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Hey there everyone! this is my first post. I am desperate at this point. I have a 2012 CBR250r. i’ve done all work myself and do the same with dirt bikes but I am completely lost. I found one person ever with the same problem online and it was posted on here two years ago but no one ever had an answer, I figured I would try my luck. I got the bike, it ran fine and all then one day when turning on the ignition switch, it made a loud buzzing from under the fuel tank and doesn’t turn over. It does the buzzing everytime I switch on the ignition switch. I switched the fuel lines, and the whole fuel pump assembly and it was still doing the same thing. Someone told me maybe the relay wasn’t getting g enough power or the fuel pump wasn’t either so today I went and bought a brand new battery, still same problem. I am totally lost and desperate for answers at this point. I have a video (not mine, it’s from the original post I saw from two years ago that never had an answer).

anything helps, thanks in advance!
 

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Is buzzing when you turn on ignition switch? Or when you hit start button? Video clearly shows nothing happens when ignition switch is ON, and only buzzes when start-button is pressed. AND bike in that video cranks engine 2nd-time around. Does yours behave exactly like this?

Problem is low battery. How long did you charge new battery? New battery comes in discharged state and must be charged for 24-hrs too. Could've charged old battery to fix this problem. Buzzing sound is your starter solenoid not getting enough power from battery.

1. measure battery voltage with bike off. What is voltage?
2. Measure battery voltage when pushing start button. What is voltage?


This is beginning, we might need to test wiring, stator and R&R condition. DON'T replace any part until you've tested it and confirmed it's bad by comparing numbers you've measured with manual. Otherwise you can be replacing hundreds of good perfectly-working parts with brand-new perfectly-good parts and nothing changes. Would be cheaper to just buy another bike whenever something goes wrong.
 

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Discussion Starter #3
Problem is low battery. How long did you charge new battery? New battery comes in discharged state and must be charged for 24-hrs too. Could've charged old battery to fix this problem. Buzzing sound is your starter solenoid not getting enough power from battery.

1. measure battery voltage with bike off. What is voltage?
2. Measure battery voltage when pushing start button. What is voltage?


This is beginning, we might need to test wiring, stator and R&R condition. DON'T replace any part until you've tested it and confirmed it's bad by comparing numbers you've measured with manual. Otherwise you can be replacing hundreds of good perfectly-working parts with brand-new perfectly-good parts and nothing changes. Would be cheaper to just buy another bike whenever something goes wrong.
I did charge the old battery, charged it overnight. it was at 12.7 volts when charged and while trying to start it
 

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Post video to YouTube. Then post link to it here.

12.7 volts just off charger is dead battery, so getting new battery was probably necessary. But did you charge new battery?

Trace fat battery cables to other end, positive should go to starter-solenoid, negative to engine block. Disconnect those ends, lightly sand them and re-install.

1. What is voltage of new battery before cranking?
2. What is voltage of new battery while pushing start button?
 

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Another test is to jump-start bike from auto-battery of car that starts. Leave car OFF when connecting jumper cables to bike.

3. measure voltage of car battery. What's voltage?
4. measure voltage of car battery when pushing start button on bike. What is voltage?

Useful analysis to compare numbers from #1 & 2 versus #3 & 4
 

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Test both old and new fuel-pumps. Unless you bough brand-new OEM fuel-pump from authorised Honda dealer, new-pump is suspect. So many crappy 3rd-party aftermarket parts are bad brand-new right out of box! They too must be tested and verified good before using.

1. disconnect fuel-hose from fuel-rail and aim into measuring cup
2. turn key ON
3. hit starter-button

Do you have petrol in measuring cup? Repeat test for other pump.
Now you know for sure if new and old fuel-pumps are good or bad.

BTW - this is only cursory test. There's also real test of whether pump can flow at required pressure.
 
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