Hi,
I am a new member, but I have been following this forum for general advise on maintenance and this is a fantastic forum with lots of stuff on all CBRs.I have a problem with the bike and need advise hoping tne 'experts' here can give me some pointers.I'd be descriptive so would be a long post, please bear with me
My 2002 CBR600f FI model seems to have developed a startup and sputtering problem. It goes back to 2-3 months ago when I had to change the CCT on it as it was rattling like a pig and then later a new air filter. With the new CCT the bike was back to normal but I started noticing that the revs don't quite climb to 3000 rpm an stay there for a while at startup to help it warm up.It was a bit erratic and would briefly climb to 2500 or so but would come down much faster to the idle rpm where as before the CCT job, it used to climb to 3000rpm and then gradually come down to an idle of 1300-1400 rpm.I said erratic as some days it'd climb close to 3000 whereas most days it won't.Also the idle frequency went down as well to close to 100.May be in the process of lifting the tank, airbox and throttle bodies fo access to the CCT I ended up disturbing something but not quite sure what. I didn't fuss too much about it as the bike still started on the button and the idle frequency was sorted by adjusting the idle rpm adjuster.The startup rpm got a bit more erratic when I pulled the tank to install the air filter-it's a BMC.
But this weekend I had the stupid(in hindsight) idea of installing O rings to seal the air box and throttle bodies along with ythe front pad change I had to do. I had noticed the bike didn't have these when I opened it up for CCT installation and the honda parts diagram shows it should have one, so I thought would order and install to prevent any leaks. After sealing the airbox with the seals and applying some silicone sealant on the outside of the box to seal the snorkels as well(had taken this out for the CCT installation), I put it all back together and tried to fire the bike up. It started on the button but would sputter and stutter even when given a few twists of the throttle so I turned off and tried again. But it won't start at all-the fule pump would prime like normal, the starter would engage and the bike would try cranking, stutter a bit but would not start(after a few attempts it won't even stutter only fule pump priming and starter crank would be heard)
I checked all the tubes and hoses and everything looked ok. I tried to think of all the things which could have gone wrong-
1)While pulling the tank up and pivoting it to rest on the seat area, the overflow and the breather pipes had come off, so I reconnected them also allowing air into the tank by opening the fuel lid.
2)While installing the O rings on the throttle bodies, I squeezed them into the bottom of the airbox by just lifting it a little without disconnecting the map sensor and other plugs or vaccum hoses going into the box. But the FI light would go off upon startup as normal, so I think they are fine as well.
Anyways, after trying multiple times I left it overnight and sought the help of google. It looked to be a flooding problem caused by multiple failed attempts to star. So the next day I pulled the throttle all the way in and tried starting on a WOT.It fired to life but obviously won't stay there so I kept the revs up by giving it lots of throttle and when it got warm it settled down.I rode around and it was fine yesterday except a few jerks at low rpms(say at idle and 2000 wth the throttle almost closed) which I noticed while pulling into a car park. The bike never jerked before at any rpms and there surely was something wrong, but higher rpms it was all fine.IT was fine all day with the exception of the revs only reaching to 2000 upon startup and then come down to between 1000-1200 or so and then gradually going up to idle of 1500 upon warmup.It didn't cutoff once though in the 5-6 short rides I did to run errands.
But today morning when I pressed the starter it came up in the first attempt but would again momentarily touch 2000 and then come down to around 1000.Only this time it died as I decided to not give it any throttle to observe what happens. But this time When I tried the WOT method, it didn't work as well. So I am stuck now. It looks like the autochoke is not working, may be something wrong with the wax unit? What could have resulted in this? Please note as I wrote above, I fiddled with the idle adjuster a lot when I first noticed the autochoke problem after the CCT job and then again a bit yesterday when I was trying to bring it up.
I am sure the bike would again startup if I give it some time, but I need to fix it up for good. Any help/suggestions would be most welcome.

 

Would suggest first off to have a look at your Fuel Pressure Regulator, you will finda test on you tube, to see if its ok.

