Need some help with RM125

[Mattster]

Hey all I'm new here and am looking for some advice on what the problem may be with my bike.
I have a 1992 RM125. I was out yesterday for a ride, while riding, outta the blue I heard this ratteling noise. I stopped and with it running it sounded like a rock or something ratteling around inside where you put the oil on the right side of the bike. I babied the bike back to the truck, by the time I got back it sounded kinda muffled and died out comepletely. I kicked it a few times to see if it would fire back up but would not even pop or come close to starting. Any ideas what may be the problem or what to look for when I get it apart? My only guess is a bearing or something went in it.
Any help is appreciated.
Thanks

 

[minutz]

Rattling sounds are never good, I'd drain the coolant and pop the head and cylinder off, you will be able see whats up. Its pretty easy just disconect the powervalve rod and a few nuts and your there.

 

[Mattster]

Is there like a Haynes manual or some sort of repair book for these bikes?

 

[_JOE_]

Suzuki and Clymer should have service manuals for you.

 

[Mattster]

So I pulled the clutch cover off on the right side of the bike where the oil goes in. Inside there's the five bolts that holds in the springs and most of it together. One of the five bolts looked like it was kinda loose the head was ground down and basically mushroomed it. I'm thinking the previous owner didn't tighten the bolts properly. The oil was also filled with metal filings. I couldn't see any pieces or any real damage to anything. I guess next step is still to pull the head off and see if there's any damage in there.

 

[whenfoxforks-ruled]

Look inside the clutch cover. And be real careful tightening them bolts back up on your pressure plate, them posts break off real easy!

 

[Mattster]

I did look in the cover, thats what I stated in the post above. Where I found metal filings and one bolt with the head ground. whats weird is in the inside of the actual cover there is no marks of any kind. I'm going to put it back together and see if it'll fire up.

 

[whenfoxforks-ruled]

They must have replaced the cover? I would get some cheap oil and fill it, drain it, fill it, start it till the jug is warm, and drain it. See how much shavings are left. Is the inner hub post broke where its loose, stripped out?

 

[Mattster]

We put the clutch back together and put the covers back on. Tried to start it and not even close to indication that it wants to start. I may have to take it to a shop for some diagnosis.

 

[sr5bidder]

you should check the flywheel sounds like it came loose.. pop the flywheel cover off and take a look..

 

[Mattster]

Ok so I found the problem today. I pulled the cylinder off and found that on the front of the cylinder/head right by where the exhaust pipe goes in, there was a little cover held on with four phillips screws. I pulled that off and one of the exhaust valves or spacers whatever it is was completely broken and had jammed the pin that goes through them, stopping anything from moving in there. Are these valves replaceable? or should I just source out a new head and be done with it? I'm going to replace the piston as well, does anyone know the size?
Thanks for the help guys

 

[whenfoxforks-ruled]

20~500 hundred bucks in parts from the online dealer. http://www.bikebandit.com/showschematic/m6564sch279232 . When the parts get up to 150 I would be looking for a used cylinder complete, or just the exhaust valve complete. Did it nick/damage the bore, port edges, or head?

 

[Mattster]

Thanks for the link!
There is some slight vertical grooves in the inside of the cylinder. No knicks and the grooves are very fine, to the point where you can't even really feel them with your finger or nail. I've been searching like mad for a used complete cylinder, no luck. Anybody know where I can find one?