DRZ400 turning over but no ignition

**Box of riddles** · 5th March 2013, 18:35

Hey fellas, I'm having an issue with my '06 DRZ400SM and was wondering if anyone had some bright ideas.

Last week I had just finished an overtake when the engine cut out, and since then it's been refusing to start.

I've changed the spark plug, checked it's getting fuel through the carby via the drain line and checked my air filter. When I'm turning it over it sounds like the spark is just a little too late and it'll occasionally backfire.

Any and all ideas are appreciated.

**davereid** · 5th March 2013, 19:38

You can check the spark by putting plug on the head and cranking the bike over - a nice fat spark is what you are looking for. This does not check timing, which can be responsible for backfiring, but so can crappy mixture.

Lots of mechanics like to use ether - start ya bastard or similar. The idea is not to mask a fault, but to help pin it down.

For example if the bike starts ok with a spray of ether down the aircleaner, problem is likely fuel related.

If spraying ether around the inlet manifold works, you have an inlet manifold leak - bike too lean to start.

But ether is not good for motors - use it sparingly as part of a diagnosis rather than as a repair !

**spanner spinner** · 5th March 2013, 19:42

check the basics do you have spark, do you have fuel (and not just in the carb is it getting in to the cylinder) and do you have compression? If you think the spark is late turn the motor to TDC by taking the plug out turn the motor over with a screwdriver in the plug hole to find TDC then check that the tdc mark on the flywheel window lines up, the flywheel may have turned on the crank. This is not very common but does happen and this will alter when the plug fires.

**Box of riddles** · 6th March 2013, 16:09

I have fuel getting to the cylinder, as when it backfires it shoots out lovely jets of flame.
Compression is there, and I'll give the flywheel thing a shot.