Strange Noise from engine

[z1000puddin]

Guys,
Looking for some help on my zed 1075.

With the engine cold ( not run for two days)
If I switch on the ignition key & without starting the engine, switch the key off.

I get a strange "Phhluff" from the engine for a split second.
(sounds like it comes the combustion chamber)

If I switch the key on again, even after a few minutes- The strange noise does not happen

The bike starts, runs & goes well with no other weird symptoms.

Stu

[Mark Tiller]

Mine does the same

[zed1015]

You have Dyna 's' ignition fitted ??
If yes then this is normal and it's just the spark igniting fuel residue in the cylinder.
All my zeds with Dyna's do this .

[GIMPieZ650]

As said, common dyna-s characteristic, nothing to worry about. sometimes you get a nice pop and a little flame if its hot

[z1000puddin]

Aha,

Yes Dyna S fitted.

Thanks guys