What the heck happened to my engine

[dz]

Well, I just picked up a lt125 for $125, put about $70 in parts to get it running right. After riding a few hours, while my friend was on it, i was not really near him at the time, I kinda heard a squeally noise or something and I instantly ran over to where he was. He said it was running when he shut it off, he shut it off obviously because it made the horrible noise. Now heres the good part. The engine does not run, it still has great spark, still has the same amount of compression it had when I had it dialed in, still getting gas. Now I noticed that it did burn a little oil which was probably due to the rings being weezed out when it was running. Now when you pull it, after the power/compression stroke the top end makes a combination of a click and clunk noise. The bottom end does not seem to be loose. What really gets me is that it still has great compression and spark. If any part of the bottom end went it would be harder if able to be pull started at all. I am going to tear the top off tomm., does anybody have any suggestions as to what might be wrong. Thanks.

[hondaATCman]

Probably something in the valvetrain.

[Howdy]

Sounds like the main rod bearing went bad. Most noises are not a good thing. Squeels are even worse.
Howdy

[dz]

Update: It only makes the clicking sound when the valves are moving. I took the head off and spun the engine and it sounds normal. There are scrape marks right above the cam shaft gear, on the head itself, at one point it looks like the chain jumped and hit the top of the engine (probably the squeely noise) and now the valves are probably scrap. If it were a low end bearing it would feel loose, it still feels tight and has compression. The cam chain feels loose. If anybody has a head let me know. Thanks for the input.

[Howdy]

Update: It only makes the clicking sound when the valves are moving. I took the head off and spun the engine and it sounds normal. There are scrape marks right above the cam shaft gear, on the head itself, at one point it looks like the chain jumped and hit the top of the engine (probably the squeely noise) and now the valves are probably scrap. If it were a low end bearing it would feel loose, it still feels tight and has compression. The cam chain feels loose. If anybody has a head let me know. Thanks for the input.

I would inspect the top end and also the rod bearing real good before buying parts. I'm not saying your wrong or anything. But I still think the rod bearing could be bad. Also, I would hate to see you buy parts you don't need.

Parts: We have a bunch of LT125 parts scheduled to go on Ebay in 3-4 weeks. I also have some LT185 parts kicking around. If you need the parts sooner I can try to bump the schedule up some. I can sell some stuff before listing, but I prefer to sell it on Ebay. Why? Because once a item is listed the buyer has 7 days to make up their mind if they want it. And the bidders set the final price for it.
Howdy