Hi all!

Just looking for some advice. I recent became the proud owner of a 2002 CBR 600 F4i and its not running as it should.

It will sometimes not start, turn on ignition, press start button and it make a big knock sound and fails to turn over. I then check the battery voltage and it’s showing 12.4. When I touch the multimeter leads to the terminals it will then allow the bike to turn over? After that, it will turn over no bother, unsure if this is related to the main problem. Very strange.

Then, when the bike starts, it will idle up to 2 - 3k revs from cold, and when it reaches temp, it will idle down to 900-1000 ish revs (seems low to me).

After riding the bike for a period of time, when I come to a stop at lights or junctions it will sometimes just die, only way to start it is to press start button and rev it up. It also has a strong petrol smell, indicating it may be running rich.

I’ve changed the plugs as cylinder 2 & 3 were fouled. After that it ran okay for a bit, but has unfortunately gone back to running bad.

I’m very much out of ideas, I’ve seen some posts about checking the FPR as they can go bad. I have done a check this evening and the FPR is piddling out of the feed side when the ignition is turned on. It’s not a big amount; but should the FPR push out fuel when the ignition turns on?

I am by no means a mechanic, and this is my first big bike. So looking for any advice as I would love to get it back to running order!

Any advice is very much appreciated!

cheers!

 

Quick update, I figured out the starter issue is probably caused by a dodgy pinion gear where the starter meets the engine.
It seems when I wheel the bike a little after it does the clunking noise, it will then start up no problem.
Will need to look at either lubricating it, or replacing it all together.

Still no luck with the running issues.

 

You've got multiple issues:

1. adjust your idle **** so engine idles at around 1200rpm

2. measure pressure in fuel-rail at idle and 3000rpm. If doesn't meet specs in manual, replace FP

3. check battery cables and cable from starter-solenoid to starter. Clamps may be loose and/or cables may be corroded internally

 

Thanks for your feedback, so I have checked the idle adjustment, it now sits around 1100 - 1300 rpm when idling after warming up.

I put it into a family friend who has a shop to see if they could narrow it down. They took out the throttle body, injectors, fuel rail + FPR and cleaned the whole lot.
After, it was tested and everything was working as it should fuel system wise and all was within spec.

Weirdly enough, when it was re-assembled, he took it for a ride, and it was running as it should for the first while, however, when taking it home, it was back to running like before - lumpy, under powered and stinking of fuel.
It was also noted that Cylinder 1 was cold while the rest were up to temp when he checked with a thermal gun. Unfortunately, they didn't have much more time to spend on it, so it is back to me.

I pulled the coils and plugs today, and sure enough plug in cylinder 1 was covered in fuel / black burnt oily residue.
The others were fine! No FI light came on at all, so unsure if a bad coil would trigger a code?

I then checked the coils, going by the Haynes manual, I checked the P Range resistance and the S Range resistance of each:

Manual Says Primary Range is: 1.1 - 1.5 ohms & Secondary Range is: 11.4 - 11.8 k-ohms

Coil 1 : P = 1.5 ohms S = 11.62 k-ohms
Coil 2 : P = 1.5 ohms S = 11.39 k-ohms
Coil 3 : P = 1.5 ohms S = 11.41 k-ohms
Coil 4 : P = 1.5 ohms S = 11.39 k-ohms

Now, these all come within spec, so I'm going to rule that out. (However, I have been told coils can sometimes malfunction under high-temp due to resistance changes if the coil is bad, so not sure what to make of that, can anyone confirm this?)
Battery connections and grounds all appear to be good, relays, lights all come on. Bike starts no problem - even with the sticky starter which I plan to fix - but it just isn't running right, definitely a miss-fire in Cylinder 1.
Trying to avoid taking it to a garage, as it can be quite expensive and would rather rule out as many things as possible before I have to go that route.

 

Stop replacing parts, you may be introducing additional errors into system. With old crispy wiring, just act of unplugging and re-plugging connector can damage wiring. Measure each and every part and all wiring connecting them.



Do more measurements. Somewhere, some place is number that's out-of-spec:

1. do compression test. Post numbers here

2. voltage to each coil, volts 1,2,3,4 = ??

3. resistance of coil trigger wire to each coil, ohms 1,2,3,4=???

4. resistance end-to-end of each plug wire, ohms 1,2,3,4=??

5. resistance of each plug itself, ohms 1,2,3,4=??

6. spark test: pull plug wires and plugs. put plug into wire and ground to block. Crank engine. Do you get bright blue spark?

6. voltage to each injector, volts 1,2,3,4 = ??

7. resistance of trigger wire between ECU and each injector, ohms 1,2,3,4=??

8. actual static flow-rate of each injector at 3-bar pressure, cc/min 1,2,3,4=???

9. squirt 2-3cc petrol into airbox. Wait 30-seconds, run bike. Does dead cylinder run now?

 

Okay, I’ll double check all the above tomorrow, and report back.

I’ve only replaced the plugs, but promise I’ll not replace any other part until I’ve completed the above.

I really appreciate the help!

 

Okay so managed to do somethings today.

Ordered compression tester, should be here this week.

checked plugs resistance, all are within spec.

1 = 4.9ko 2 = 5ko 3 = 4.9ko 4 = 4.9ko

tested all plugs for spark, all looked healthy and produced fat sparks.

What’s the best way to check coil voltage? Do they need to be plugged in to the harness then attempt to to start it with multi-meter attached?

I did the air box test, bike does start, but cylinders are not hot (checked down pipes) only cylinder 2 + 3 are firing. So looks like it’s 1 and 4 that are miss firing.

I went and checked codes on ECM, I got an error with 9 flashes. Which if my manual is correct, is a faulty IAT sensor. To make sure it wasn’t a previous code. I erased the codes, then fired the bike up. Let it run for a bit, then checked again, and the code returned. Would an IAT contribute to the issues I am facing? (Not going to change it until I have done the other tests)

I also found corrosion on a plug that is off the left hand side of the bike - big grey plug - like the one that connects the front nose code harness. This harness looks like it connects into everything near the center of the bike. Not sure what the name of the connection is, but has a Green plug near it.

I will get time this week to do the remaining checks that you have listed.

cheers.

 

To measure voltage at coil & injector connectors, unplug then all and measure each terminal:

 

Ok,

So I check all coil plugs as shown above, the voltages matched what was specified in the Haynes manual.

I did a compression test on each cylinder:

1: 163 psi
2: 165 psi
3: 165 psi
4: 163 psi

These numbers seem okay, and are within range within the Haynes manual.

I am not sure how to check static flow pressure, will I need a professional to do this, or can this be done at home?

I also checked the Fuel Pressure Regulator. The vacuum line has fuel in it, it leaks fuel when I turn the ignition on to prime the fuel. So looks like I have a faulty FPR. Could this be the source of my problems?

cheers!

 

Very well could be broken diaphragm in FPR.

Use vacuum-pump to pull some vacuum on FPR. Does it hold vacuum? or does it drop?
Similar to testing petcock diaphragm on carby bikes.