 

Thanks CaBaRet.
I'd have a look at the FPR when I open it up(again!) this weekend. For now I have gotten around the problem and at least can start it up and ride. So after it refused to start I let it be for a day as the engine was flooded and let the plugs dry a bit. The next day I tried the WOT method and it worked. The fast idle mechanism doesn't work though so the revs would fall immediateley after startup and bike would die down.So I keep on giving it throttle, maintaining the revs at 3k, basically do what the fast idle unit should do , and let it warm to 70-80C, takes a blo*dy long time in the -7C temp here now and I am sure the neighbours are not happy.Once it's warm it manages to hold the revs easily and is eminently rideable with the exception of some hiccups and choppiness at low revs,which tells me the FPR may be at fault,as it used to be super smooth throughout.
One thing I noticed though is that when I fired it up with the WOT method the exhaust note is very different and nothing like the inline 4 humm, but more like a twin or single. It keeps sounding like that and if I give it more throttle, the revs don't climb like they should.In the process of warming up I notice the rev needle jerking a bit and the exhaust note then changes to the usual inline 4 note and then it's all hunky dory from there on. Could it be that only some cylinders are firing up? I have no way of verifying that on initial startup as I need to hold the throttle and can't check the pipes by spraying water or touching!
So from what I understand till now after reading up on the net and consulting Haynes is either of these or a combination of these are a problem-

1)The fast idle wax unit is faulty as the problem is startup
2)The starter valves are out of sync or faulty
3)Some injector is loose or faulty
4)FPR is faulty
5)Bad spark plugs but that may be a manifestation rather than cause as bike is fine once it warms up and rides normal.
The can keeps on smelling of gas especially on startup and is not hot at all to touch-granted the current cold snap doesn't help but I'd expect it to be at least warm so I am sure the fault above
As the problem only started after I fiddled with the throttle body assembly(first to install the CCT and then later for installing the O rings)
I have now ordered spark plug wrench and other bits, hopefully they arrive by this weekend for me to have a look at the plugs.I think may be something has come loose?
Again, any pointers welcome.

 

The spark plugs once out can tell you a lot about whats going on in the engine, could be anything yet , so when those plugs come out should be a good pointer.

 

My F4i was detonating and spluttering when I got it, the owner had been running 91 ron cat's **** in it, I drained the tank and put 98 ron fuel in it and it ran fine straight away and continues to get better

 

So ordered new plugs on eBay and in they went. The ones which came out were all black and sooty which basically confirmed what I suspected from the smell of gas on startup and in exhaust plus the low mileage(not even 100 miles before reserve bar flashing on speedo-and this is just commuting at 5000rpm and small errands)- Super rich mixture. The amount of soot was more or less same over all 4 but the leftmost had a bit of pitting and some white stuff but that was in the area which does not see the inside of the cylinder so not sure what to make of it.
I was hoping that the problems would magically go away once new plugs go in but nope,no change whatsoever.Although there has been some very minor improvement at lower end.It is slightly less snatchy at low revs now but only just. Apart from that it still is weak at startup and revs only shoot up to 2000rpm and the almost immediately fall down to 1200 something gradually settling at idle of 1400
Btw this was the first time I changed plugs -used NGK IMRC-9H - and was a bit scared using the torque wrench for the 12nm rating as that sits at barely 3nm above the lower limit of my wrench.But it went all fine and thank God for that- every time I open the bike up I fear for something else falling apart. This time it was the right air duct cover screw setting which sits on the front cowl. I lost it somehow so need to figure out something.
Back to the main issue, I have ordered a fuel pressure regulator from the US from a site called partzilla.Not sure anyone have used them in the UK but the parts are dirt cheap. The local dealer and pretty much every other dealer/internet listed it for approx £140. Partzilla had it for $50 something. So that ,the o rings and the two nuts cost me the equivalent of £59 including international shipping. Add may be 20℅ more for vat during collection at the post office and it's still roughly half of the price in UK. A few months ago when the £ was not this weak would have been even cheaper.

 

If your doing Spark plugs, never use a torque wrench on them, just pinch them up tight by hand, Hopefully the FPR could get a steady right flow, good price for the part, hope it comes soon

 

Thanks, won't use the wrench the next time. Wouldn't there be a risk of gas seepage if not proper tight though?
Not too sure about the Fpr though. I had inspected it while changing the plugs and couldn't see any leakage or anything. The vaccum line going into it smelled of gas but no fuel dripped out of it when I primed the pump.
If this doesn't fix the problem then will have to look into the wax unit and the starter valves. Hoping it's not because the valves are out of spec.Don't want to open it all up for shim adjustment.

 

The trouble with plugs if you over tighten them is that they could snap off when undoing that becomes a real problem trying to get the broken plug out, just a good pinch up should suffice, the starter valves could do with a cleaning ,and that could probably be done while waiting for your FPR.

 

Feel plugs grasp, then quarter turn. Hand tight is too loose, they'll vibe out.