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1997 Yamaha 25hp bottom carb not getting fuel

irizarry44

New member
Hello,

I have a 1997 Yamaha 25 hp two stroke outboard motor that the carbs were rebuilt. The bottom carb is not getting any fuel. The top carb gets fuel and the motor cranks right up. I have replaced the fuel lines as well but the bottom carb is still not getting fuel. Has anyone had this happen? I have tried everything can anyone help me? Thank you in advance.
 
The needle valve in the bottom carb might be stuck in the closed position and is not allowing fuel into the carb. Generally when the needle valve starts to stick closed, it will need to be replaced.
 
I would also start by checking the lines from the fuel pump. When diagnosing this type of problem it is good to start at the beginning and verify that fuel is making it to each next stage, finally ending at that needle valve.

Stuart
 
I would also start by checking the lines from the fuel pump. When diagnosing this type of problem it is good to start at the beginning and verify that fuel is making it to each next stage, finally ending at that needle valve.

Stuart

I agree with DangarStu...start at a point known to not have an issue and work toward where there is one.
 
Thank you guys, I will check the needle. All hoses have been replaced, its weird the top gets fuel but the bottom gets none.

A stuck needle valve may very well be your problem. If it is stuck, it will not allow any fuel into the carb. A stuck needle valve is a curse of 2 stroke engines. Usually during a carb rebuild (like yours were), the needles are generally replaced as a matter of course. Yours might not have been. Please check it and let us know how it goes.
 
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Take the fuel hose going into the bottom carburettor and put it in a jar then crank the motor with the ignition off (kill switch out). If fuel comes out the fuel hose then it is definitely your carburettor needle valve. If nothing comes out it is probably your fuel pump given you have replaced the lines. I have had lines that were new, but had been lying around the workshop for a while and insects had made nests in them. Just because they have never been used doesn't mean they aren't blocked!

Stuart
 
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