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Troubleshooting Having trouble with your bike? Common know issues or trobuleshooting questions here.

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post #1 of 3 (permalink) Old 05-23-2015, 07:46 AM Thread Starter
Training Wheel Hero
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i have a 2000 cbr600, its carborated.
i just started it for the 1st time this year. it took quite a while to get going i tried it with and without the choke. sometimes it would back fire with a very loud bang. it did finally start and then it ran fine.
why would i be getting backfires?
i assume that its too rich and the fuel must b getting into the exhaust?? but why??

Last edited by mark1200; 05-23-2015 at 08:53 AM.
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post #2 of 3 (permalink) Old 05-23-2015, 10:56 AM
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Well, when you crank the bike, you're spitting fuel into the cylinders. When it doesn't start right away and you keep cranking it, you're adding more and more unnecessary fuel into all 4 cylinders from all 4 carburetors. Sometimes you can flood the bike, but you can also ignite it too. When the exhaust valves open, all the extra burning fuel exits through the exhaust. You can also spit unburnt fuel into the headers along with it and have it ignite and pop, crackle, gurgle, burp and spit flames. Wouldn't worry about it too much if it's running fine now. Who knows, might be time for a carb cleaning and synchronization.
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post #3 of 3 (permalink) Old 05-24-2015, 09:06 AM Thread Starter
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i understand the end result.
thanks for the explanation.
i am more concerned about why it didnt want to fire up right away , which would avoid the flooding.
if the carbs r dirty ,in my experience the bike wont fire at all because there is no fuel.
i had to clean them last year do to this.
any in depth info on this subject would be greatly appreciated.

do u think having last seasons premium fuel in the tank would be a problem?
last year the 2 ,05cbr600 fuel injected bikes i care for, fired right up but the 2000 carbed bike would not fire, untill i put new fuel in it. i guess i should start draining the fuel every fall.

i am having a hard time getting good info on fuel quality and its longevity.
i now use Petro Canadas 94 oct premium. i make sure to put a few litres of fuel in my truck before i fill the gas can for the bikes, just to be sure there is no reg fuel getting into my gas can.
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