Hiccup in power delivery accelerating in 2nd. very troubling.

[zixaq]

Hey all, I need experts.

Sometimes (hard to repeat), when I'm accelerating hard in 2nd gear, there is an abrupt stop/start to power delivery that lasts less than half a second. The engine tone doesn't change much, so it seems like it has to be something in the transmission. How bad a thing am I looking at?


1. Engine sound doesn't change except possibly to speed up a little, but it's such a fast glitch that I'm not sure. Anyway, I don't think it's an engine, fueling or electrical problem, but I'll entertain ideas if you disagree.
2. Chain and sprockets still look good. They're fairly new (10k ish) and high quality and the chain tension is correct.
3. I'll be checking the clutch at the next oil change, although I don't know how the clutch could cause an abrupt transition only in one gear.
4. I cannot reliably repeat it, and it only happens under specific circumstances. I think it happens at around 9k rpm, but I've only caught a glance at the tach once, so I don't know if that's always the same.

 

[bricksrheavy]

...
there is an abrupt stop/start to power delivery that lasts less than half a second. The engine tone doesn't change much, so it seems like it has to be something in the transmission...

Had the exact same symptom when my kill switch started to act up, once it got worse (and it got worse in a matter of weeks) it began shutting the engine off mid ride.

Only thing, if this ONLY happens to you in 2nd gear then we can rule the kill switch out.

 

[Motogiro]

A common intermittent source is tbe kill/red/emergency switch. You might make a temp jumper to see if the glitch is eliminated. Sometimes it is a frequency specific vibration that causes a fast make/break connection.

Sent from Moto's Motorola

 

[TownsendsFJR1300]

Had the exact same symptom when my kill switch started to act up, once it got worse (and it got worse in a matter of weeks) it began shutting the engine off mid ride.

Only thing, if this ONLY happens to you in 2nd gear then we can rule the kill switch out.

Not necessarily...

If the vib's are just right at only that RPM/load, it could indeed be the kill switch...

Zixaq, do you use the kill switch regularly?


Plus one on by passing the switch for testing purposes...



.

 

[zixaq]

Not necessarily...

If the vib's are just right at only that RPM/load, it could indeed be the kill switch...

Zixaq, do you use the kill switch regularly?


Plus one on by passing the switch for testing purposes...



.

I've used it on purpose maybe twice?

For chuckles I turned it off/on really fast the other day while riding, has a totally different feel/sound than the symptom I'm describing.

 

[Motogiro]

Could be clutch related but I would think it would show other than just 2nd gear. The other might be to double check that front sprocket to make sure it's secure on the spline. Make sure all the cush drive inserts are sound and present. Check the swing arm bearings. Why only second gear? Check that your side stand is snug and check the side stand safety switch and wires.
If you want to eliminate the kill switch you would have to jump it. You can't turn it on and of at hundreds/thousands of times per second by hand. If it is frequency related to vibration, you'll want to run a jumper.

 

[TownsendsFJR1300]

On rare occasions, the side stand switch can fail and cause issues. It's pretty easy to R & R clean-re-grease.

Flipping the kill switch momentarily most likely will NOT "feel/sound" the same as IF it was worn/crappy contacts inside, especially under load at high RPM's.

I would jump that RED kill switch WAY before pulling the clutch. It's a common and documented issue.

If the clutch is not slipping/acting up in FIRST GEAR, it's very, very UN-LIKELY to be your issue nor the transmission..

 

[zixaq]

Thanks for all the help, but it looks like resolving this is going to have to be put on hold for a month or two while I heal up and fix more obvious problems.

I went down hard (although not going very fast) last Thursday and just got out of the hospital on Sunday. Bike lost the right footpeg, bent the handlebars and dented the tank up pretty good. Looks like it was probably a highside. I escaped with a few broken ribs, bruised lung, small pneumothorax and a medical bill that I haven't seen yet but already has me sweating bullets. I don't actually know what happened, as I can't remember it except for a few scary images. Seems weird that I would just highside out of nowhere on flat, straight road at 30 mph, but if someone else clipped me they didn't stop, so I'll never know.

