Strange chain flailing noise and loss of power

[Melena]

Okay guys!  I need your help.
Had a wonderful ride today and luckily this happened near the end of the ride.  This is what happened.

I'm riding at a moderate rate of speed, not really fast, following my friend, on a narrow road with a good amount of traffic coming in to the town of Sebastopol from the coast and I suddenly hear a terrible sound coming from the bike.  

This sound was like a chain coming loose and getting tangled up in something.  There is a sudden loss of power and I pull over to the very narrow little strip by the side of the road.  The bike has stalled, and the 2 top red idiot lights are on.  Okay.  I try to put it in neutral and it won't go.  Can't seem to change gears at all.  I don't recall a chain on my bike as it's a shaft drive.  Hmmmm.  I look around but don't see any problems on the outside.  Luckily there is a wide driveway just behind me so I get it pushed back to there with the help of a passerby.  

Another lucky thing, there is cell service here.    Good.  I call my friend and he's waiting for me up ahead.  He comes back and tries to start it, but it doesn't turn over at all.  He does get it into neutral, but no luck in starting.  So, he goes and gets his truck and trailer and I sit and read in the sunshine (nice to have a book around in these circumstances  - The "Tao Te Ching" even   )  

So, now the bike is on the trailer waiting until tomorrow when we can get a better idea of what's going on.  The idea of the chain noise got us to thinking about the timing chain.  Has anyone had their timing chain come apart while riding?   What would that sound like?  Or is it the transmission?  Or is it something more sinister?  

[Bob_Roller]

Sorry to hear of your incident !!!

I would start, by draining the oil out of the engine, transmission, shaft and final drive, to see if you can narrow it down a bit .

[nhmaf]

If it really is a chain sound, you may have had the timing chain come apart of the tensioner on it break and rattle about in the timing case.

But I would first drain all the oils out as Bob suggested and look for (and hope not to find !) metal pieces in the various locations.    Hopefully it is something that can be easily repaired without too much $$.

When my clutch splines let go on me it also produced a terrible racket - sort of like a 50 HP food processor with some bolts and screws tossed into it.   If that is the case - you won't find any bits of metal anywhere in any of the oils, and the timing chain will appear OK, - you'll have to pull the transmission off to see the damage in that instance.

We'll have our fingers crossed for you !!!
 

[Bengt_Phorqs]

Mike, if it was the splines wouldn't the bike still go into neutral or shift?  I've never had either one go bad on one of my bikes but since the spline is behind the tranny it seems like function would still be there.

Also, if the timing chain parted is there a possibility of valve damage?

[msbuck]

Mike, if it was the splines wouldn't the bike still go into neutral or shift?  I've never had either one go bad on one of my bikes but since the spline is behind the tranny it seems like function would still be there.

Also, if the timing chain parted is there a possibility of valve damage?

If it's the clutch splines/input shaft splines to the gearbox, you're dead in the water.  Well, the bike runs, but when you shift gears you get no power to the wheel.  It happened to Graham out in Oregon - he's seen it TWO many times.  There's usually symptoms just prior to the spline going as well.  Hard shifting, etc.  When his input shaft failed it went....ring-a-ding-a-ding-a ding-a ding (not like nuts & bolts in a food processor)

Melena, how many miles are on your bike?  Per Leon Friday of Scooterville BMW, He "never had to replace a timing chain on a boxer motor."  Unless the bike has 100k miles on it or more, Graham wouldn't even suspect the timing chain.  IF it is the timing chain, then possibly the tensioner let go or there was so much slack in the chain that it couldn't do it's job.  

Sorry to hear of your bad luck, Melena!  We'll keep our fingers crossed that it's nothing serious.

[Melena]

If it's the clutch splines/input shaft splines to the gearbox, you're dead in the water.Well, the bike runs, but when you shift gears you get no power to the wheel.  <clip>  There's usually symptoms just prior to the spline going as well.Hard shifting, etc.When his input shaft failed it went....ring-a-ding-a-ding-a ding-a ding (not like nuts & bolts in a food processor)

Melena, how many miles are on your bike?Per Leon Friday of Scooterville BMW, He "never had to replace a timing chain on a boxer motor."Unless the bike has 100k miles on it or more, Graham wouldn't even suspect the timing chain.IF it is the timing chain, then possibly the tensioner let go or there was so much slack in the chain that it couldn't do it's job.

Thanks Aïda.  
I didn't have any of that happen at all.  It was running it's very best.  I'd just had the carbs balanced and I haven't had it run so smooth before.  But, I was having an intermittent problem with starting.  I would push the starter and it would just go "rrrrr-rrr-rrr-rrr-rrr" and not start.  But would start the next time I tried it.  Of course it wouldn't do it when the mechanic tried it.  This is all it does now and won't start at all.  It was shifting just fine.  

The problem was sudden and not very loud at all.  It sounded like I got a chain or strap of some sort caught up in the wheels.  You know, like when you're riding a bicycle and the chain comes off.  But I hadn't run over anything and there wasn't anything there.  It was sudden and didn't last long.  There was a loss of power and I was on the side of the road within seconds.  Then it wouldn't start again.  

