Can you pull your new plugs out and take a photo of both new and old, then we can see what is going on inside of your engine. and yea I would definitely sync your carbs whenever you take them off or service them. I think you can rent the gauges from an auto parts store... But don't quote me on that.

 

Thanks again... I will definitely sync the carbs if I can ever get this thing started again... feeling a bit defeated at this point.

I'll see if I can pull the new plugs out tonight and snap some pics. I'm also wondering if maybe I kinked a hose or something installing the new plugs. It just seems so strange that all seemed well, and then it died. It was very tight in there trying to work behind the radiator... lots of hoses and wires getting in the way as I was working. Is it easier to pull the plugs with the airbox removed?

 

Much easier! Leave the Radiator attached and remove the airbox; as long as your working in a clean area, running the bike without the filter will be ok just don't do it all the time. And be careful not to drop anything in the carbs!

 

As requested, see below for photos of the new plugs and old plugs. When I re-installed the new plugs, the bike sounded like it was going to start, then it backfired, and that was it. I played around with it for a little while. I noticed that if I crank it with the choke on for a few seconds... and then follow that with cranking it with the choke off but throttle wide open, I get a few sputters like it wants to start. Does this mean anything?

Oh, and getting to the plugs with the airbox removed was MUCH easier... thanks for that. I have no idea why the owners manual gives instructions to move the radiator.

New plugs (in order of cylinder) Note, cylinder 4 already has some carbon on it...



Old plugs (random order)...

 

To me, maybe someone else can chime in as well, it looks like your running a bit rich. Still should sync those carbs and when you do get the bike running make sure your idle is sett correctly. Actually What is your idle set too? Maybe your pilot jets are not adjusted correctly. What does your air filter look like is it OEM or Aftermarket, what kind of exhaust do you have? Do you have the factory service manual?

 

Idle was running around 1,300 after I cleaned the carbs. I didn't touch the pilot jets when I cleaned the carbs (maybe I need to, but the repair manual mentions a specific tool for this). I pulled the main jet, needle jet holder, and slow jet. Air filter looks decent... OEM original (only 5K miles on the bike). The exhaust is a Yoshimura slip-on. I have a downloaded copy of the Service Manual.

I did get the bike running this morning before I left for work using the choke, no-choke/open throttle I mentioned in my previous post. It ran poorly, and I had to keep on the throttle to keep it going. One thing I noticed in the Service Manual... it states firing order as 1-2-4-3. I have the ignition coil wires arranged 1-2-3-4... did I mess that up? The 4th wire is longer than the 3rd, which leads me to believe it is supposed to be far-right. The only other thing I can think of is that I don't think I had the plugs torqued enough the first time around. I did the 1/2 turn past seating that the Owners Manual called for. This time (with the airbox out) I was able to get a torque wrench in there to torque to the 9lbf-ft the Service Manual calls for.

 

Just read the thread and my current suggestions are

1. Check the FLOAT needle valves. If they are leaking the engine will only use enough fuel at higher revs to stay running. At tickover it will flood quickly.
Listen very carefully after the bike has stalled - can you hear a hissing/sizzling sound ?

2. Check the diaphagms carefully for splits or pin holes - if there are any it will mess up the rising of the carb pistons and make the idle to mid / top transition messy.

Also - the ignition wire labels have nothing to do with firing order - they should be on the correct labeled plug position.

EG - put the wires as labeled on to 1,2,3,4. The firing order will be 1,2,4,3

AND - are you doing your testing without the airbox ? - these bikes run like crap without the airbox on properly.

 

"I have a downloaded copy of the Service Manual."
I know it's a little off topic, however I have been looking for a downloaded copy of the service manual and the best I can come up with was one in Portuguese not very helpful. DJA do you think you can send one my way please or anyone who has one for that matter would be greatly appreciated. as for your bikes situationI'm sorry to read that it has progressed into a situationthat only highlights difficult nature of having a carborated bike. I for one was very fortunate that removing my fuel pump was the cause of mybikes irregular running condition.

 

Dean0 - Thanks for chiming in! I'll pull the carbs again and check the items you asked me to check. And, thanks for clarifying on the firing order... that's what I thought, but when I saw new plug #3 looking cleaner than all other, and new plug #4 looking the worst (they only have 10 minutes of run time on them), I thought my issue might be pointing to those cylinders. And, I have done all testing with the airbox installed.

ErnsterO - I Googled "CBR F4 Service Manual", and it was the 2nd result... here's the link...
Motorcycle Honda CBR600F4 Repair Manual Download

 

thanks very much for the linkI've searched that website before from all of my home computers and it never popped up only a Portuguese one can't believe it was that simple. Wish you the best of luck on resolving your bikes issue.