 

[TownsendsFJR1300]

Wow!! Heal up, the bike will still be there...

 

[Motogiro]

Thanks for all the help, but it looks like resolving this is going to have to be put on hold for a month or two while I heal up and fix more obvious problems.

I went down hard (although not going very fast) last Thursday and just got out of the hospital on Sunday. Bike lost the right footpeg, bent the handlebars and dented the tank up pretty good. Looks like it was probably a highside. I escaped with a few broken ribs, bruised lung, small pneumothorax and a medical bill that I haven't seen yet but already has me sweating bullets. I don't actually know what happened, as I can't remember it except for a few scary images. Seems weird that I would just highside out of nowhere on flat, straight road at 30 mph, but if someone else clipped me they didn't stop, so I'll never know.

Ouch! Sorry to hear you were injured. Take your time. If you have broken ribs It will be a while before you're safe to ride again. Broken ribs are painful. You'll get an idea if you sneeze or have to cough. Don't ask me how I know....

If you don't remember what happened beware you were experiencing a glitch with the bike and now you want to confirm that something on the driveline or other part of the bike did not fail.

Get better!

 

[zixaq]

So I just payed for a month of unlimited access to a garage and tools so i can fix the bike up and store it. While I have that, should I just go ahead and tear into the engine to look at the transmission?

I'm a little spooked at the prospect, because it's well beyond my mechanical experience, but I want this problem gone.

 

[TownsendsFJR1300]

There's very likely NOTHING wrong with your transmission.

Several most likely issues have been mentioned. Have you addressed any of them?

Seems your going to "tear into it" anyway.

Please post back what you find or don't find...

 

[zixaq]

There's very likely NOTHING wrong with your transmission.

Several most likely issues have been mentioned. Have you addressed any of them?

Seems your going to "tear into it" anyway.

Please post back what you find or don't find...

I certainly hope you're right. Exactly one issue has been mentioned and I haven't had a chance to troubleshoot it yet (kill switch), and is going to be really hard for me to troubleshoot any time soon safely. I'll be able to work on the bike a few weeks before I can get out and ride it hard enough to reproduce the problem.

I also find the kill switch explanation incredibly implausible.

 

[trepetti]

I certainly hope you're right. Exactly one issue has been mentioned and I haven't had a chance to troubleshoot it yet (kill switch), and is going to be really hard for me to troubleshoot any time soon safely. I'll be able to work on the bike a few weeks before I can get out and ride it hard enough to reproduce the problem.

I also find the kill switch explanation incredibly implausible.

As implausible as the kill switch may seem, it is nearly impossible for the transmission to be causing the issue. Start with the some stuff.

Sent from my SM-G930V using Tapatalk

 

[TownsendsFJR1300]

As implausible as the kill switch may seem, it is nearly impossible for the transmission to be causing the issue. Start with the some stuff.

+100 x's ^^^.

It's very well DOCUMENTED with similar "Skipping or momentarily misfire"..

IME, start with basic's first.

BTW, short of you exploding your clutch (doing burn outs) and getting clutch "pieces" thru out the engine and transmission, that gear box is about as solid as a rock...

Been on this forum for 9 years, (and owned the bike for the same- besides wrenching for 46 YEARS) and do a lot of reading/learning here. Never heard of the issue on other bikes, the FZ, like any other bike, has it's issues.

Fortunately, the issues are pretty minor in 99% of the cases.

 

[zixaq]

+100 x's ^^^.

It's very well DOCUMENTED with similar "Skipping or momentarily misfire"..

IME, start with basic's first.

BTW, short of you exploding your clutch (doing burn outs) and getting clutch "pieces" thru out the engine and transmission, that gear box is about as solid as a rock...

Been on this forum for 9 years, (and owned the bike for the same- besides wrenching for 46 YEARS) and do a lot of reading/learning here. Never heard of the issue on other bikes, the FZ, like any other bike, has it's issues.

Fortunately, the issues are pretty minor in 99% of the cases.

I'm going to check it, but I don't expect that to be the problem, since the engine doesn't misfire or stop. The symptoms don't really fit.

 

[Motogiro]

I'm going to check it, but I don't expect that to be the problem, since the engine doesn't misfire or stop. The symptoms don't really fit.

