Question about 1977 Honda Cb 400 F

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It cranks good...idles good...will not take gas...i cleaned the carbs...and put new plugs acts like the right cylinder is not firing's exhaust is almost cold ...the right cylinder pipe will get red pops when throttle is applied...all boots look good...can anyone give me some help?

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  • cheap repair Jan 03, 2011

    that cylinder is running lean. The carb is clogged up or does not have the right float height setting.

  • cheap repair Jan 03, 2011

    make sure your fuel tank petcock is not clogged with rust or other debris and that you have proper flow of fuel to the carbs.


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Cylinder head is getting red hot because it's running lean. Check to see if there is an aftermarket fuel filter in the fuel line somewhere, also the float hight in the carbs are set right. Also drain the fuel tank and apply fresh fuel. Check to see if the tank is rusted, also if it has a device at the bottom of the gas tank that turns on and shuts off the fuel (petcock) it's possible it has a fuel flilter in there as well.

*Note if you take the petcock off you will more than likely have to replace agasket for it. Given the age of the bike it will be hard to find a gasket.

Posted on Jan 03, 2011

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  • evoss124 Jan 03, 2011

    what about the cylinder that runs cold exhaust?


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If I can help some more just send message.

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