B5 noise

[shamelin]

My B5 just started making some horrible noise.  I was hoping some of you wiser enthusiasts may have some suggestions.

I've never had a problem like this before.  Rode my B5 to work yesterday; about a 20 mile commute at speeds up to 70mph.  No noise then.  When I got on my bike for the commute home, it started making this medium pitched vibratory noise at high RPMs.  I thought it might be the headlight assembly (I've had some minor rattling before) so I headed home with the annoying noise, but no loss of power or other problem. 

Today I changed my oil, lubed my cables, greased my pivot points, and took of the headlight assembly to find the problem.  Needless to say, it wasn't the headlight.  Once I was off the bike and sans helmet, it sounded like was coming from the engine.   

The B5 starts without difficulty and sounds just like it always did during idle and low RPMs.  When I get the RPMs up in any gear, that's when the noise starts kicking in.

Here's a video with me revving 3 times in neutral:

http://youtu.be/u4tRCtMSS-4

Any suggestions would be warmly appreciated.

[Arizoni]

Boy!  At last a video that I can hear what the poster is talking about.

That's also a very nasty noise.

I might guess a connecting rod big end bearing but usually they don't wait in the background and then suddenly start whacking at a specific speed.

A less serious thing that might be doing it is the duplex primary chain if the automatic tensioner isn't working??  That might allow the chain to start shaking at some speeds while it could run smoothly at slower speeds?

Along with you, I'll be very interested to find out what it is.

[barenekd]

Check your tank mounting bolts.
Bare

[mattsz]

Ohh, Shamelin - I sure hope it's something simple, like bare's suggestion!  It's hard for me to shake the feeling sometimes that my B5 isn't quite right - idle is still wacky; decompressor clatters at higher speeds than I think it should (at least until it warms up); fuel economy isn't quite what other guys are getting despite my non-aggressive riding style - and it's hard not to assume that it's because I bought the "cheap" model.  But of course, the engine is the same.  I have no experience to go on...

Sorry I can't offer any useful advice, but I'm pulling for ya!

[barenekd]

It's hard for me to shake the feeling sometimes that my B5 isn't quite right - idle is still wacky; decompressor clatters at higher speeds than I think it should (at least until it warms up); fuel economy isn't quite what other guys are getting

The reason I can tell you how it all stacks up, like the vibration, My tank rear bolt came loose and made that noise, my decompressor clatters for a few minutes every time I start it from cold. I do get good mileage, but I don't generally ride it very fast on the highways. If I do speed up to 70 indicated, which with the new tires isn't very fast, my mileage drops precipitously! I found between 60 and 65 will give decent, above that forget it. If I'm riding in the mountains, it doesn't matter so much as teh altitude is what saves the gas. Since you generally ride at sea level, I presume, your mileage is not going to be as good as mine, since my bike spends over 50% of the time in the mountains.
As far as the idling goes, the more miles it gets the smoother it will get. How many miles is on yours now?
Don't be so impatient, my man, it will get there. It doesn't sound like there's anything wrong with your bike to me. Put in earplugs and keep on riding!
Bare

[motorat]

along with the tank check the bolts in all the boxes...air fliter-tool box and electronics.
the it appears the noise doesnt start until you get the vibrations up then it sounds like a bolt bouncing in a coffee can.

[mattsz]

Bare - I don't want to hijack Shamelin's thread, but...

I don't believe I've ever had it above 65 mph - was hoping for better than 60mpg, but it is what it is, I guess, as long as there isn't something wrong.  Someday I'd love it if you'll tell me about why it is that sea-level mileage should be worse than high-altitude mileage.  Another time.

As for my idle: it's smooth, I just never know where it's going to end up when I stop moving.  When I start it cold, it's pretty reliably at about 1000 rpm.  Once it's warmed up, it's a crap shoot - Maybe 1000 rpm, maybe 1800 or even 2000 rpm, I never know.  I have people look at me funny with my engine racing (well, racing for an idling single) at stoplights; I just shrug at them and move on when the light turns green.

I'm up to a patriotic 1776 miles.  And I can't be anything but a patient grasshopper now, since my bike is under cover for the winter! 

[JVS]

Mattsz, have you tried adjusting/checking the brass screw that can adjust the idle? Maybe there's a weakpoint at that spot? Breather pipe? Throttle cable play or some issue at the throttle body behind the RH 'Royal Enfield' cover? Loose ECU connections in the LH tool-box? Checked Air filter? And the rubber hose connecting the air filter to the throttle body?

Your idle really shouldn't fluctuate that much, even though the EFI tends to go up and down in idle, but those are some big jumps you are having. I'm aware your dealer is quite far, but you might need to take the bike over to them. Get it sorted once and for all. 

[GlennF]

My B5 idle hunts more with the stock spark plug. It also hunts if you adjust the idle too low. A slightly faster idle tend to be more stable.

[JVS]

Yeah I don't know whether this will have an effect on your idle, but make sure the spark plug gap is 0.7mm-0.8mm. I have the NGK BPR6ES and I set it to 0.7mm. It never fouls, runs well (neither lean nor rich, thankfully). The stock plug always fouled up for me =/

[Desi Bike]

Can you hear where the noise is eminating? Maybe acardboard tube held at various places on the bike while running it. There has been a couple of bikes with a bolt that came loose in the primary chain area. Don't ride it like that until you  can figure out what it is. Don't want any unintended rear wheel lock up.

[jartist]

I second the tank mounting bolts.  I've had that noise come on at medium to high revs come from the front and rear bolt on different occasions and it doesn't damp out with hand pressure, you really have to sit on the tank to make the vibration go away unless you get the two tank bolts torqued down right.  I don't remember what the torque setting was but I basically looked up a torque spec chart for the size and grade bolt and used that figure.  Other spots to check are the heat shield on the exhaust and the battery mounting tray.  Good luck and let us know what you find!

[jartist]

@ mattsz:  FWIW I get 58 mpg that I track on Fuelly.com.  http://www.fuelly.com/driver/jartist/bullet
I have a fairly large torso and I think that I am a bit of a sail but I don't notice too much of a difference in whether I drive fast or slow or two up or solo.  I wouldn't get alarmed about something being amiss unless you were getting mileage in the 40s.

I seriously doubt there's any difference in the engine internals between a B5 or a C5.  Most people including me say that the engine continues to sweeten well into the 2000 and 3000 mile mark.

[singhg5]

The fuel tank bolts are set at 37 Ft-lb. torque. 

The sound seems to come from front tank bolt or stearing stem area or loose nut of ignition coil. Does not hurt to check exhaust pipe at cylinder head and headlight nacelle.

From the video, I can't make out the exact source of the noise. May be you have a better idea by now.

[Ducati Scotty]

Mattsz, not everyone get 8,000,000 MPG.
http://www.fuelly.com/driver/ducatiscotty/classic-500

60 is fine.  Keep in mind the advertised 75mpg is for an Imperial gallon, about 20% larger than a US gallon.
http://en.wikipedia.org/wiki/Gallon#Definitions

Scott