The fuel pump doesn't come on unless the engine is running.

There's a procedure in the manual for testing the pump by hampering wired.

 

You nailed the head reinstallation on the money so shouldn't be the valvetrain making that noise and preventing the engine from running.

Just have to sort the fuel pump to see if it is in fact bad.

 

So i just checked the fuel pump using a battery and the fuel pump is indeed working as intended. I also removed the carbs and i found a neat little surprise. not sure if this is whats causing the problem but would love to know if it is. I removed the top covers from the #4 carb (the one that had the bad float bowl) and i found this vacuum spring complete destroyed. all the other carbs look great though besides a little gunk but i will be cleaning that out very well but even the gunk its very minimal. so not sure if the spring is whats causing the issue or if there is something else deeper into it.


i should also mention that when i removed the carbs and flipped them upside down a lot of gas did spill out so gas is definitely making its way to the carbs.

 

Wow, that is pretty mangled. That could certainly pose a problem.... but figuring out why it happened to prevent it from happening again could be a challenge or maybe it was just a fluke.

If that spring is not holding the main jet closed necessarily and with the vacuum slide loose, it sure could pop up and down and be responsible for making that racket.... additionally when the bike is just at idle, the needle jet should be basically closed closing off the main jet.... if the spring can't keep the slide closed, thus keeping the needle jet closed closing off the main jet, it is possible to suck in a bunch of fuel... too much for just idling .... flooding that cylinder and end up shutting down the bike.

If that is only the problem, then that would be cool. If you fix that and still struggle to idle smoothly, I would look at a good deep clean on the pilot jets. Those are very small orifices and VERY prone to gumming/plugging up.

Let us know how it works out after you replace the spring.

 

Update: So i took all the carbs apart and soaked each one for 24 hours as suggested and i also order brand new jets for all the carbs and installed those aswell as well as floatbowl screws. I also checked and made sure all the carbs were back in sync after putting them back together. After putting the carburetor back on the cbr and setting everything back up the bike wi not start but im not even getting an idle on the bike. Not sure if thats just cuz the gas isnt in the carbs yet and need tl give it time or if its just not working. I made sure to watch the carbs to make sure there was no leaking of any kind during my start attempt and there was nothing. No leaks and all hoses are working. I will keep trying and update if it does start but any ideas are welcome.

 

Hi Nick.

You said it will not start? Or it will start but not idle correctly?

Your fuel pump should fill the float bowls pretty quickly so that should not be the issue, but I say shouldn't cause bikes can do some screwy things.

Did the knocking noise at least go away?

Only thing I can think of trying and have to be very very careful is shooting a super small burst of starting fluid into the air intake... see if the bike fires over but that stuff is crazy powerful so has to be a really short quick shot... if you haven't used it before, not sure if you should try... but i use as trouble shooting tool to rule out fuel as the issue and see if there is spark.

 

Actually the fuel pump doesn't do much of anything until the engine is actually running. A way around this is to jumper the two wires together as shown in the manual for testing of the fuel pump. This will "trick" the bike into thinking it is running and the fuel pump will work.

Did you bench sync the carbs? That is an important step if the carbs have been split

 

Yes i did make sure to bench sync the carbs after putting them back together. and i tried spraying the starting fluid in the carbs and the bike runs for a good few seconds but than stops so its definitely a fuel problem. i am going to just order a new fuel pump as that seems to be the only thing that could cause it. maybe the pump starts and stops randomly i am not sure. but i am going to replace it anyways, worst case scenario i have a brand new fuel pump. But when the bike does start and rev it still has that very loud tinging noise, but i am going to guess i just need a valve adjustment or new shims as i know that can cause the tinging. I will update when i get the new pump. but i will continue to read and reply to this thread also in case anyone has anymore ideas or suggestions.