ok so i know you guys are tired of me posting threads of me not having a clue as to what grace (my 1995 cbr 600 f3) is doing but i am to the point of selling her for scrap. i cleaned the carbs so many times that they are tired of being cleaned. i changed the spark plugs so many times that i walk into autozone and they know what im there for. my vacuum lines are hooked up like they're supposed to be. my fuel pump works like its supposed to. ive said it in previous posts, but my bike acts like a diesel. it runs like sh*t until its warmed up... then it acts fine. responds to throttle input like its supposed to. today i tried to start it after letting it sit for a month (busy with work), and i had poured sta-bil in the gas tank so i know the gas is good... but damn it wouldnt hold an idle. it would half *** hold an idle of ab 750-800 rpms with full choke. any touch of the throttle and she would die instantly. if i left it with full choke with it idling 750-800 rpms, it would die after about 5-10 seconds. it definetly likes choke when being started. keep in mind i live in south-eastern north carolina on the coast, and today it was 75*F when i was trying to start it. my roommate *(who has 30+ years experience working and riding motorcycles) suggested a timing issue. i have never messed with the timing, but who knows what the previous owner has done. i know what yall are thinking now. after cleaning the carbs, how does she run? she runs like a damn top.... but why, after sitting for only a few weeks, will she not hold a damn idle or run at all??? i know that the first thought that comes to mind is "why does it run perfect after cleaning the carbs, but doesnt after a couple weeks" points to dirty jets... but damn... i doubt everyone out there that owns a F3 is cleaning their jets every couple weeks. she is verrrrrryyyy very picky. it was 75*F outside today and wouldnt even run without full-choke. yes i took every jet out and soaked in sea-foam, then cleaned every hole. yes i cleaned the idle jet with a very very small wire. im on the very edge of just selling her for parts. tonight i couldnt get her to go above 2K rpms. touch the throttle... and she dies. i tried adjusting the throttle screw by the petcock and nothing works. i got her to idle at about 800-900 rpms with full choke... and took the choke off and she died. tried again and tried touching the throttle... and she died again. the carbs CANT be dirty... and the spark plugs are brand damn new. i just cant come to the conclusion that the F3 is that damn picky. SO. i have the online manual for the F3 downloaded onto my computer. does timing ever get out of whack??? the exhaust smells rich as hell with gasoline. the vacuum/intake lines are hooked like they're supposed to be via the honda diagram. the coil packs are within tolerance as far as ohms (i checked with voltmeter). would timing gradually be outside of tolerance over time? or is it locked in, always the same? i am really, really frustrated with this bike. it has always required choke to start it; regardless of air temp. it was 90-95*F during the summer and still required choke to start it and get it warm. the only thing the bike has done to it is a straight-through no name muffler. i doubt that mod would affect it dramitically. i just dont understand why i cant go a month without starting it, and it not starting at all. my boss has a kawi zx-9 that had sit for 3 years and fired up on the first try. why do i have such bad luck / troubles? my fuel was stored with sta-bil since the last cleansing. are the jets on the F3 that damn picky? or do i have an ignition issue on my plate? sorry for the long rant but damnit if i cant figure this one out.

yes brand new spark plugs, yes brand damn new cleansing of the carb jets, yes the vacuum lines are hooked up properly, yes there is gasoline in the tank, yes gasoline is getting to the float bowls, yes the petcock is set to the proper posistion, yes regulator-rectifier is in fine working condition, yes brand new battery with plenty of juice, yes the bowl floats are free and clear for operation, yes the gasoline looked/smelled fine.

i thought for a minute that maybe i had a vacuum leak. so when she would hold an idle, i sprayed starter fluid on all 4 boots for the 4 carbs, looking for a change in the RPM (as if there was an intake leak) and the RPM's never changed.

im at the point that i have no more tricks up my sleeve... and dont know what else to do.

