| Author |
Message |
    
Reno3d
| | Posted on Sunday, September 16, 2007 - 02:34 pm: | 
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So my S3T lunges unpredictably in first gear. It's a strong enough lunge to make you feel like if you aren't paying attention you could lose your balance. Things I can predict;
1. Easy to Moderate throttle.
2. Usually will lunge 2x ( 1st/rrrrrrr-L-r-L-rrrrrr/2nd/rrrrrrrrr/3rd/rrrrrr ( using L for lunge. )
3. The lunges happen in quick succession, and there doesn't appear to be any warning or sign it will happen.
4. Doesn't happen all the time.
5. Hot vs Cool doesn't seem to matter. This can happen 1 minute into a ride or 20 minutes later.
6. Seems more likely to happen if I've been waiting for a light on a hill than flat.
It's a little disconcerting as this doesn't happen predictably enough to take it to someone to get the problem identified and fixed. The last 2 times I've taken it to a dealer they couldn't get it to happen for them. At first I believed it was only on heavy throttle when this happened, but after the second time I've gotten the bike back I can verify that easy-medium throttle will cause it to happen.
The mechanics (both from Buell dealers) have been all over the clutch, and I've been told the belt is just fine. In a last ditch effort I've been running stabil with the gas but after 5 tankfuls this hasn't seemed to help.
At this point I'm open to any suggestions, but I need to admit that while I'm not a bad do-it-yourselfer, I'm not especially mechanically inclined.
Thanks for any input,
-Reno3D |
Sparky
| | Posted on Monday, September 17, 2007 - 11:38 am: |
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Lunge is defined as a thrust or push. Would you describe your lunge as a miss, like the engine misses a beat here and there or is it more like the engine drive becomes momentarily disengaged, causing rpms to pick up but not the bike gaining speed, or is it more like it seems to pick up a little momentary extra push?
The next time it happens, watch the tach. It's connected to the ignition power to the coil. Try to determine if the needle drops to zero suddenly or picks up a few rpms when it lunges. That would indicate either a discontinuity in the ignition signal to the coil or ???
Stabil is meant primarily to keep fuel from decomposing when not using the engine for periods of time. It's not exactly a fuel conditioner, I think. |
Reno3d
| | Posted on Monday, September 17, 2007 - 10:53 pm: |
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Sparky,
It doesn't feel like the rpm's pick up. It feels more like a split second void, then "Bang". It's hard and sudden enough to not describe it as a push. It could be a discontinuity ( it certainly feels right ), but only in first gear?
I'll try and watch the tach, though I'm usually looking ahead not down. 8)
Thanks for the ideas. |
Newbuellertoo
| | Posted on Tuesday, September 18, 2007 - 08:12 pm: |
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Sparky,
Could either of the issues you describe also be responsible for "Popping" and momentary engine die out? As with Reno3d Hot / Cold, In town, after a highway ride, doesn't seem to matter. But occasionally , blipping the throttle coming up to a stop, waiting to leave from a light, or downshifting, it will pop and die for a second. It has actually only died completely once, but started right back up.
I've only had the bike three weeks and never owned anything with a Harley engine before so I'm not even sure what engine noises are normal yet.It's been 20 years since I even owned a Japanese bike.
Thanks for any advice you might have. |
Reno3d
| | Posted on Tuesday, September 18, 2007 - 10:29 pm: |
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So today on the way into work, I managed to get it to happen 2x. On the second instance I managed to look down in time and the tach looked fine. Paying more attention to how it behaves I'd describe it as more mechanical feeling than a brief electrical discontinuity. However I could be wrong. 8)
Oh and yes, stabil isn't really a dedicated fuel conditioner but the label stated it helped clean the carb and remove water so I thought I'd give it a try. If you have a better product to try I'm game. |
T_edinger
| | Posted on Tuesday, September 18, 2007 - 10:51 pm: |
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My 07 12Scg does the same thing Newbuellertoo describes. I took it to the dealer Saturday for the 1K service, and the service tech (that had to ask what model it was) said it was due to the way I was starting the bike. He said I'm giving it gas too soon after starting and the TPS is changing. I really can't wait to take it back to them in another week to tell him he was full of s#*t. |
Blake
| | Posted on Tuesday, September 18, 2007 - 11:38 pm: |
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Have you recently upgraded to the new belt, the one that was released with the Ulysses? If so, you may need to increase your belt tension through adjustment of the rear axle wrt swingarm. The new belt is apparently a bit stretchier and can jump a tooth more readily when loose and if accelerating aggressively in 1st gear.
But if the problem is manifesting even under low throttle, then it is more likely that your transmission is the culprit, most likely the engagement dogs for 1st gear are worn and occasionally momentarily disengaging then re-engaging. |
Naustin
| | Posted on Wednesday, September 19, 2007 - 11:07 am: |
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Intake seals?
Seriously... Sounds like lean surge to the point it is missing... Read my profile to see if it sounds similar at all to the problems I was having last year...
Nick |
Reno3d
| | Posted on Thursday, September 20, 2007 - 11:23 pm: |
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So I tried a different fuel cleaner ( chevy techron or some such ), and almost thought I'd got it. Unfortunately, it happened again yesterday coming home. Its almost like I lose power for a brief sec, then it comes in stronger. I've been trying to pay more attention to the feel. 8)
So motor is still spinning, but when this happens it almost feels like the engine gets "stuck" for brief second, and then comes back in at a higher throttle than I'd been at before it gets stuck.
Naustin, I had an issue with the intake seals at about 18k. Had that addresses a while ago. This feels different.
Blake, the last dealer I saw about this went over the clutch. Are the engagement dogs somewhere else they might not have checked? Oh and FYI its still stock, although I think the spark plug wires are now some "screaming eagle" wires instead. That was done during the last check about 3 months ago.
Thanks for all the input. I'll try and keep analyzing what is going on. Other than this issue, the bike runs great. |
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1997 S3T intermittent/unpredictable lunging in first gear