• There has been a recent cluster of spammers accessing BARFer accounts and posting spam. To safeguard your account, please consider changing your password. It would be even better to take the additional step of enabling 2 Factor Authentication (2FA) on your BARF account. Read more here.

F4 sputtering when hot

kneedragon2000

kneedragon2000

wait...wut?
Joined
Aug 11, 2003
Location
Livermore
Moto(s)
02 custom R1 streetfight// 08 Ninja 650
Name
Robin
does anyone know of a typically symptomatic issue with the F4 (2000) when they get older they sputter when hot?

I picked up a used (60k) F4 about 2 months ago. it runs well enough but I noticed two things.
1. when I try to reach redline it subtly lurches when it gets to the higher revs. it still pulls but it pulses a little in the power delivery
2. in the morning after I warm her up she comes off the line just fine. I dont rev her up and then slip the clutch much. I have the clutch completely engaged at around 1.5-2k and the motor pulls from there fine... in the morning. BUT when I am on my way home from work, especially yesterday it hiccups or almost stalls between 2 and 3k and I need to rev her way up to get it going.

is that a simple carb sync issue? idle jet?
something else?

any thoughts?
 
I think it might have to do with carbs. Maybe a good cleaning may do the trick. Sounds like pilots are clogged and maybe main jets are a bit small causing starvation a bit at the top end. But you are on track with the carb issue. Carb sync probably wouldn't hurt either.
 
yea
the other thing I noticed is it stops the issue for a light or two if I wind it up to the limiter (as Im moving) or off the freeway where I am 6.5k or so - almost like it cleans it out a bit. I do a LOT of low rev commuting... stupid fremont/niles canyon commute :(
I have a feeling it might be because of the low revs?
 
Possibly also I think those carbs and fuel system run off vacuum. Well at lower revs maybe you are not getting enough draw and something is clogged. Don't remember how the F4's system works exactly but I would suspect carb cleaning would do the trick.
 
do all the standard maintanence and itll run like a champ.

plugs
valve adjust
carb sync
fuel system cleaner

try the first and last ones i listed now as they are less work, but ull prob need the other 2 soon.
 
kneedragon2000 said:
does anyone know of a typically symptomatic issue with the F4 (2000) when they get older they sputter when hot?

I picked up a used (60k) F4 about 2 months ago. it runs well enough but I noticed two things.
1. when I try to reach redline it subtly lurches when it gets to the higher revs. it still pulls but it pulses a little in the power delivery
2. in the morning after I warm her up she comes off the line just fine. I dont rev her up and then slip the clutch much. I have the clutch completely engaged at around 1.5-2k and the motor pulls from there fine... in the morning. BUT when I am on my way home from work, especially yesterday it hiccups or almost stalls between 2 and 3k and I need to rev her way up to get it going.

is that a simple carb sync issue? idle jet?
something else?

any thoughts?
Click to expand...


Mine does the same thing. It only bcomes an issue when I am splitting and need to get off the line quick and my baby sputters...not often or bad enough but am curious what the answer is.
 
stangmx13 said:
do all the standard maintanence and itll run like a champ.

plugs
valve adjust
carb sync
fuel system cleaner

try the first and last ones i listed now as they are less work, but ull prob need the other 2 soon.
Click to expand...
agreed :thumbup
 
ok good. as long as mine isnt the only one. Im gunna try some fuel system cleaner first and go from there...
 
Kneedragon did you figure out/fix the problem? I have the same thing with my F4 - runs perfect at all times other than when it's hot in stop and go traffic, then the idle is rough and it sputters when pulling away.
 
not yet. havent had time to take it apart. I went to start it last week after letting it sit for a few days and it choked off and almost died about two houses away so I parked her and rushed to work in my car. I am going to see what the hell is up soon tho
 
kneedragon2000 said:
not yet. havent had time to take it apart. I went to start it last week after letting it sit for a few days and it choked off and almost died about two houses away so I parked her and rushed to work in my car. I am going to see what the hell is up soon tho
Click to expand...

Go to a local Kragens or Auto Zone and purchase some 'Sea Foam'. Sea Foam is in a white bottle with a red logo, should have about 16-20oz of fluid. This stuff works great. I had an FZR 400 that has not ran for 10-15 years. I did a clean one time, but not the best job, I ended running straight Sea Foam (no mixture with gas) and it cleaned the carbs very well. Don't worry about the smoke the exhaust gives out, just run 1/4 of the bottle and let it sit in the carbs for about 12 hours. This should fix your carb problems. Good luck

Sergio
 
well, I will try that for sure
I just tried to start it and it didnt even try....

I assume that it is still a fuel delivery problem so I will pull the carbs and tank and try to clean it out, but would like to avoid that if possible.
 
My F3 is having a similar problem. Took it for almost a 2 hour ride today and it got the hottest it's ever been. Temp guage was about 4/5 of the way up. I normally start off a 2k rpms just fine, but at that temperature it almost stalled and I had to feather the clutch to get it to go. I'll probably try some sea foam as well.
 
You must log in or register to reply here.
Back
Top