I just bought a 98 CBR 600 F3 last week and have had no problems with it at all until today. I have been riding this bike all week long 200+ miles with no problems then, today, I get random hesitation and cutting out in the engine.

I started it, rode about 3-4 miles, then I got the first spitting and sputtering. It died on me, I restarted it no problem, and then I went on my way.... Another 3-4 miles down the road the same exact thing happens. I limp it home, let it idle in the drive way for a while with no hesistations or problems what-so-ever. I shut it off, let it sit for 10 minutes or so then went on another test ride. Got 15-25 miles away and it started again! All-in-all in my 35ish mile trip it started it spitting and sputtering 3 times, twice I was able to keep it running long enough for it to come out of it. The two times when it didn't die on me I just held the rpm's at roughly 5K and within a mile or two it came out of it and was running like new...

Background info - Bike has 21K miles, new oil change, caseys gas 89 octane, the guy I got it from said it is a newly rebuilt engine with ceramic pistons, cams, and stage 3 jet kit.....but who knows....

Any help would be appreciated,
Thanks,
Cam

 

Cheap/bad fuel?

 

maybe it's the idle speed that needs to be adjusted?

if the jet kit is new, maybe its not getting enough air, dirty air filter?

 

I think it was bad gas. I added octane booster and seafoam and it helped some, then put almost 2 gallons of 93 octane in and it is almost gone now. If the problem persists I will be back . Thanks fellas.

 

ive been having the same problems only mine doesnt go away unless i let the bike sit for a few weeks and then it just comes back in 100 miles. I just cleaned my carbs and found that my slow jet on cylinders 1, 2, and 3 were clogged. but now that i have everything back together im trying to start it up and its turning over but not starting... im about to go replace the spark plugs in a couple hours see if that fixes anything. let me know if you have any ideas for me.

 

Well I took the bike for about a 3 hour haul the other day. It was acting up BAD after 15 miles or so and I had to pull off the road because it died while I was riding. I pulled off, it had some trouble starting, then started and ran like a champ for 100+ miles then started it again. Now everytime I start the bike it randomly runs like that with hesitation and spitting and sputtering.

Interesting fact here though. It started doing it again going down the highway and I buried the choke, and it actually ran better! So I am thinking 1 or more carbs are messed up. Whether it be a choke issue or fuel I will probably take it somewhere to get them rebuilt.

Another thing I have noticed is that the bike runs fine throughout first and second. Say it just starts doing it and I come up to a stoplight it will idle fine and first and most of the time second runs fine...then at higher speeds and gears it starts its crap again.

IDK....I am new on working on bikes and don't know where to start really, plus I don't want to screw something up and not even be able to ride it to the repair shop...

Idk..Any help is appreciated,
Thanks

 

mine is doing it in at least gears 1 2 and 3 because i wasnt able to get any higher. im guessing it might be my throttle position sensor now... i cleaned my carbs and put new feul in and it sounds good but it still sputters

 

YAY! it was my throttle position sensor! i just unplugged it and it works, just a little slower than usual.

 

OK a little update on this thread. I tried unplugging the TPS but that didn't help anything. As of now I am on my second half of a bottle of seafoam and that hasn't helped much so tomorrow I am going to tear into the carbs and see if I can find out where the problems is.

The bike runs fine from idle to first and second but at the top of second it starts cutting out. 3rd + 4th are extremely choppy and 5th and 6th may as well not even be there.

 

I just read on another forum about a similar problem. His turned out to be a clogged fuel strainer where rust and other material had gotten into the tank.