Chain Guide Failure

Hey,
I've had the 'stuck in first gear' problem. Got out the broken piece of the chain guide.
I have now removed the engine. Have it on the bench upside down and found These Pieces inside.
Anyone know what they are and what it means now?
It looks like i'm gonna need major work on my Engine now.
Local mechanic says if i take the engine to him it's gonna cost at least £200 GBP plus parts before i found the bits in the sump)
(And that was b
Boo!
Any guidance much appreciated folks
Nick

 

Anyone got any ideas please?
I need to get this baby back on the road.
Thanks in advance
Nick

 

pic's not super clear... are they metal, and how big? They almost look like they could be pieces of (I don't want to say this) a piston skirt?

 

Thanks for the reply fitz.
Yes they are metal and they form part of a cylindrical shape and are shamfered on the inside. But i can't see anywhere that the pieces might have come from. As all i can see are cogs, gears and chain in there.
Nick

 

Could you please give us an idea of scale? Shoot the photo with a ruler or a #2 pencil next to the remains to help with this.

 

Ah ok, yeah i should've done that.
I reckon it would be about 1.5 to 2" (inches) in diameter (if you had all the pieces and put them together) as the pieces are curved.
I have to say tho' that these parts didn't stop me changing through all the gears once i'd gotten out the piece of primary chain guide a few weeks back.
I haven't been able to ride it (other than about 100 yards to test the gear change) coz i didn't want to risk anything.
I'm wondering how long they've been in there coz i've had absolutely no problems with noises or anything until the gear sticking and even that was when i went to leave for work one morning. Weird.
I'm wondering about the PO!

 

Metric references are easier for me but I'll run with it, you have the remains of a cam bucket skirt sitting there (that is what it looks like to me). You need to open up your valve train and pull buckets.

 

Thanks Robert, sounds like you're speaking foreign language to me LOL.
Are they expensive to do? Can they be replaced easily?
Thanks for all the replies guys.
I'm worried about this and sort of excited at the same time.
I ALWAYS lose small bits when i take anything apart and i don't have a garage. ah well! These things are sent to try us.
Nick

 

Take off the top cover (valve cover) and you will see the cams and the buckets.

I am assuming you took the sump cover off and found these? If so I'm not sure how the cam bucket can get down there, I would think it would fall into the cylinder? Although from the size I have to agree with Robert that it could very well be a bucket.

 

Cam buckets are HARDENED and even if one did break, how would the pieces get down into the sump? They would be trapped. I still vote piston skirt remember the pistons are only about 2 1/2" in diameter (63mm.)

 

True Fitz, they are hardened. I can see (in my minds eye) the piston skirt section you are referring to but the 2 inch circumference estimation really narrows it down, don't you think? I do hope Nik can get us a better picture (hint hint).

 

Thanks chaps, i'm on it. Tried to upload a new pic yesterday but couldn't. Trying again now.

 

Ok, managed to upload another...let me know if this is clearer for you. It's Here

 

Broken cylinder sleeve!
Better take that top end off.

 

yup looks like the bottom of the sleeve to me too. still has cross hatch on it.

 

Oh, man, the pic says it all. Sorry to say they're right. That's the bottom of a cylinder sleeve, the part that fits down into the crankcase. It's chamfered like that to aid in piston installation (you're holding it upside down in your pic.)

How the heck it got broken like that is anybody's guess but I'll bet the PO knew and didn't share...

The only time I've personally seen that bit broken was in motor that had suffered a broken rod.

Could a chunk of chain guide gone for a "ride" on the crank cheek and done that? (Thinking out loud here)

What's REALLY gonna suck is if you pull the cylinders and the bottoms of all of them are fine, meaning it was debris from a former disaster.

You're going to HAVE to pull it down and look or risk exploding it if you do have a cracked liner. Sorry.

 

Well chaps, thanks for all your responses, it's much appreciated.
I have the engine on a table outside and it's due to go to the local Yamaha dealers (where the mechanic is a friend of a friend).
He's agreed to do the chain guide (hasn't seen the engine yet) but he has worked on Yamaha engines for 30 years, so hopefully he will be able to sort me out.
I am a bit worried about the cylinder issue tho'.
Oh well, just want to get back on the road, driving the car every day sucks!

 

I'll confirm the cylinder sleeve. The size (thanks for the thumb) and the cross hatching is a dead give-a-way. Pull the motor, you might have more damage than you think. I'd be pulling the lower end caps to inspect bearings!!!

