I need help!!

[stealth66]

Ok guys here's the thing. I need some help in getting my engine to idle and run right. I have a 93 FZR600 that doesn't want to idle or run evenly. It sounds like a miss or timing being off. It's power is weak and you can definitely feel it die at higher RPMs. I also have to keep the choke half on to keep it running.
I have done a bunch of things to try and fix the situation. They are as follows:
I have: Cleaned the carbs
Rejetted the carbs
New emulsion tubes
Compression is good (within range)
Valve clearance is good (within range)
New header
new fuel filter
pump checks out
ignition box is fine
New K&N air filters
Replaced plugs
Replaced ignition coils
Replaced VR
Replaced Battery, new terminals
i've even tried adjusting the carb idles with vacuum guages and they seem to be fine and have little efect
The idle set screws on each carb are at 3 turns out (and have tried adjusting)

Any ideas, pointers, any somewhat common problem that i might be missing, please please let me know. Any idea will be well appreciated. Thank you guys!!

[95FZR600]

are you running pods? That was the only way for my bike to run right. I was having similar problems and once I went with pod filters it ran strong at all rpm ranges. Something to think about.

[stealth66]

Thanks, Yeah i do have the pods. I did the YZF tank swap so i have to. Any other ideas?

[FizzNation]

I think you need to start tearing into the engine and seeing if any thing is out of place. Also check all your wiring. These FZR's are old and you could just easily have a couple corroded grounds. So check all the grounds and clean them. Another thing you can check is the fuel pump, your fuel pump could be weak. I would always have to leave the choke on a little bit for it to stay running and i could feel weakness at high rpms. but that was probably due to the rats nest that was in my air filter. My whole air filter was filled with shit.

I'm rebuilding the carbs right now so my bike should technically be up and running

[shredex]

have you tried to sync them?
my A/F screws are 1 and 1/4 turns out
i would turn them back into about 2 turns out, then sync the carbs...syncing them should solve the problem

[stealth66]

Thanks a lot guys! I have checked the compression, checked the valve clearance, boots, and wiring so no problems there but i will inspect again. I am currently trying to synch up the carbs. Its tough because its so off that i have to try and synch them with the choke on because it wont run without choke. I'll try backing the mixture screws in too but they're at the factory 3 turns out. I'm going to try to synch them again today. If i can get them close enough so that i can take off the choke, maybe i can get them dead on. If that doesn't work, i'll have to re-take apart the carbs and see if i missed anything. Any other ideas guys, please let me know. Thankis again.

[stealth66]

Thanks a lot guys! I have checked the compression, checked the valve clearance, boots, and wiring so no problems there but i will inspect again. I am currently trying to synch up the carbs. Its tough because its so off that i have to try and synch them with the choke on because it wont run without choke. I'll try backing the mixture screws in too but they're at the factory 3 turns out. I'm going to try to synch them again today. If i can get them close enough so that i can take off the choke, maybe i can get them dead on. If that doesn't work, i'll have to re-take apart the carbs and see if i missed anything. Any other ideas guys, please let me know. Thankis again.

[shredex]

turn the idle screw way up so it will run on idle without choke
clockwise to raise idle
counterclockwise to lower idle

[stealth66]

Good idea, thanks man. i'll try that this afternoon and see if i can't synch it better that way. At least that way maybe i can tell which carb may be clogged if any. Is there a way that i can check which cylinder is having the issue?

[shredex]

you can heat test each header and the coldest one will be your problem cylinder...id do the idle adjust first then sync...that is probably your only problem.
just run the bike on choke then SLOWLY starting closing the choke till it gets to the point that the idle is were it seems it should be at...if the choke is still engaged then you need to raise the idle up higher and keep closing the chock and raising the idle till the choke is completly closed and your idle seems right....then sync

[stealth66]

Sould i do this with the individual mixture screws or just raise the main idle scew up? I'm thinking, put the individual mixture scews in 2 turns (from 3), choke it, warm it up, slowly let the choke down as i increase the main idle screw then synch. And if for some strange reason, i get the carbs well balanced, i'll take the idle back down to normal and adjust the mixture scews depending on throttle response. Idoubt i'll get that far though.

[shredex]

just raise that main idle screw so its high enough to run without the choke.
your screws are 3 turns out which means its allowing more fuel into the carbs just like what happens when you have the choke open.
if the bike ran good before though and you havent changed or jetted differently since, and the screws were at 3 turns, then leave the screws alone....if not, put them at two turns, then raise the main idle

[stealth66]

Ok i just put the screws in one turn and raised the idle screw. I hooked up the vacuum gauges and they all seem pretty even which is strange but i did notice that when it starts to die out, the pressure is the same in all except cylinder one. The pressure seems to go back to almost zero until i reopen the choke. individual adjustment of the mixture screws does not seem to do anything.

[shredex]

that could only mean that the main jet in cylinder one is clogged.
id check that out

[stealth66]

I'm going to try and spray starter fluid while its running and see if that brings the #1 cylinder up. If so, somethings clogged. The main jets have just been replaced and its seeming like maybe the bowl is getting empty. Will the pilot jet cause the same thing? I really appreciate your help.