carb problem

[gs425e]

i have stripped and cleaned my carbs gsx550e 1983 fitted new plugs, new plug leads and new air filter the bike started and ran fine then 3 days later it refused to start and all it does is backfire the 2 plugs on the right hand side are black and the two on the left are clean just as i had cleaned them getting a good spark any help greatfully recieved cheers andy

[KEITH KRAUSE]

Could be anything from poor compression to a simple mixture screw adjustments. Did the bike run good before you worked on it or did you inherit this problem? Backfiring is generally related to raw fuel collecting in the cylinder/exhaust, but can also be ignition/timing related.
Simple check...where are the mixture screws set at?
Also, were the carbs bench synched? Valve clearances checked? Have you verified ignition advance timing and operation?

[gs425e]

hi the bike had stood for two years but ran i cleaned the carbs etc,etc and the bike ran fine then stood for 3 days and failed to start it also has a new battery and now almost fires but not quite why would it run one day and then not the next wil i have to strip the carbs again..andy

[fgh]

If your bike has the same coil configuration as mine then it uses both coils to fire the right side cylinders. If thats the case you probably don't have an ignition problem. Since both right plugs were black it sounds very much like a stuck float flooding the right side or a stuck main jet piston.

If it was running fine when you parked it and does this when you try to start it it makes me strongly believe you have a stuck float. It could also be a bit of dirt or debris lodged in the float valve.

These fuel resoivors can overfill slightly or can leak constantly. Can you smell gasoline when standing next to the bike? Is there gas dripping on the ground? Does the oil smell of gas? Has the oil level mysteriously risen since you parked it?

[chef1366]

You might have a bad petcock. Smell your oil and see if it smells like gas. If it does change your oil and your petcock.
Mke sure your petcock is not on prime. It will fill your crankcase with gas and cause vaporlock and will not start.