Backfires when cold starting

[brucy69]

Hi Lads and lassies,

Recently my GS500 2002 has started backfiring. on cold mornings it takes a while to start and then I get a couple of massive explosions like a shotgun. Any idea what might be causing this

cheers

[Kijona]

Does it run fine otherwise?

Cold air is denser than warm air. You have a fixed ratio carburetor.

[gsJack]

Hi Lads and lassies,

Recently my GS500 2002 has started backfiring. on cold mornings it takes a while to start and then I get a couple of massive explosions like a shotgun. Any idea what might be causing this

cheers

Caused by plug missfiring due to cold and unburned fuel mixture entering exhaust and when plug finally fires it ignites the unburned mix in the exhaust system.

If plugs, valves, full choke, etc are good it will be minimized but my 02 still does it occasionally when it's very cold out.

[brucy69]

Yeah it runs fine otherwise, no problems on the road or later in the day. Ill change spark plug anyway and see if that clears it up. Thanks lads

[Janx101]

Brucey. .. regarding your initial post....

I myself am like that! ... first half hour on the trucks in morning .... lmao. .

Gets worse if I drink redbull..... make sure you keep the bike.clear of energy drinks! .... bahahaha..... oh Damn I'm tired!

[rg500gamma]

Hi all  , +1  to gsjack

[MeeLee]

mine does it too, when it's 'cold' (45 in florida is cold), and I rev the throttle

[bryan88]

I have been having this problem with mine and think (hope) I have found the problem. Check the wires coming from the switch cluster on the throttle side for corrosion. You have to actually bare the wires as a tester will show continuity but it's not enough to feed good current to the coils. Mine were all rusted under the insulation so I soldered new wires from where I could find a non rusted spot (worst case scenario, you would have to solder the new wires to the switch itself, unless of course you just replace the switch) It hasn't got really cold here yet so I can't say if this is a definite fix for now, but the bike is starting much better.