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Me and my brother have been working on his bike since he had an accident and we noticed that when you start up the bike fuel and oil are being forced from the carburetor into the air intake box does anybody know why this might happen or what we should do
 

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More details might be helpful. I'm not sure why oil and gas would go backwards from the carb to the air filter???

If oil is coming into the air filter, it's usually because oil has gotten into the vent on the top of the valve cover. More might have gotten into it when it was laying on its side. Or, if the oil was just changed, then there might have been too much oil put in and the excess is being blown out.

Gas could be somewhere if it ran out of the carb or gas tank when tipped over. There could be excess gas if a choke (or enricher) was stuck on and the float was overflowing maybe through a carb vent overflow line. Normally the only way to get gas into a carb is through the hose from the gas tank. If you have a fuel pump that was stuck on, that might cause an overflow.

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Very good info for you Viking!

Welcome to a great forum.
61201


Sam:)
 

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When I ran out of fuel in my 79 XS1100, and then poured fresh gas in the tank and opened the petcocks, fuel leaked from the air filter. The cause: The floats dropped to the bottom of the fuel bowl. When the petcocks were opened and fresh fuel flowed in, one or more of the needle valves stuck, as it was trying to reenter the tube that it slides up and down in. The fix: Tap the float bowl with the kick starter lever or something similar.

When working on carbs, you will notice that the needle valve can stick like this at the bottom of its travel. It happens.
We need to be sure it is moving up and down freely. The crank vents in to the air box. Over time an oil residue coats the inside of the air box. Add some fuel to that, and it dissolves the oil residue. If there is a lot of oil residue, it means more pressure in the crank case, which is caused by compression gas going past the rings. Low compression would be a sign of this.
UK
 

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WELCOME ON BOARD, and...

We are friendly site here. Well, most of us?
 
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