overheated and now have knocking noise

embarrassed to say but I let the oil get low. it over heated and now there is a loud noise from the engine...I am sure could be million one things that it could be but figure I would post and ask....
The bike runs after oil change but afraid to ride it because of the loud knocking noise....

you have to ride it sometime to check it out!

Thanks -

Anything specific I should be looking for?

You might want to introduce yourself and tell us what the bike is.

These old Kz 4 cylinder motors are pretty tough and i remember watching a video where a guy ran one without any oil and he had the engine redlined for about 10 minutes before it finally let go.

I would suggest starting the bike and letting it idle so that can you pinpoint where the knocking is coming from...either from the top end or down below from the crankcase area. This will give you an idea of what potential issues you are dealing with.

Cheers

Sorry -

Hi - I have a 1980 KZ550 LTD that embarrassingly I let the oil get too low and it over heated.
I did an oil and filter change and It now starts with a rattle/knocking noise but afraid to run it.

Thanks

Attached a bigger picture of the bike

How low did you let it go?
Is the knock coming from up high or down low?

Remove your oil pan/ sump from the bottom of the engine. Inspect for signs of bearing failure, look close at findings in there. Also inspect the big end of the connecting rods where they go on the crank, see if they look like they got hot. See if there is any excessive play, at the rod to crank big end bearing.

PLUMMEN wrote: How low did you let it go?
Is the knock coming from up high or down low?

It leaks oil and one day rushing off to work forgot to double check oil levels.
I now have a complete gasket kit for the engine. In the next month or two will pull it out of the frame and replace all the gaskets....

Mean time trying to gather all info I can to know what to look for when I have it pulled apart. Will go over where I have it parked to determine if it is high or low and post back what I find....

studysession wrote: embarrassed to say but I let the oil get low. it over heated and now there is a loud noise from the engine...I am sure could be million one things that it could be but figure I would post and ask....
The bike runs after oil change but afraid to ride it because of the loud knocking noise....

Did the engine oil warning light come on at the time, while the engine was running?

Normally, when the bike is off & you turn the ignition switch to ON, the oil warning light should come on & stay on until you start the bike, then it should go off after you start the bike. Just making sure you know what the warning light is supposed to do. (assuming your 550 has the warning light -- reference the owner's manual).

There are some knowledgeable guys around here, so I would do what Motor Head suggested --- drain the oil, pull the oil pan, & take a look. After draining the oil, maybe put it on the side stand so that you can get a better view. A good light & mirror would be handy as well, There might be a youtube video or two that might be helpful for comparative purposes. While the oil pan is off, that would be a good time to clean the oil pump screen n stuff.

studysession wrote: embarrassed to say but I let the oil get low. it over heated and now there is a loud noise from the engine...I am sure could be million one things that it could be but figure I would post and ask....
The bike runs after oil change but afraid to ride it because of the loud knocking noise....

Low oil, knocking sound? You don't say how low or how you figured out it "overheated".

My first guess would be a rod bearing failed.

I bought a ZX12R that fell over on it's side while parked and idling. It ran for no more than 3 minutes and spun two rod bearings. The only noise was a tapping coming from the head, caused by the pistons on the two rods that spun rod bearings hitting the head. Wouldn't think a noise coming from the top end would be caused by a bad bottom end, would you

Buy a used motor, and rebuild the one you have over time, as you find the parts.