Qu1ck
08-09-2007, 10:26 PM
Background: Bought my 1998 Honda CBR600 F3 in October 2005. Had local Honda dealer give it a tune up that 1st month in response to problems starting it. I’m not mechanically inclined so for upkeep I keep it keep it clean and waxed, with proper oil changes and chain lubrication. I put over 4000 problem-free miles on her last year before storing her for the winter with a proper dose of Sta-Bil in her tank.
Problem: Although it runs, shifts, sounds and responds fine during short (less than 6 mi) trips around town -- on longer rides after a while in 5th gear at highway speeds the engine will all of a sudden start to run rough (become noticeably noisier, sputter and hesitate) as engine RPMs and speed drop even while I’m opening up the throttle in an attempt to maintain speed; but to no avail. Then, as I pull over and downshift to 3rd or 2nd gear I’ve sometimes gotten near-normal throttle response and have limped home at 35-45 mph. This happened to me on my first ride this spring, then not at all on the next handful of longer rides. Recently it has happened on each of my last 4 longer rides at highway speeds. Yesterday on a new tank of gas the engine actually stalled on me as I coasted to a stop on the shoulder. I let it sit a minute or 2. Then it didn’t re-start until my 3rd attempt when I gave it full choke. Then the engine continued to ride rough and noisier during my 12 mile trip back home in 3rd or 4th gear although revving in neutral at stop lights seemed nominal from the standpoint of engine noise.
Can’t figure out why the problem always manifests itself when I’ve been at highway speeds for a good while – except for the fact that I do spend more time in 5th gear than any other gear during my usual rural fun rides. I’m stumped and fear major repair costs involved with a lot of trial and error efforts to find the real culprit.
Do any of y’all have any theories that match my observables? The problem seems to be getting worse. Thanx!
Problem: Although it runs, shifts, sounds and responds fine during short (less than 6 mi) trips around town -- on longer rides after a while in 5th gear at highway speeds the engine will all of a sudden start to run rough (become noticeably noisier, sputter and hesitate) as engine RPMs and speed drop even while I’m opening up the throttle in an attempt to maintain speed; but to no avail. Then, as I pull over and downshift to 3rd or 2nd gear I’ve sometimes gotten near-normal throttle response and have limped home at 35-45 mph. This happened to me on my first ride this spring, then not at all on the next handful of longer rides. Recently it has happened on each of my last 4 longer rides at highway speeds. Yesterday on a new tank of gas the engine actually stalled on me as I coasted to a stop on the shoulder. I let it sit a minute or 2. Then it didn’t re-start until my 3rd attempt when I gave it full choke. Then the engine continued to ride rough and noisier during my 12 mile trip back home in 3rd or 4th gear although revving in neutral at stop lights seemed nominal from the standpoint of engine noise.
Can’t figure out why the problem always manifests itself when I’ve been at highway speeds for a good while – except for the fact that I do spend more time in 5th gear than any other gear during my usual rural fun rides. I’m stumped and fear major repair costs involved with a lot of trial and error efforts to find the real culprit.
Do any of y’all have any theories that match my observables? The problem seems to be getting worse. Thanx!