It’s a nightmare; you step outside on a sunny morning in full gear ready for your commute to work, throw your leg over your pride and joy and put the key in ready for that familiar purr of the engine. But there’s no purr. That’s when you realise your bike won’t start, you try a couple more times but nope, that machine is going to nowhere so, what do you do now?
If there's no time to call out a motorbike engineer before work or you just can’t afford it, then you’re going to have to try and tackle the problem head on. If your bikes problem isn’t too serious you might be able to fix it yourself which will 1. Save you some money and 2. Get you on the road in time.
Most of today’s motorbikes need 3 basic things to get started; these are spark, fuel/air flow and compression; if it’s not got one these it won’t budge anywhere. When you break down these three components, it is a lot easier to see why your machine isn’t moving.
Spark Plugs
The electrical issues with a bike are usually the most annoying to a biker to deal with, it’s something we take for granted all the time but in reality we don’t know a lot about. First things first makes sure to rule out any basic issues like the position of your key and kill switch, it might seem pretty obvious but it’s always worth checking before you start digging around in your bike!
So it’s neither of those, now we need to delve further into your electrics. Start at the spark plugs, from here you can trace all the way back to find any ignition problems. To test the spark plugs, take them out of the cylinder head and plug them back into the plug cap. Next you’ll want to hold the plug up against some sort of metal (think bolts, screws etc.) and turn on the engine. If you can’t see any spark or if the spark is a bit weak, change the spark plugs, if the bike still doesn’t work move along the electrical system. Give all the plug wires and caps a good check, if you think these are the issue you can run a quick OHM test on them.
Air/Fuel
Again make sure all the obvious things are covered, there’s petrol in the tank etc. If your bike has been sitting for a while unused, it can cause petrol in the tank to break down and it won’t combust, so ensure there is fresh fuel in the tank. Another issue with sitting, is that it can really dry out your fuel system - you might need the help of starting fluid or carb cleaner sprayed into the carb intake - this should draw fuel out of the tank once its fired up. If your bike still isn’t working then try checking a couple of these issues:
-A clogged vent tube
-The engine might be flooded, if it is unflood it by taking out the spark plugs turn off the choke and flip the motor over so the extra fuel is dissipated.
-Clean your carbs out. When fuel breaks down it can leave gross green gunk in the carburettor and block the jets.
– Check for broken or loose vacuums. The engine needs the right amount of air to be mixed with the fuel. If a vacuum line is broken or loses too much air it can be drawn into the combustion chamber.
-Check your vacuum line for cracks and holes, this can cause small amounts of air to be pulled into the chamber.
Compression
Checking the compression should be the very last thing to do when you trouble shoot your bike. If one of your cylinders has low compression your engine won’t fire up right (or not at all). Checking the compression can be a bit trickier and requires you to have a compression tester. Anything from worn out piston rings to scored cylinders can cause this.
At this point, it’s probably where you need to hold up your hands in defeat and get the experts involved.
One last check, I know we mentioned it at the start of the article but check your kill switch isn’t set to off!
