So I gave the bike an oil change this weekend and when I did, the head of an allen bolt fell out.  What's really weird is that it looks like the head was chewed off from the back.  The top of the bolt is unscarred. In fact, when I first saw it, I thought it was a spacer, but when I flipped it over I saw all the score marks.

Now I've gone threw the Hayne's manual looking for where this bolt could have come from.  I'm not sure if it came out the center drain or the filter compartment.  It was closer to the filter compartment side of the drain pan.  But the only allen head bolts I could find are in the starter clutch.

Anyway, I looked around the inside of the oil filter area and couldn't see anything awry.  The bike ran fine up until the change, now I'm too scared to start it.

Any advice or suggestions would be greatly appreciated.

And I know I should have got pics of the bolt head, but it seems to have disappeared now.

The only likely place something can get ground down and not destroy the engine most likely is a starter clutch bolt.
Too bad it is lost.
You might need to remove the left cover and check the starter. Since there is ground down metal, if the starter, the metal is probably on the magneto.
You can clean the magneto and use duct tape to remove the metal bits.

Interesting - I just realized that they sell drain plugs with a magnet. But the magneto would attract all metal bits before they would get to a drain plug with a magnet. Maybe the drain plug would get a little, but most would go to the magneto. There''s another bling thing we don't need to waste out money on!

Arent the two big bolts inside the oil pan that help hold the two cases together allen (socket) heads?

Quote from: weedahoe on March 05, 2013, 03:34:07 PM
Arent the two big bolts inside the oil pan that help hold the two cases together allen (socket) heads?

Maybe - but there is nothing in there to grind it off. if it was and fell in the sump, it can't get out due to the sump filter and the oil pump can't shove a bolt through it to get anywhere to grind it down.

Quote from: adidasguy on March 05, 2013, 01:21:40 PM

Interesting - I just realized that they sell drain plugs with a magnet. But the magneto would attract all metal bits before they would get to a drain plug with a magnet. Maybe the drain plug would get a little, but most would go to the magneto. There''s another bling thing we don't need to waste out money on!

Hey, Ive got one of them installed

can we get a picture or 2 of the said bolt in question please.

Quote from: wayne242 on March 05, 2013, 06:14:13 PM
can we get a picture or 2 of the said bolt in question please.

Unfortunately, no.  I put it somewhere safe where I wouldn't get it mixed up with the other stuff while I'm working on my Hyundai and my Jeep...long story.

Anyway, now that it's nice and safe, the best I can do is describe it....

It was bronze in color, smooth outside, no grooves or nicks at all.  The face was slightly indented with a hexagonal hole in the center.  I really thought it was an insert.

Then I flipped it over, it was completely flat, but you could see scores where it looked like someone had taken a hacksaw to it and cut it off.  That's when I started thinking, "Crap! It's the head of a bolt that got chewed off."  I opened up the Haynes manual hoping to see an easy to access bolt or dowel that fit the bill.  When I got to the starter clutch, the piece I saw drop out looked a hell of a lot like one of the three bolts that mount up the starter clutch to the rotor like the picture.

[attachment deleted by admin]

I was cleaning up my tools and found the little bastage that fell out.  Looking at it again, it still strikes me as a spacer.  I got the bolt I thought it was, and it's definitely not that.  Much to thin of a wall.

Gasket is on it's way so I can crack the cover off, but still not sure what to even look for.

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Looked a lot like a socket to me or what's left of one.

Does an allen wrench fit? What size?

dont matter .. just a query .. is an Allen .. a wrench?... or a key? ... have heard both used .. but 

Quote from: wayne242 on March 10, 2013, 06:49:00 PM
Looked a lot like a socket to me or what's left of one.

Think you might be right.  Hadn't even thought of that, but it's almost identical to the end of my 1/4" socket.

And a 6mm allen wrench fits, but it's just a hair loose.

Question now is, what's the best approach to finding the rest of it?

Quote from: Janx101 on March 10, 2013, 08:50:22 PM
dont matter .. just a query .. is an Allen .. a wrench?... or a key? ... have heard both used .. but 

Allen is the guy down the street


Sure does look like the remnants of a socket head. Most likely there is none of that in there. probably someone dropped it in working on the engine or it stuck to the magnets in the magneto before getting destroyed.

I think not as bad as we all thought. It could have been in there since the bike was made and just now fell out. If bike sounds OK starting it, I would not worry much.

Still not a bad idea to open the sides and have a look see.

The tool steel in a socket is really hard stuff. Little concerned it might be the head on one of the crankshaft bearing bolts. Those are one of the few big allen heads on the inside of the engine.

You can inspect them the next time you change the filter. I'd just feel with a finger to make sure they are still in place. They are accessible from inside the oil filter cavity, and also accessible by removing the oil pan.

The big-ends use skirted nuts and studs.........so its not come off there 

Never seen a socket cap-head bolt with so little wall thickness and a top face that is not flat and most socket cap heads are high tensile and coloured black, that looks to be polished or chrome plated.

Definately looks like the remenent of a socket IMHO and if 6mm hex key is a slack fit it was probably a 1/4" AF.

Its out of the engine now and not going to do any harm so the next question that needs to be asked is.........where is the rest of it??   

The two center crankshaft bolts are 6mm Allen bolts. Had a case apart recently, just practice.  As burning1 mentioned they are accessable from filter housing. Check, reuse gasket and filter if you have not started the bike yet.