 

Robert,
Thanks for the reply.
Ok, I have been looking for a picture or spare part of the 'cylinder sleeve' anyone know where i can find it and what the part number is? I can't seem to find it anywhere?
Going this far into the engine is out of my league so i'm going to get a mechanic to look at it for me and i'd rather know what parts i'm going to need to get.
Thanks again.
Nick

 

I'm sorry but the cylinder bank is a one piece assembly. I'm not aware of what can be done to salvage yours if the worst case comes to pass.
You could get lucky and not need to do a thing to it (if the chunks are low enough on the cylinder wall). I'd have a competent shop look it over for possible weaknesses and advise you on salvage. It may be you need to replace the entire assembly.

 

Ok, what sort of assembly would i be looking for something like this

 

Nope, that is the cylinder HEAD, you need the piece that goes below the head, but on top of the crankcase, which are the JUGS..........

 

Chacal, are the jugs even available as new old stock now? Any idea what the cost would be? This repair, if it is as it would appear is likely going to need start with a donor bike isn't it?

 

No, but the jugs shouldn't be that hard to find, although if he can't locate any over there (UK), then it might get very expensive to ship them to him from over here.......

 

so what i'm hearing from most of you is that these bikes can't be re-sleeved.
why not? i'm sure you could find a machine shop capable of re-sleeving it if you can find the right sleeve. and i'm sure any good machine shop could find you said sleeve. at my local shop i bet i could get all four done for a few hundred bucks. that's what they do.

 

These jugs are probably not sleeved. My bet is they are cast and then bored to spec. They aren't built like diesel engines where they press the old sleeve out and replace the sleeve and piston.

 

they have to be sleeved. the block is aluminum and you can't have an aluminum cylinder wall. all aluminum blocks even cars are sleeved. i just rebuilt a xs650 and it was sleeved. otherwise he wouldn't have broken pieces of SLEEVE. i say find yourself either a parts bike or a good machine shop.

 

They're sleeved, holding a grubby little set in my hands right now........

Very thin sleeve, but sleeved nonetheless...........

 

Chacal, aren't the jugs cast steel/iron and not aluminum? If not then the broken pieces would either have to be the bottom of the sleeves or aluminum. What is in the pictures is way to brittle to be aluminum. My best guess is that the broken parts are cast iron or steel

 

The heads, jugs, and crankcases are aluminum....I believe the oil pan, at least on some models, is actually magnesium!......and each cylinder bore has a thin iron "sleeve" about 1.5mm thick that is actually the "cylinder". These sleeves extend below the plane of the lower edge of the finner jugs, and are the round "tubes" that you see if you ever take the jugs off of the crankcase.

And yes, the broken pieces most probably came from the very lower edge of one of these sleeves, and raises the more imporant issue of why? and what? hit the bottom of the sleeve to cause it to fracture like that. Like Fitz says, you typically see that kind of damage on a sleeve when a rod goes dancing through the guts of the engine before it "exits stage left" through the block.........

 

Heavens to Mergatroid!

 

Hmm, interesting guys. Thanks for your thought and comments.
I will keep you updated as to what is found when it's been stripped down.
Nick

 

Right then, things have moved on!
I found someone on Fleabay that was trying to sell a complete Seca 650 that was 90% restored. I noticed that he was selling parts, so i guessed he was 'breaking' it. I contacted him and sure enough he was willing to sell me the engine and loads of spares. The engine has been completely restored including very nice looking paint job. Only thing is, its about 3/4 assembled and the rest is in boxes (All the parts are there including new seals, gaskets etc all purchase from the Yamaha dealer) He has obvioulsy spent a large amount of money. I've no idea how much work is involved in completing the work. It needs the 'final drive' installing the head re-attaching and the shims doing. (I'm not too sure at all if i can do that sort of stuff).
Anyway, thought i'd keep you updated..
I will post pics of what i got for my £200...

 

It sounds like you got "a deal"!

 

Ok chaps,
Here's the goodies that i bought for my £200.
I think i got a good deal.
Just gotta get it all back together (wish some of you experts were nearer) there's no-one near me anywhere that i know of.
Still, it'll be so worth it when it's finished.

 

Those are some really beautiful boxes.........

 

Looks like you got a great deal.

 

Just FYI, stock cylinder liners can be removed by placing the block in an oven heated to about 400F (might need to research that a little). Invert the block so the top is facing down and the liner should slide right out. Stock cylinder liners for an XJ650 motor can be found here.

http://www.cyclewareables.com/pages/str ... leeves.htm