Maybe this will help regarding why we like to check the kill switch when there is a power issue. The coils both get power from the kill switch as well as other feeds that it takes care of.

There are specific resonant frequencies depending on frequency length or distance a device is from the source vibration as well as mechanical stability of objects the energy travels through. In fact, there are too many factors to consider related to a mechanical switch failure due to vibration. I can tell you they do exist and they are worth eliminating to prove the kill switch is, or is not, at fault. This means that the switch might be opening and closing hundred or thousands of times per second. This would mean that power to the coils would be interrupted hundred to thousand of time per second this would certainly interfere with dwell so that the coils would build and collapse the magnetic fields differently, degrading the spark from the secondary high tension side of the coil.

So running a jumper on the kill switch would eliminate it as the source of intermittent reduction in power delivery to the bike. You don't have to learn any theory just try the suggestion. From years of experience, collective knowledge of others and a very large and effective forum full of information, you could come up with the solution to your problem.


Here's one....Years ago, a member in IIRC, the UK, had a problem with his engine stuttering. It only happened when he accelerated in gear. It would not occur at idle or in neutral. He could rev it and there was no glitch at all. The idle was smooth as long as the bike sat in one spot. Put the bike up on the center stand and put it in neutral. If the back wheel rotated the engine stumbled. Stopped the back wheel from turning and the engine would run fine. What was it?
Tune in next time for the answer! LOL!

 

[zixaq]

Maybe this will help regarding why we like to check the kill switch when there is a power issue. The coils both get power from the kill switch as well as other feeds that it takes care of.

There are specific resonant frequencies depending on frequency length or distance a device is from the source vibration as well as mechanical stability of objects the energy travels through. In fact, there are too many factors to consider related to a mechanical switch failure due to vibration. I can tell you they do exist and they are worth eliminating to prove the kill switch is, or is not, at fault. This means that the switch might be opening and closing hundred or thousands of times per second. This would mean that power to the coils would be interrupted hundred to thousand of time per second this would certainly interfere with dwell so that the coils would build and collapse the magnetic fields differently, degrading the spark from the secondary high tension side of the coil.

So running a jumper on the kill switch would eliminate it as the source of intermittent reduction in power delivery to the bike. You don't have to learn any theory just try the suggestion. From years of experience, collective knowledge of others and a very large and effective forum full of information, you could come up with the solution to your problem.


Here's one....Years ago, a member in IIRC, the UK, had a problem with his engine stuttering. It only happened when he accelerated in gear. It would not occur at idle or in neutral. He could rev it and there was no glitch at all. The idle was smooth as long as the bike sat in one spot. Put the bike up on the center stand and put it in neutral. If the back wheel rotated the engine stumbled. Stopped the back wheel from turning and the engine would run fine. What was it?
Tune in next time for the answer! LOL!

I understand the absurdly simple theory, but since the engine keeps running, which requires continuous electrical current through that switch, it still doesn't seem to match the symptom.

As mentioned several times, it's easy to check and I will do so, as soon as I'm healed up enough to ride, but I'm still looking for other ideas when it turns out to be not the problem.

 

[Motogiro]

I understand the absurdly simple theory, but since the engine keeps running, which requires continuous electrical current through that switch, it still doesn't seem to match the symptom.

As mentioned several times, it's easy to check and I will do so, as soon as I'm healed up enough to ride, but I'm still looking for other ideas when it turns out to be not the problem.

It seems like it's not that simple a theory.
The theory is that there is continuous direct current through the switch but the duty cycle is reduced at specific frequency's. The only time there would be a complete failure would be when current has been reduced below a threshold to keep an error from occuring or the switch becomes open long enough for a engine failure.
Think of it as if the switch passes current on and off 7, 000 time per second or 2,000 times per second. The off time and on time during the anomaly may not be even cycles but the coils will change their performance and you may experience degrade engine output during the anomaly. The switch would not be open long enough to stop the engine but it would be providing DC pulses at varied rates.


Sent from Moto's Motorola

 

[Gary in NJ]

[said in your best Yoda voice]

Stubborn is he.