Hello there,
I am having issues with my CBR F3's fuel system. Last week bike stopped on highway due to fuel pump failure. I got a new pump but the problem remained. Seems like the pump stops pumping gas and the bike just rans out of fuel. Checked relay, pump, some circuits and other stuff. Dont know for sure what is wrong. I dont have much time. My track days is due next Monday.

So, my question is. Can I do my track day without the pump on my bike? I plan on just buying a fuel hose line and put it directly between gas tank and carbs. I know I ll have issues on higher speeds. But still its better to run slower than just loose my track day. I won't be able to get new relay (if it is relay that causes the problem) so soon.
If you have any other thoughts of what else I could test I would appreciate it. Also If you happen to have cut off fuell relay I ll be glad to buy it.
Thanks.

 

Dumb question, but it's not addressed: Did you check the fuses, and your electrical connections? Those are two common failures, and quick fixes.

 

Its not an easy fix. And I dont think its a dumb question at all. If you dont know the subject please do not say that. Yes, I checked a lot of stuff. And right now I am planning on changing relay. I cant get one so soon. So my only option not to loos my track day is bypass the pump. Or may be you have a spare relay???

 

I'm not sure what you're getting at with that, so I'll assume it was well-intentioned. I understand that you're frustrated with your bike breaking only days before your (expensive) track day.

All too often, you see very intelligent, experienced people who jump right to 2nd-tier troubleshooting steps, because they're so used to managing more difficult issues, only to find that it was some basic scenario (such as a blown fuse) that simply slipped their minds while contemplating the depth of the problem.

If you think your relay is the problem, why are you talking about bypassing the entire pump subsystem? You could run a wire from the power source straight to the pump, thus bypassing only the relay. If the pump then works, you know its your relay. If not, you know its the pump, and you saved the ~$80 for a part you don't need. If the pump does work after bypassing the relay, head to Radio Shack and get yourself a toggle switch, and wire it all up to make your own "manual" relay. You'll have to flip it on your own, but at least you'll get pump functionality, and get more out of your day at the track then having to just deal with low speeds on a "gravity" feed.

 

As proof of concept, here's a thread with someone who did exactly what I reccomended, and claimed everything works fine like that:

https://cbrforum.com/forum/900-modifications-44/need-tech-nerd-experienced-mechanic-please-94906/

 

Thanks. Yes, I see your point. I ve read all that stuff. I tried bypassing relay, i tried running without the pump, i tested the harness. I went for a 30 miles ride and the bike was perfect. The pump seems to be working and relay seems to be fine for now. Thats what is confusing. If its just relay or pump, its easy. But if its smth. else, like CDI box or wire harness, it can be a hassle. The bike runs fine for now. But who knows if she wont let me down later...cause she did before. Yes, she runs...but then oversudden I am stuck on highway 60 miles from home. Bypassing the relay can solve the problem for now. But it can overflow the carbs in future. So the question is not only about saving my track day but about that issue in general.

 

Yes you can go to the track w/o the fuel pump.

Run your fuel line straight from the petcock to the carbs.

If there is a long straight at the track you're attending (1/2 mile or longer) just keep the tank 1/2 full at all times.

Ask me how I learned this