plug connectors secure?

The same jokers may think it equally funny to pull a spark plug connector from the spark plug - a good reason for checking that all the engine's spark plug connectors are secure. Are the cables securely attached to the connector and are the connectors tightly fitted on the plugs?

side stand
Switch on the side stand dirty?

Switch on the side stand dirty?

The safety switch on the side stand is designed to prevent you riding off with the side stand down. It is fitted on the side stand bracket, and is therefore very exposed to moisture and dirt from the street. However, a malfunction here is actually easier to spot than on the kill switch because nothing happens at all when the starter button is pressed. The first step would be to carry out a visual check. And even if the side stand appears to be correctly folded up, a millimetre of mud and dirt preventing the switch from reaching the correct position can make all the difference. If this proves to be the case, clean it with whatever you have at hand – a cloth/towel or a drop of penetrating oil or contact spray.

neutral engaged
Neutral engaged? Don't rely on your Neutral indicator!

Neutral engaged?

Even when the indicator lights up, sometimes neutral is not actually engaged properly. On some bikes, this disconnects the ignition or starter control circuit, but on others the bike may jump forward if it is in gear and the starter is pressed. For safety, it is important to check briefly whether neutral really is engaged.

board equipment
All energy guzzlers off?

Are all energy guzzlers off?

Some ignition systems are more than a little egoistic when it comes to battery power. Now, if the battery is not in peak condition, or if it is trying to supply other devices at the same time (lights, heated grips, etc.), it may mean that the ignition spark produced is not strong enough to start up a cold engine. So it's important to switch off all other devices during startup.

ignition switch
Ignition switch contact problems?

Ignition switch "contact problems"?

Briefly switch on your headlights and check whether the light is weak or flickers when you jiggle the ignition key. If so, spray a little contact spray or penetrating oil in the lock. Generally, that will fix the problem – if not, you may need a new ignition switch.

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fuel tank cap
Enough petrol in the tank?

Enough petrol in the tank?

"I can hear splashing in the tank, so I'm bound to have enough fuel." Not necessarily! Most tanks have a tunnel-shaped recess in the middle designed to create space for frame tubes, air filter housing or other components. The fuel cock is on one side, and it is on this side of the tunnel that the fuel level may already be too low. You may hear petrol splashing around in the tank on the other side, but the tunnel prevents it getting across to the fuel cock side. Sometimes, by tipping the bike on its side (in the direction of the fuel cock – and don't forget that your bike's heavy!), you can shift the last drop of petrol over and use it to get you to the filling station.

petrol cock
Got there on your last gasp?

Got there on your last gasp?

Sometimes it happens that you get to your destination literally with your last drop of fuel. And before the engine dies, you switch off the ignition. Made it! But when you try to start up next day, she's as dead as a dodo. Maybe a cough and a splutter, then silence. Simply switch to "Reserve".

Choke fully functional?

Choke fully functional?

A cold engine can't start without the help of a cold start system. Especially if the choke is cable actuated via the handlebar, it can jam or become stretched over time, so it no longer works. If there is reason to think this is the case, follow the cable from the handlebar back to the carburettor and check whether it's still working. If it is jammed, you will need to thoroughly lubricate the cable. Penetrating oil is often a quick solution to the problem. If the cable has stretched or is fraying, you will need to replace it.

fuel filter
Air bubble in the fuel filter? Kink in the fuel hose?

Air bubble in the fuel filter? Kink in the fuel hose?

A large air bubble in an external fuel filter can certainly interrupt the flow of fuel to the carburettor. At the carburettor end, slightly loosen the hose at the filter while the fuel cock is open (if it is vacuum operated, set it to "PRI"). This will force the air through – then quickly push the hose firmly back onto the filter so that you don't lose too much fuel. Always take care to avoid skin contact with fuel. A kink in the fuel hose may also stop the flow to your engine, so it is important to ensure the fuel hose isn't bent in too tight a radius. If that is not possible, it may help to feed the hose through a spiral spring.

Carburettor frozen?

Carburettor frozen?

The evaporation of fuel in the carburettor produces evaporative chilling and heat is drawn from the surroundings. Particularly when the weather is very humid and temperatures are only slightly above freezing, carburettors may occasionally freeze up – which will either prevent the engine from starting, or it will start but quickly die. This can be remedied by applying heat, and a fuel additive like Procycle fuel system cleaner can be used as a preventive measure.

diesel in the fuel tank
Filled up with diesel by mistake?

Filled up with diesel by mistake?

"Could never happen to me"! Famous last words... It's happened to the best of us. You're out and about, in a tearing rush, need some petrol and before you know where you are... Best do the smell test. And if it is diesel in your tank, you'll need to find another way of getting to your next appointment, because draining your tank and the carburettor float chambers is going to take a while. And the same applies to a thorough inspection of your ignition and carburettor. If our check list hasn't got you up and running yet, go to Part 2 of our handy tips for solving start-up problems …

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the experts

The Louis Technical Centre

Problems getting spare parts? Or maybe you've got a technical question about your motorcycle or an accessory The Louis Technical Centre can help! Remember to quote all the necessary details of your vehicle – better still, send us a copy of your registration document.

We will get back to you as quickly as possible!

So: send us your technical problem!

Please note!

These tips for DIY mechanics contain general recommendations that may not apply to all vehicles or all individual components. As local conditions may vary considerably, we are unable to guarantee the correctness of information in these tips for DIY mechanics.

Thank you for your understanding.

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