F3 Problems....

Tavish · 09-26-2006, 10:32 PM

Ok, as im sure ALL of you have long since forgotten me, ever since I crashed my 929 a few years back, I got an '04 636 and just kinda lost touch with all of you. SO! Here I am, back for a tech question, I remember coming to you guys for questions and helping other people with problems as well, so here goes nothing. We are having a problem with a friends CBR 600F3 , it idles and dead revs perfectly, but once put into gear, the low end is perfect, but on high end the bike bogs down and sputters completely underpowered. We have tried replacing the fuel pump, air/fuel filters, replacing jets, cleaning out the tank completely and making sure there is NO water in the lines. The problem hasn't changed at all, we've done everything but running a compression test on each cylinder, has anyone heard of this problem before or know of anyway to fix it?

BDA116 · 09-26-2006, 10:36 PM

The dual stage CAI system.
Have you fiddled with it? Removed it in any way?
Particularly the valve that sits behind the airbox?

SomeStrangeGuy · 09-26-2006, 11:12 PM

sounds stupid but, oe exhaust or aftermarket?

Tavish · 09-27-2006, 3:03 PM

OEM exhaust, and BDA im findin out about the CAI system, like I said, its my buddies bike so im not 100% sure about what he has done on his own to it, but that sounds logical

BDA116 · 09-27-2006, 3:17 PM

My F3 had similar symptoms twice. The first time was when I gutted all of the low speed air system (I thought all of which was not needed), and the bike lost all power and bucked over ~25-30 MPH. Had to remedy that by replacing a couple of the hoses and connecting them directly to each other, leaving the valve and all the other stuff out.
The second time the bike didn't react quite so violently, but it did lose power over ~30 MPH, and that was due to the fuel pump relay. The pump itself worked, but the lead to it out of the relay had no juice.
I did a trackside fix of wiring it direct to a different hot wire (i think the taillight wire), and never did replace the relay.
Not the best long-term solution, though.

Tavish · 09-28-2006, 8:01 PM

After checking over the CAI system, it seems fine, we don't think thats the problem, but still find ourselves dumbfounded to whats causing the loss of power and sputtering....anyone else have any ideas? I would think it has to have something to do with the gas, gas lines, pump, something.....we just don't know what

BDA116 · 10-05-2006, 4:38 PM

Like I said, it happened with My F3 twice. Once was the CAI system, once was the pump realy had gone bad. I'll bet it is one of the two.
If you took off the low-speed tubes and valve, that will cause those exact issues. If the valve has gone bad, same thing.
If your pump relay is bad, you will have no power at the pump. Easy to check.

ginkof · 10-14-2006, 4:12 AM

I purchased my bike with a problem like this. and this may sound like a very stupid thing to check, but replace the battery with the one in your bike and see if it goes away. My battery had some messed up internals and couldn't hold enough of a charge or something wierd at about 35-40mph.... I ended up giving up and taking it to the dealership and spent $200 to find out it was a battery...

Tavish · 10-14-2006, 11:35 AM

We fixed it, there was a selonoid(spelling) that went bad, we disconnected it and it seems to run fine now, eventually it will be replaced

goul · 02-27-2007, 8:13 PM

'am new here, and would like to ask something since you mentioned fuel pump here - do you think car fuel pump can sustain? I've just got a 1996 F3 recently and found out that the pump installed is not anymore original.
It's hard to say if it's ok since i don't ride her that much since. 'appreciate to get any insights. TIA!