Hello. I own a 1987 CBR1000F. Recently I left the bike out in some bad weather (unexpected snowstorm). After sitting snow covered for about three days I went out to start it up and clean it off to bring into the garage. Bike started fine. idled fine, ran fine and was warming up nicely when all of a sudden it started bogging and losing revs and finally died.

My first impression was water in the gas. It only had about half a gallon in it at the time and that was a common problem with an old Interceptor I owned and had to park on the street back in the eighties. So I drained the tank and the carb float bowls on all 4 carbs, put fresh gas in the tank and sbegan to try and start it. Drained the battery in the process. Got a new charge on the battery and got back to cranking the starter. After some time at this, I went back to check the fuel system. Gas was flowing out of the tank and was visible in the filter before the fuel pump. I went to drain the carb floats to see if fuel was getting to the carbs and all four were dry. I was getting no prime, pulse or any indication that the fuel pump is functioning as it should, so I'm deducing that this is the problem.

Lack of a service manual brings me here to ask about any relays or switches on the '87 bikes that would be impeding current to the pump itself (fuses are good) everything appears normal

Anyone have this happen?

 

Did you check to see if you have power to the fuel pump? thats the next step I would take. If power is to the pump and the pump doesn't work, its more than likley a faulty pump.

Im not sure on that pump what the intervals for power to the pump are though. Some only have power supplied as its needed, some have constant power supply to the pump with a pressure switch that shuts it off.

You may also want to try and use a set of jumper wires to the pump and see if the pump works that way. If it doesnt, then there is surely an issue with the pump.

wish I could be more help, but Im not too familiar with that model and its electronics. I would however think there is a fuel pump relay somewhere along the line that should be checked as well.

 

Still scrounging for some wire to jump my fuel pump.

What I do know.

If I apply a circuit tester to the plug from the harness to the pump I don't get current when the key is on, but I do when I push the starter button

 

Hi Wooferdog, welcome to the forum.

You can download a workshop manual from here :-

https://cbrforum.com/forum/workshop-manuals-85/

Might be a help and is a nice to have anyhoo.

I think some guys run without a fuel pump and just rely on gravity? Maybe you could bypass it altogether just to get it going

 

I have an '87 and had same issue. Bypass fuel pump.

 

Yeah, I don't think I'd keep the fuel pump either. Just another component to fail on the road.
And considering that only the 87/88 have pumps anyway.....

So neal, did you install a vac operated petcock? I assume it doesn't have one in addition to the pump. Not sure about piping it into the vac system, either. Never worked on an 87/88.

 

Cutting the pump out of the circuit is OK
UNLESS you intend to use all the power the bike has, for extended periods,
THEN, the bike will run too lean, and you may have a major malfunction......
Happened to a mate of mine with an 88, cooked a piston and a couple of valves as I recall.

 

+1 for everything already mentioned.

One more thing however, if water is in the petcock and froze, you would not have flow. Bypass the pump and blow back into the tank. You should here it gurgle.

 

I did not install a vac operated petcock. I did the bypass on my spare bike only in an attempt to get it running.

 

Ok. Thanks to everyone for your input.

I bypassed the fuel pump and the bike WANTS to start. I do know that is what the problem is. I'm very reluctant to run it that way though.