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1994 K75S High-pitched chirping noise when hot?

Thanks again, guys. Although I haven't ridden the bike again yet I really do have a hunch that the problem is solved.

I did blow through the filter afterwards but I think I might have been blowing the wrong way. There wasn't much resistance as I recall but it's only the second time I've ever dealt with a K bike filter thusly. Coincidentally, the same day I was blowing through the filter I had been blowing through some elaborate medical apparatus during a clinical research study of lifelong non-smokers I was participating in to determine my lung capacity!

So even if there was any resistance in the filter I might not have been able to notice it as I was blowing as hard as I could about a dozen times earlier that day.:D

I'll post a followup next time I go for a decent ride which may be later today; been moved in for a couple of months now and I've hardly begun to discover all the great roads around Albuquerque yet.:eat
 
Good news

Just got back from a 136-mile ride that I made kinda on the spur of the moment. Left at 3:30pm local, got back about 3 hours and 20 minutes later. All two-lane.

For those of you familiar with New Mexico, my route was ABQ-Carnuel-Tijeras-Escobosa-Chilili-Estancia-Tajique-Torreon-Punta de Agua and my "destination" was Quarai Nat'l. Monument. Spent 10 minutes there to take another look at the ruins of the huge old church there (last visit was in 1979) and then I turned arouund and headed home.

It was a gorgeous puffy-white cloud New Mexico summer afternoon and the ride was PERFECT.

Not a whimper, screech or chirrrrrrrp was heard the whole time.

Wow, what a feeling!
 
The chirp is back

No problems until my next longer ride on August 7th. Near the tail end of the 145-mile loop the chirp popped in a few times for a few seconds.

With a couple more rides around town about a week later the chirp was definitely back and as loud as ever. The last ride it was screeching and warbling like a police whistle (UK) and when I pulled onto the driveway I got off and got down next to the running engine. It was so loud I coudn't tell where it was coming from.

While I already went back to Napa and got another fuel filter to have on standby I am now wondering about another possible culprit that's making the noise.

I noticed that my headlight and aux. lights were dimming a bit at idle like when I was sitting at a stoplight at night; something I haven't noticed before at all. Could the alternator be making all the racket? Maybe the brushes are wearing out or? Another possible clue is the fact that when I went out to the garage to start the bike (was planning on another 125-mile RT to Santa Fe today)---the battery was too dead for the indicator lights to come on. Leads me to believe my alternator hasn't been charging much at all (I also did have a loose battery connection that I discovered and fixed on the 6th, though).

Sorry to be back here with the bad news so soon after what I thought was the fix (and may still be if there was some junk left in the tank after I replaced the fuel filter).

If anyone knows of such a thing as a chirping alternator on a K bike, do let me know. Meanwhile, the battery is being charged with my trickle charger for a good long stretch.

Otherwise, I'll go ahead and replace the filter again despite the very short time it's been installed. Could be another batch of bad gas, too---who knows?
 
The noise you describe arrived with smaller fuel pump fitted from 1993. It tends to occur with hot fuel and/or low fuel levels. A Service Bulletin from that era advised us to install a length of submersible fuel line to the return pipe in the tank and to direct the hose over the fuel pump.
 
Interesting news; I suppose the extra fuel pouring over the fuel pump would serve to cool and or quiet it down, right?

My best option might be just keep the tank filled up as I know that no K75 fuel pump likes a low level to begin with.

Now I am wondering if this is a telltale sign that my fuel pump is going to need replacing sometime soon. When I took it out to inspect it and replace the in-tank fuel lines/filter and pump sock three years ago the rubber surround was firm and intact---so I don't think it's any kind of goo issue---at least.

Anyone else care to weigh in on this? Perhaps my alternator issue (if it is also going faulty on me) is a coincidence in the first place. Oh, woe is me; almost all of the things my bike needs done (new fork seals, new front wheel bearings, valve adjustment, alternator(?) and fuel pump(?)) are either beyond my limited expertise, capacity or budget these days.:violin

Thanks for the insight, Lost Boy, though; it helps.
 
