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Gas tank problem

jiggsgoes_

New member
Joined
Jun 10, 2025
Messages
2
I'm not sure if I should be posting this here but anyway.. My 2017 CBR 125R refuses to start when the fuel tank is connected! However, if I bypass the tank and feed gas directly into the carb from a bottle, it fires rights up and runs pretty well. I'm completely stumped! It has only run for less than 8200KM.. It has a new battery and I've already cleaned the carb. When I bought this, I was told fuel pumps rarely go bad on this model so I'm not sure if I should suspect that's the cause.. Any ideas on what could be preventing fuel from getting from the tank to the carb?
 
Since it runs fine when bypassing the tank, it sounds like a fuel delivery issue to me. Try checking the fuel pump or any clogged fuel lines? might be a venting problem too, try opening the gas cap and see if it makes a difference. Let's see what the others say too
 
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