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Stumbling 6th Gen...

10 posts Started 19 Aug 2008 Last recovered post 20 Aug 2008 Wayback Machine snapshot 10 Apr 2010

#1
Hey all. I was riding my '02 saturday evening at low speed through the city. I had noted to myself at one point, without looking at the tach, that the famous 4500rpm stumble had seemed to really be acting worse on that particular ride. But, that stumble which many of us know about doesnt bug me too much anymore, now that I know that its "normal" for an '02 and others. But, just after noticing this, I got to the next stop light and noticed the bike idling at an indicated 800 rpm's or so.....much too low. After keeping the idle up with the throttle and beginning to take off slowly again, it started to stumble and hesistate at other rpms as well, in almost the same way as the characteristic 4500 hesitation. Very light throttle, just barely accelerating, and mainly at lower rpms. It started acting up to the point where I was now making preparations to pull over and call for a ride, since I figured it would just keep getting worse and die out.

By this time I was now heading south out of OshKosh and getting onto country roads, so the speeds were higher. I didnt notice it nearly as much, although something still didnt feel quite right but i couldnt put my finger on what. Possibly the initial throttle response seemed a bit off, or I couldve just been evaluating everything too much at this point. I decided to just keep going to Fondulac, which would bring me down to city speeds again, and then i could evaluate it again. When there at a rest stop, i tried riding around slowly to induce the problem myself, and still i could get the bike to slightly run poorly and jerk upon very light throttle. I was kind of hoping an FI light would come on, or even just die out to make diagnosing easier. But, neither ever happened. I filled up with fresh fuel from Shell as I was down to about 1/4 tank, and I rode the remaining 50 miles home on the freeway, and everything seemed ok, although at higher speeds it hadnt been acting up as much.

I got back home here, and within a few blocks of here where i was down to city speeds again, i caught it stumble once quick and that was it. I havent had the chance to ride it since, but plan to soon.

Any ideas or other instances like this one?

And btw, this past winter I replaced the fuel tank due to last august's high side. while it was apart I replaced the fuel filter, and the pump was changed over from my last tank. Maintenance is totally up to date including fresh OEM plugs, newer air filter, starter valve sync a month ago, etc. The only thing that has been neglected is the valve adjustment. The bike currently has 40,500 miles. And the wiring harness recall had been performed in spring.
#3
Give it more air. Remove the snorkel on the A/F cover. It's reversable.
#4
Even though you have done the recall, check your stator and rectifier and make sure they are putting out the correct numbers.

Also, could it be a bad batch of gas (the bike, not you)?
#5
I had these exact same symptoms. I volt tested my battery and it was slightly low, so I brought my battery in for a test and it failed the load test. With a new battery, it seems to run great again....but I suspect there's something else going on (electrical) and probably a stator issue. I haven't checked it yet because I am lazy, but will be pretty soon. I would focus on electrical, not fuel.
#6
I have had the same issues with mine this year. Exact to the tee! It appears mine started after the recall work. I am too busy right now to look to deep into this right now though. There have been several times that I have come to a stop and the engine is loping along under 1000 rpms. When I try to blip the throttle the engine bogs down or stalls. I have tried the idle control but I don't think it is it as most times it idle's just fine at the correct RPM's

I guess I will start looking at the suggestions here to see if I can find the problem.

Cheers,
#7
My bike has been acting strange since I had the wiring harness recall done. (Not to mention the fact they still have not put the ABS harness in and I have been sans ABS all year.)
I have stumbles that I never had before and VTEC slams in much different, it's like hickup-bam-VTEC.
#8
Thanks for the replies so far...

Concerning the idle adjustment; I couldve adjusted it up back to spec, but I shouldnt have to. Idle adjustment should only be one of those things you only have to do once or twice in a bike's life. The adjustment wouldve just compensated for the cause of the low idle. And, the odd thing is that it started idling back at spec after awhile... Basically, it wouldve solved the low idle issue quickly, but im kinda interested in why the idle dropped that much to begin with.

I have thought about the bad gas thing. I dont think its too likely, but ill try and ride it this week yet with that fresh fuel in some more, but Im honestly not expecting that to help too much. but, i can just hope for the best I guess.

Im kind of thinking electrical too. These days, with most of the bike being effected by electrics either directly or indirectly, i think thats a good possibility. If its not a fuel issue, an electrical problem can make it a fuel issue on a bike like this.

But, keep your replies and ideas coming....
#9
oh, and also, the battery thing did cross my mind. ive volt tested it but not load tested it; yes, just a volt test only tells part of the story. I may look into that here first just so i know where i stand. I should also mention that earlier this year, I did replace the stator and RR due to the 3 pin regulator/stator connector melting. I wasnt sure where the exact problem lied at the time, and i needed it fixed fast, so i just threw a new stator and RR in, and got rid of the plastic connector and just hardwired them together. And no, I did not replace the battery at that point.
#10
Did just check the battery for the heck of it; its holding steady at about 13.2 volts after the bike's been off for awhile. I did use my automotive battery tester to test the battery that we use in the shop; the battery still has 211cca capacity (spec is 200 I believe).

Im going to ride it this evening and see how it is...
End of thread · 10 posts recovered Wayback Machine snapshot 10 Apr 2010