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Those pumps were noisy even when the bikes were new. Hence the service bulletin. Installing the hose in the tank is not expensive or terribly difficult.
 
I could do this mod but I need a bit more info;

I still have some leftover in-tank fuel line from my partial renovation done three years ago. Where, exactly is that point that I would attach it to before positioning the other end over the fuel pump, please?
 
I'de like to see where this run of fuel hose goes too, as I have one of these newer style pumps in a very early K-100RS.
 
Extra fuel line in the tank is not going to make one iota of difference!

I filled up the tank again today thinking that the fully submerged fuel pump might behave thus but that notion was quickly dispelled. Still as noisy as ever.

I think that idea of running a fuel line over to the pump is nonsense; yet I will be the first to apologize should/could I be proven wrong. No amount of fuel is going to cool it down enough to be quiet.

I suspect that my pump is beginning to die or wear out---nothing more or nothing less.

Hope that it's not a dangerous situation brewing as I ride around New Mexico in the 90+ degree heat and the pump (or something inside the tank, presumably) chirping like a canary on steroids. How do fuel pumps die?

Curious to hear any stories about other's going south and whether it is usually sudden or long and drawn out. :scratch

---Perplexed in ABQ
 
Sound advice is welcome!

I filled up the tank again today thinking that the fully submerged fuel pump might behave thus but that notion was quickly dispelled. Still as noisy as ever.

I think that idea of running a fuel line over to the pump is nonsense; yet I will be the first to apologize should/could I be proven wrong. No amount of fuel is going to cool it down enough to be quiet.

I suspect that my pump is beginning to die or wear out---nothing more or nothing less.

Hope that it's not a dangerous situation brewing as I ride around New Mexico in the 90+ degree heat and the pump (or something inside the tank, presumably) chirping like a canary on steroids. How do fuel pumps die?

Curious to hear any stories about other's going south and whether it is usually sudden or long and drawn out. :scratch

---Perplexed in ABQ

Anyone?
 
Usually the first symptom of a pump going out is the bike goes quiet and coasts to the side of the road never to start again. This entails the joy of trying to contact someone to come and get you and your bike. Just think of the hours of enjoyment you could have on the sunny side of the road listening to busy signals or being put on hold (if you can get a signal). Walking on a 90 degree day, leaving your "baby" in the middle of nowhere can lead to all kinds of surprises.

If you are SURE the noise is coming from the pump, why wait for the very inconvenient eventuality? Consider yourself fortunate that you are getting a warning while the bike is at home.

Have you pulled the pump and bench tested it? Have you inspected the lines inside the tank for leakage while it is running? Have you done a fuel pressure test to insure the regulator is working properly? Have you checked the filter again to insure it's not partially plugged again? Are all 4 hose clamps TIGHT?

I would not be out riding if I suspected my fuel pump was about to fail. The cost of a failure on the road is WAY higher than the cost of a new pump (if that's where you're SURE the noise is coming from and it's NOT a bad regulator or filter or hose).



:dance:dance:dance
 
Have you checked your fuel hoses for kinks, especially from the FPR to the tank? Are these the original hoses that came with the bike?
 
Have you checked your fuel hoses for kinks, especially from the FPR to the tank? Are these the original hoses that came with the bike?

The in-tank lines are fine as far as I can tell. I installed new lines three years ago even though the original ones were intact. I also installed a new pump sock which should (AFAIK) effectively filter the large bits of gunk (if any) floating around the tank.

I'm going to siphon the tank now and install another new fuel filter for one last check to see if a blocked or gunked up filter is causing the squealing. Thanks Ted for your input, too!
 
