rattling sound, not a snake

[Ed Miller]

Mine's clean now, too, though still not as clean as yours.  I tucked everything back together yesterday, but I suspect I wasted all that time.  My old timing chain, tensioner, and guide all looked nearly like new, at 97,000 miles.  That's probably what happens when you spend almost no time idling in traffic -- plenty of oil moving through there.  I saw nothing that could explain the rattling sound.  The mufflers pled innocent.  

I did notice that my neutral switch has started leaking but I don't think that's related.  I need to find a plug that will fit there, as I don't use the switch except to stop oil from running out that hole.

I'm waiting for the Beemershop to call me back so I can order an oil pan gasket and some other stuff.  

When I started the bike up to make sure the timing was still good, it sounded fine.  My timing mark still jumps around a bit at higher rpms.  I wonder if I have some play in my bean can or something.  I'm tempted to just ride the thing until the rattling starts again and try harder to isolate it, but I fear doing $$$$$ damage.  

[Luca]

Sprocket wear will cause jumpy timing marks even with a new chain and tensioner.  Still wouldn't hurt to take the pan off and have a look from underneath.  Maybe go back to the valve covers and have a real close look at the valve springs.  I think somebody here a while back had a spring break.

Otherwise I'd just start laying a hand on everything that could get loose and rattle...  Gas tank and fenders, tank cap, license plate, starter cover, electrics under the tank, side covers if you got them... maybe the airbox.  Motor mounts would be worth a check... probably shake like the dickens though if they were loose.

[Matt Chapter]

I think somebody here a while back had a spring break.

That would be me.. it didn't really rattle though, the performance just sucked.  I think it broke due to stress from landing on the left head cover during the process of binning it.

[Ed Miller]

Just an update:  yesterday I dropped the oil pan and found nothing interesting.  I looked up and saw no signs anything had been bouncing around inside the motor.  I drained the gearbox oil and removed the leaking-anyway neutral switch, and found nothing unusual in the gear box oil and nothing I could feel stuck to the magnet.  So when I get my new pan gasket today, I'll put it back together and ride it and see if the noise comes back.  I suppose it could be something rattling around in the clutch area but I'm not pulling the tranny just to see.  

I still haven't found anything loose on the outside of the bike, either.  

[montmil]

You don't have an old, loose, tooth filling that's rattling and amplified when you wear a helmet, eh, Cousin Ed?

Free change in the tool tray? Flux capacitor bracket failed? Loose nut behind the bars? Sun spots?  

[Tony Smith]

I still haven't found anything loose on the outside of the bike, either.  

It got lost in the noise when I posted previously, I am increasingly of the opinion that your problem was a temporary "hang up" in the oil pressure operated cam chain tensioner. This can happen from time to time, all it needs is a very small bit of grit to hang the tensioner right up. Stop engine, piston retracts, grit moves and then gets flushed away and (hopefully) into the filter or pick up screen next start.

See http://bmwmotorcycletech.info/timingchain.htm

[Ed Miller]

I had that article printed out in front of me when I did the timing chain, Tony.  And another one that was more directly a "how to" but not really detailed enough for me.  I hope you're right about your diagnosis.  I did take the plunger and spring out and examine everything there.

I did find some gravel on the shelf over the rear of the gearbox, when I had the center spacer out to replace my neutral switch.  (I replaced the switch with a slightly shorter bolt, M12 1.50, cut just a bit shorter than the original switch.)  But I doubt that gravel rattled, as it was well cushioned by dirty mud and leaked oil.  

I got the oil pan on last night and replaced all the fluids, and then the stupid thing wouldn't start.  7:30 at night, I decided to diagnose that tonight if I'm up to it after running 10 miles, or more likely, tomorrow after work.  Man I'm tired of feeding gas to my Toyota pickup; if I can't get the bike running Wed. I'm definitely bicycling the rest of the week.

[Bob_Roller]

Ed, when you say the bike won't start, does the starter operate, but the engine doesn't fire

[Ed Miller]

Ed, when you say the bike won't start, does the starter operate, but the engine doesn't fire

Yeah.  I got home around 9:00 last night and managed to pull the plugs and ground them -- no spark but it spins around fine.  I have my Chitech manual with me so I'll be going over the trouble-shooting guide to be ready to test stuff, if I get home in time to eat, lift weights, sell a Craigslist item,...  you know what, I think I'll ride my bicycle for the rest of the week.

What's weird is it started fine after I changed the timing chain, and nothing about dropping the oil pan  or changing my gear lube should have interfered with the ignition system.

[Ed Miller]

Well crud.  As I was afraid of, I pinched the wires from the bean can up to the ICU in two places.  I didn't realize that the inner ribs between the outer cover and the timing chain cover would meet, and I was only worried with the outer rim.  

I've read those plugs are no longer available.  Is that wire replaceable, because I'm not really interested in trying to splice those 3 tiny wires, in two different places.  I will probably just spring for the new electronic unit from ...can't remember which place right now, but it does away with the mechanical advance.  Mine was sticking for a long time, but I spend so little time idling that I didn't feel like messing with it.

Anyway, enough with the rattle -- I have showed my skill in snatching defeat from the jaws of victory.

[Bob_Roller]

You can splice the wires back together .

[Ed Miller]

You can splice the wires back together .

Yeah, after I posted I looked up youtube videos on splicing small wires.  I guess I still don't have an excuse to get a new bean can.  I'll take the wire out to the electric shop and work and (after putting up with some well-earned ridicule) ask if they have any more wire that guage and colors, and any really small shrink wrap for the individual wires.  I have some that will work for the whole thing.

[montmil]

Well crud.  As I was afraid of, I pinched the wires from the bean can up to the ICU in two places.  I didn't realize that the inner ribs between the outer cover and the timing chain cover would meet, and I was only worried with the outer rim...  I'm not really interested in trying to splice those 3 tiny wires, in two different places...

I too pinched one of the 22-gauge bean can wires twix the same interior rib. I was stranded on a Sunday afternoon out on the prairies of North Texas when the error exposed itself. Really unsure where I was but called Pretty Wife and gave her semi-coherent directions, asked her to drive out with the truck, ramp, tie downs and some cold beer. She did and I spliced n' soldered the wire/s without an issue.

Rick Jones at Motorrad Elektrix sells the new Alpha electronic bean can and it's a peach. A pricey peach.

First, remember to slip on a short bit of shrink tubing, then splice and solder. No biggie.

[Ed Miller]

I got it back together last night but only ran it long enough to set the timing.  I rode it to work today, and it seems fine.  My idle speed is a little low but I'm due to clean out the carbs and re-tune.  I think it's been 30,000 miles or more.

Anyway, no weird rattles.  I'd be happier if I knew what caused it in the first place, but so long as it's gone I'm happy.