 

sounds as maybe there may be a choke problem if it wont idle up with full choke

 

I would suggest that you investigate the possibility of bad gas where you are. try filling up in a different area/different company's gas... also, you need to investigate the other side of the breathing cycle. do you have a major exhaust leak? cracked midpipe? as far as timing is concerned, if you pull off the timing cover and the valve cover, and rotate the timing gear until you get "in" and "ex" marks lined up in the appropriate places and then bounce that off the timing mark on the timing gear, that will tell you if your timing is off. also a valve adjusment is probably in order while you have the cover off, and its not that hard. i would also run a compression test cold and then warm it up and run another one to see if the rings are doing some crazy stuff at temperature.
something you have to remember is that these engines are just engines. they only need fuel, compression and a good spark to run. if you have all of that, it will run. before you give up, you need to investigate all of the possible suspects. one other thing that may be culprit is the fuel supply. you said your fuel pump is working, but is your filter clogged? there is a line pressure test you can do by filling a beaker with fuel from the fuel pump for a set amount of time and measuring the volumetric output of the fuel pump that way, i dont remeber the specifics off the top of my head, but it should be in the manual. good luck, and let me know what you come up with.

 

did you reset your pilot screws back to 1.5 turns out
and balance your carbs as best they can

then check (with the airbox off) to make sure both the a) choke cable and b) idle adjustment are working correctly.
perhaps reset them as best you can.

i dont know why it dies with throttle...
hmmm
sounds like something isnt acting the way it should in that department... im guessing something is causing it to get flooded.

it sounds to me like its gotta be something in that ballpark.

 

.........um, good job captain obvious.

 

Have you checked your secondary air solenoid stuff?

 

Where did the guy live that you purchased the bike from? When you was cleaning the carbs did you take the needle out? If you did and it had groves to adjust to with an e-clip. Then the carbs have an aftermarket jet kit installed.

On my race F3 when I installed the Factory Pro race jet kit. It requires more work and even drilling of the carbs has to be done. Most kits that people use you don't have to drill so don't worry about that. The main thing people get wrong is the main jet size. When I first jetted I used to big of a main jet. Which caused poor idle and hard to start. It also wanted to die at about 5k, bogged down. Had to crank to full thottle to keep it from dieing. The other clue is once its warmed up. Put a paper towel at the end of the muffler. Just burp the throttle a couple times. If you see black dots and gas smell then you are running to big of jets.

I've done allot of testing with my bike trying to get the most power out of it. F3 run better alittle lean on the fuel/air mixture. Plus even being off one step in jet size with the altitude makes a difference.

 

way to be a dick on a forum where people help each other.

i dont appreciate someone with 70 posts using them to insult a guy
who has 1200 used to help people.

 

@ spicy.... first, it was more of a joke than anything.... lighten up a little. we are hopefully all adults here. Secondly, while you are jacking your jaw about post counts, maybe you should think that some people only open their keyboards when they have useful input that no one else has previously stated. it pains me to see all of the nonsense posts that people make, and im not necessarily referring to yours, when answering peoples questions that have either previously been covered or worse yet are jut plain wrong. i am not going to automatically throw you into this group and i wont begin to try and judge your experience, but people on these forums do tend to just say whatever they think sounds good... which further confuses the person asking the question. and, in my opinion, that is the way that some members will jack up their post counts, but i dont care about that.
third, as a mechanic i would have to comment that i would hope that if you plan on offering your "expert" advice to someone, then you may want to take a minute and get all of your thoughts neatly organized, and fully explain the reasons that you are suggesting what it is that you are suggesting. that is all i was trying to convey in my own sarcastic way.
so, in the future, before you prejudge someone based completely on an abitrary number at the top right hand side of their post, stop and think that some of us spend more time troubleshooting and fixing bikes then shooting our mouths off on the internet. go back and read your original post, if you were a customer at a service department, would that have made a lot of sense?

P.S. i saw where you are from and this may not mean anything to you but if it does, i would have to say that i think it disgusting that SCAM NEWTON is still playing College Football.... and that would be some good ole fashioned ribbing between two SEC fans (I'm a GATOR)

 

lol first off, all allegations are off.
wanna start a war i am game football is football and i love it.

i try my best to help people.
ive made a ton of how-to's and walk through's in hopes of helping people...
im sure you might like a few of the things i did, especially the ones where i compare the new seats and such...

i like to think there are people who know a bunch about one thing, and less about another, which means he may be able to take his engine apart, but may know nothing when it comes to what plastics to buy...

im trying to help him fix his bike, ive been with him for quite some time, and im sure he knows me and how ive posted with my own problems.
im not really the most active person on this forum, but im sure people would back me when i say i post to help people and not to goof off.

now i may say some redundant things... but i thought i suggested 2 ideas that may have not been covered...
hell my problem was solved when i adjusted the pilot screws.