Now that I have my 1983 Vision running I have been riding it a bit. Once the DMV opens for regular business I can go get a title and registration.
The last couple of rides I have noticed and strange rhythmic whirring sound. I first noticed it when I came to a stop and it would be there for a few seconds and then stop and everything sounds normal. The last ride I tried to diagnose a bit more and it was there at low speeds and I thought it might be a sound from the front brakes but it is there after a complete stop so nothing but the engine is rotating.
The bike runs great and idles nice and smooth. It does not seem to be reproduceable just sitting and revving the engine, it only happens when ridden and slowing down. It is not possible to hear it at higher speeds because everything else is louder so I have no idea if it is there all the time. IT stops after a few seconds at idle so it does not seem to be mechanical.
You might put the bike on the center stand and go through the gears that way and see what you can hear. Apply the brakes gently as they will really overpower the rear wheel since there isn't any mass to stop per se. I can't imagine what would keep spinning after coming to a stop. Maybe the clutch as the reverse forces on it are doing something.
Radiator fan? Need more clues.
Since this happens when coming to a stop I think it might be the transmission almost in/out of gear. The main shaft spins with the clutch basket inertia and is coupled to the crank shaft, so it is spinning as long as the engine is running. The counter shaft / output shaft is coupled to the rear wheel via the drive shaft and middle gear. Engine speed controls the main shaft and road speed controls the counter shaft. I have a feeling that when you shift "out" of gear (into neutral) when coming to a stop that the shift drum is not completely set at a prescribed detent position. Like getting a false neutral between gears, except it is just not quite totally in the neutral position and the dogs on the gears can rub against the opposing set of dogs. Does this sound happen when the neutral light is ON?
An important point about shifting gears is that the shift lever be moved firmly and securely into the 'next' position. NOT stomped or jammed because the speed of that motion transfers motion to the shift drum, and the inertia of that part rotating can carry over a bit just past it's intended detent position, leaving gears slightly out of position and they can rub.:police:
Or maybe the noise is coming from a harmonic resonance of some body part(s).
Starter clutch?
" strange rhythmic whirring sound"
Or something rubbing on a wheel while braking?
It could be the tool kit buzzing under the seat, being excited by a resonant frequency, or loose parts in the exhaust, system or . . .
I guess we will just wait until we hear what causes the noise. 8)
I have had a similar noise on my machine as well; it was erratic and usually stopped a few seconds after I stopped the bike.
It turned out to be my speedo. Although the cable was well lubricated, the speedometer head had gone dry. Some WD40 or CRC spray lube with a straw attached and squirted liberally into the speedo housing at the speedo cable joint sorted the problem for me.
Try removing the speedo cable drive and see if it stops making the noise you are hearing for a quick diagnosis.
Very good possibility.
Also, a point to remember: never store a mechanical speedometer or tach with the face down, always face up. There is a small reservoir of oil inside to damp the movement of the needle, and this can slowly leak out if the meter faces down. I learned this when I worked at a dealership a hundred years ago.
My strange noise was first noticed AFTER coming to a complete stop. I have done enough investigating to be pretty certain it is not at all something mechanical rotating. Yesterday it did only once or twice and was not as long as before. I am thinking it may be related to the fuel pump and the return to the tank. It is a 1983. With a lower fuel tank yesterday maybe that is why it decreased.
I had considered the speedometer but since it persists after coming to full stop I don't see how that is possible.
Could it be the tacho cable? The sound may change when moving air hits it and slightly bends it, or perhaps it is not fastened properly at one end or has a broken/frayed inner. Then again, it could be the tacho itself.
Electric tach on these.
Quote from: Walt_M. on July 14, 2020, 04:31:43 PM
Electric tach on these.
Ha ha ha - oops! Too much valve spring soup!
My speedo noise used to carry on a bit AFTER I stopped. I think this was because the head unit was dry and the cable gained some twist energy which dissipated after the wheel stopped turning. The lube method I described solved the problem.
At slow speed I could hear the whirring noise, it was however, erratic, as you describe. At higher speed the whirring was drowned out by the engine noise. The speedo needle was pretty jumpy though.
pinholenz, I will check out the speedo lubrication. My needle is not erratic but it is worth a shot.
Coolant purging into the overflow recovery bottle.
Quote from: fret not on August 11, 2020, 03:47:23 AM
Coolant purging into the overflow recovery bottle.
I heard that on my XZ yesterday. I stopped after a spirited ride then let it idle at home for several minutes before shutdown. Afterward I heard the gurgling sound.
Quote from: fret not on July 12, 2020, 04:05:21 PM
Since this happens when coming to a stop I think it might be the transmission almost in/out of gear. The main shaft spins with the clutch basket inertia and is coupled to the crank shaft, so it is spinning as long as the engine is running. The counter shaft / output shaft is coupled to the rear wheel via the drive shaft and middle gear. Engine speed controls the main shaft and road speed controls the counter shaft. I have a feeling that when you shift "out" of gear (into neutral) when coming to a stop that the shift drum is not completely set at a prescribed detent position. Like getting a false neutral between gears, except it is just not quite totally in the neutral position and the dogs on the gears can rub against the opposing set of dogs. Does this sound happen when the neutral light is ON?