Usually the first symptom of a pump going out is the bike goes quiet and coasts to the side of the road never to start again. This entails the joy of trying to contact someone to come and get you and your bike. Just think of the hours of enjoyment you could have on the sunny side of the road listening to busy signals or being put on hold (if you can get a signal). Walking on a 90 degree day, leaving your "baby" in the middle of nowhere can lead to all kinds of surprises.

If you are SURE the noise is coming from the pump, why wait for the very inconvenient eventuality? Consider yourself fortunate that you are getting a warning while the bike is at home.

Have you pulled the pump and bench tested it? Have you inspected the lines inside the tank for leakage while it is running? Have you done a fuel pressure test to insure the regulator is working properly? Have you checked the filter again to insure it's not partially plugged again? Are all 4 hose clamps TIGHT?

I would not be out riding if I suspected my fuel pump was about to fail. The cost of a failure on the road is WAY higher than the cost of a new pump (if that's where you're SURE the noise is coming from and it's NOT a bad regulator or filter or hose).



:dance:dance:dance

This is all pertinent and logical and brings me to the realization that I am almost looking too hard into the forest to see the trees.

Yes, Lee, I agree that it is crazy to be riding around New Mexico in this heat (91 today)waiting for a potentially costly situation to develop so I am taking your advice to heart.

I will install another new filter once I finish typing this to see if it makes any difference at all. The other new filter I installed a few weeks ago seemed to cure the squeal at the time---but it was back again after less than 250 miles. Hoping that it could be blockage I'll try it one more time.

No I haven't taken the pump out to bench test it but that is something I could probably do. I do have several 12v DC supplies on hand so it should be easy to try outside of the tank and far from any gas. One thing, though; isn't it bad to run the pump without gas running through it? Maybe it'll be OK for a few brief times.

I suppose I would be wanting to see if it's noisy or not as well as running it backwards (reversed polarity) a couple of times in hopes of dislodging gunk, heh?

The fuel pressure regulator is something I know nothing about. Heck, I didn't even realize that there is such a device---there again, can't see the forest for the trees, I guess. Maybe that could be the culprit, too. Is that what Don was talking about a while back; the device that relieves the pressure if the fuel line/pump gets blocked?

Sorry, but I've not much of a clue as to where to look for it, either. In the tank or tucked away somewhere else? Yikes. This is a bit daunting but I'll await your response before proceeding further than installing the new filter today.

As I told Ted above the in-tank lines are only three years old and are OEM so should be fine. The outside lines are old, though.

Pretty sure all the clamps are tight but I'll double check them, too.

Thanks very much for your helpful advice and insight into this annoying situation.

As if this wasn't enough to deal with, my electrical system is acting up with the ABS relay apparently faulty as well as my auxilliary lights are all out now, too.

At least the new battery seems like a good move and I'll be getting new fork seals and wheel bearings installed after this fuel system problem is resolved.

Cheers, Jeff
 
I was on the US side two weeks ago and picked up a Craftsman automobile stethoscope; dirt cheap at Sears. We can't get that tool at Sears in Canada.

Maybe you could try that avenue and listen-in to ensure the noise is not originating from somewhere else. :thumb
 
That's another good idea, Ghyber and I believe our landlord already has one in his enormous and well-equipped shop. He's sponsoring an Airhead Tech Day this Saturday and although I only ride my Brick I was planning to attend and check it out anyway (may be some brick riders there).

If the problem is still present I will try listening with it to pinpoint the noise but I don't expect that to be easy; the noise is very loud and obnoxious to the naked (unhelmeted) ear!:hungover

Just installed the latest new fuel filter and am now going for a quick test ride as the sun sets in ABQ. Will report back tomorrow after a 2nd ride assuming I don't hear the noise again now.
 
So far so good...

A 25 minute test ride where the radiator fan came on and so far no screeching or other sounds emanated from my bike. Fingers crossed that it was just another clogged filter but will hold my breath until further test rides tomorrow.:thumb
 
Drain the old filter and let it dry out. Lightly blow through it. Is there ANY resistance?
More than the new filter?


:dance:dance:dance
 
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