Oh, # of miles - around 45,000 to my best figuring.  

[Melena]

I ran out of words in the previous post.  

The bike is still in the trailer waiting for me to make some decisions.  I went and checked it out this morning and there is no oil under the bike at all.  I checked the oil to make sure there is oil in there, and it was just fine.  

I think I'm just going to take it to my mechanic as he works on these bikes and does an excellent job.  I don't have the room or the tools to take care of this problem no matter what.  I did a search on the forum about timing chains, which would be the easiest thing to fix, and I wouldn't want to try it myself    .  If it's anything worse than that I wouldn't do it myself either unless I had a garage and a year to work it out.  I'm up against time now as the riding season has started and I've got places to ride and rallys to attend.    

So, tomorrow it will go to the mechanic and I'll see what he has to say.  It should be pretty easy to see if it is the timing chain.  We will, of course, check all the other things too.

[ambrose78]

go "rrrrr-rrr-rrr-rrr-rrr" and not start

So to clarify it is currently doing this meaning  the engine is turning over?

And you were able to push the bike - clutch in or out?

What other vital signs of life does your bike have?

if your engine is turning over do have you got spark by any chance?

At a vague guess the noise you heard sounds vaguely reminiscent to the noise I heard when my bean can mashed the hall sensor to peices. With no spark bean can sensor it will crank till the battery is flat but it aint going to start.

That said it doesn't explain the difficult shifting....

Also what year is your bike?

[Rob Valdez 79 R65]

Good thoughts, Pete, especially the bean can (let it be so minor!).

But I do need to point out that Melena said to Aïda: "It was shifting just fine."  

And it's an '83 (signature).

[nhmaf]

When my clutch splines went, like Melena described - I initially had a hard time getting the transmission into neutral, as the engine could no longer spin the transmission to help with realignment of the gears if they weren't lined up just right (if you have a transmission out of a bike and test it by shifting gears up & down, you may often have to give a bit of a tweak to the input or output shaft to help the shifting process).   But, once I did get it to work after a bit more trying & rolling the bike foward in gear after having initially stopped it, it would shift into neutral, etc.   But, I tend to think this isn't Melena's situation as one could start the bike (it just made such gawdawful noise I didn't want to let it run as it was audibly chewing metal and I didn't want to worsen the damage).  

You mentioned that it just goes rrr-rrr-rrr without starting - I am wondering if the electric starter motor is running, but either the nose/bendix has somehow broken (it could be if it somehow engaged on a running engine @ 3500 RPM) or the starter gear's teeth are gone?   An easy test that requires no tools to tell if the engine is at least turning would be to pull the timing plug out of the case and look to see that the flywheel ring is turning as you crank the starter.   You could also try taking a valve cover off, pull the sparkplugs out, slip the transmission into 2nd or 3rd gear and roll the bike forward to observe the flywheel, valve/rockers and piston crown (through the sparkplug hole).   IF the rockers/valves don't move but the flywheel rotates and the piston crown is visible through the sparkplug hole, the timing chain is broken. If the piston doesn't move and the flywheel doesn't move, the clutch splines are gone.

It may not tell you any additional info, but it might help with the isolating the problem to the front or back part of the engine/drivetrain..  My fingers are crossed that it is simple and inexpensive!!!

[ambrose78]

And it's an '83 (signature).

well spotted  

[Rob Valdez 79 R65]

And it's an '83 (signature).

well spotted  

First place I look.  Then their name (like me).  Then I go to their profile, hoping for a hint there.

Everyone should have it in their signature so we don't have to wonder.


But my bike is coming out this year as even more of a frankenbike than it was before, with a '81 engine....

[Melena]

Oops!  I messed up on the  rrrr-rrrr-rrr sound when trying to start her up.  It just goes click-dnk.  Maybe an rrr click-dnk.   That's it.  I realized my mistake when it was tried by the mechanic and then I remembered that there is nothing turning over at all.  

Got the bike to him this morning.  He's pretty busy and will probably get to look into it tomorrow.  I told him the story and  he said his best guess is he doesn't know.  But, he says that the sound I described sounds like it might be a ...................... a sucked in valve.    

Oh, yeah.  That would make sense.  It does have the old valves in it.  I remember this discussion from long time ago - the old valves with the narrow stem and made for leaded gas.  So, if that's it, she's getting 2 new upgraded valves.    He's had enough experience fixing Airheads that he's got a good feeling for what could be wrong.  I'm just hoping that it's not too bad and didn't create more damage inside.

Too bad we didn't think about that yesterday.  Could have had the head covers off to take a look inside.  

But for now it's all speculation.  There's nothing like taking a look to see what's really going on.  

[Rob Valdez 79 R65]

I'll keep a good thought...  :-/

[ambrose78]

It just goes click-dnk

That would be the starter solenoids trying to turn an engine that won't turn. It really could be a lot of things.

here's hoping it is an easy fix. Fingers crossed.