An important point about shifting gears is that the shift lever be moved firmly and securely into the 'next' position. NOT stomped or jammed because the speed of that motion transfers motion to the shift drum, and the inertia of that part rotating can carry over a bit just past it's intended detent position, leaving gears slightly out of position and they can rub.:police:
Or maybe the noise is coming from a harmonic resonance of some body part(s).
Seems reasonable. My XZ only has 16k miles on it and sometimes finding Neutral is a challenge. Shifting to N is easy from 2nd and difficult from 1st. I was thinking detent wear or similar.
Any other info on the engine/trans? Mileage? Difficulty in gear selection? Clutch actuation good?
Quote from: injuhneer on August 22, 2020, 12:26:33 PMsometimes finding Neutral is a challenge. Shifting to N is easy from 2nd and difficult from 1st. I was thinking detent wear or similar.
I used to have a lot of trouble finding neutral, and changing gears was pretty chunky. I'd figured wear also (and it probably was). Doesn't mean you are stuck with it.
I switched to Castrol Power1 GPS Semi-synthetic oil back in 2009/2010
That cured my shifting problems and the bike idles smoother, accelerates better. Like a whole new bike
Quote from: Prophet Of Doom on August 22, 2020, 05:42:14 PM
I used to have a lot of trouble finding neutral, and changing gears was pretty chunky. I'd figured wear also (and it probably was). Doesn't mean you are stuck with it.
I switched to Castrol Power1 GPS Semi-synthetic oil back in 2009/2010
That cured my shifting problems and the bike idles smoother, accelerates better. Like a whole new bike
I guess that is a simple fix. My starting point used to be a 15w-40. I am wondering about the condition of the detent mechanism. At low mileage I can't imagine it to be very worn. Although the shift lever could have been abused.
I have had the same experience as POD changing over to Amsoil 100% synthetic 10w-40. The engine just kept on improving for the next 2000kms. Awesome stuff, the downside being that its a premium price oil here in NZ. Amsoil has got an interesting backstory to their product.
Well I may have an opportunity to test it out (or more correctly confirm your report).
The starter went out on my bike. :'(
Not to hijack this thread but I took it apart to find the positive brush lead broken. As luck would have it I had a set of new alternator brushes from a XJ650LJ. The leads are slightly shorter but the brushes were a direct fit.
I soldered them in and have started reassembly.
I need to look inside the engine (or manual) to verify clearance but I was wondering why there is no slinger on the starter? The starter nose sits in oil as we all know. I was thinking about making a slinger to go behind the gear to shed the oil when the starter is activated. Of course I don't know what the output RPM is so it may be too slow to matter.
Quote from: injuhneer on August 29, 2020, 11:44:23 AM
I was thinking about making a slinger to go behind the gear to shed the oil when the starter is activated. Of course I don't know what the output RPM is so it may be too slow to matter.
A slinger won't stop it from being below the oil line when the bike is parked. Of course if you'd rather build a slinger, but I think your time better spent on improvements that don't have a $5 solution.
If I recall correctly, the original starter oil seal was a single lip seal.
If you replace with a dual lip seal (which was all I could find anyway) it should last a good long time.
Perhaps get a spare to replace after 5 years or so.
I suppose. The point of the slinger is to shed during rotation. It is not to add sealing. On a seal with two contact surfaces the wiper lip really is designed to prevent debris passing inward. In this case from the planetary case toward the engine. The seal portion should be the same.
What would really help is to reduce the shaft size at the sealing surface. Lower surface speed. Less annular area to leak. Less seal lip section to fatigue.
Or not.
Follow-up edit:
Regardless the starter rebuild was worth the effort. With the new brushes and freshly surfaced commutator it spins noticeably faster which improved starting.
As expected. :-)
It was the speedometer. I had not ridden the bike for a while and the noise had gone away. But yesterday it was back more pronounced than before. So I removed the speedo cable at the wheel and the noise stopped, then returned when reconnected.
I will have to open the speedo and clean & lube.
So, to clarify this situation, your speedometer/cable would make a rhythmic noise AFTER a stop. Is that correct?
I think I would start with lubing the cable real good and see what happens then. It's a lot easier to do than taking the speedo off and apart.
Quote from: fret not on October 27, 2020, 09:33:27 PM
So, to clarify this situation, your speedometer/cable would make a rhythmic noise AFTER a stop. Is that correct?
How? There is nothing moving at rest.
No, not after stop. While I was moving and then it would stop once I got to almost no forward velocity.
The cable is lubricated VERY well. It is a bit of a hassle to remove the speedo with the fairing but opening it up is trivial after that.
Quote from: kevin g on October 28, 2020, 08:45:16 PM
No, not after stop. While I was moving and then it would stop once I got to almost no forward velocity.
The cable is lubricated VERY well. It is a bit of a hassle to remove the speedo with the fairing but opening it up is trivial after that.
Ah! OK. I misunderstood. LOL