570 engine rebuild help!

Hi guys, im new to this forum but very happy to have found a place for the Berg enthousiasts! I've always wanted to get a proper supermoto after driving mopeds and other types of motorcycles and now recently a nice 570 (I think FE converted to supermoto) has come on my path via a friend. It's a long story but I'll try to keep it short:
The bike had been bought by my friends brother a couple of years ago. He drove it for a short time after it started producing big amounts of white smoke. He then took the engine to the KTM specialist who fixed the problem, but when the engine returned and was in the bike again it had a loud ticking / knocking sound. I don't know why but he didn't return to the dealer but just let the bike sit and then my friend bought it from him to try and restore it. He did awesome thing like new tires powder coating a lot of parts and just make everything look pretty. He also disassembled the head but couldn't find anything really and put it back together with some new parts like a new timing chain and valve shims. Thats when I found out about him doing it, and I helped put it together with him but when we started it for the first time.... Still that stupid knock!

Fast forward to where I'm at now, after starting it I disassembled the engine again because of the sound and I found small metal shavings in the oil. The engine is now fully apart and I just havent found anything that could produce a sound like that. I will throw in some pictures and maybe a video if I find out how to do that.

To sum up what I found: (TLDR)

- 570 engine with knocking sound (doesn't sound like chain tick I think and I've tested 3 different spanners even a hand adjustment one but didn't do anything)
- The head seems resurfaced, but there seems to be a small bit of the intake valves also got sanded
- Chain looks good there is slight signs of damage to the canal where the chain lies in (like it has been too loose) but that might have been an older problem and doesn't look too serious)
- Top of the piston has some damage, but just really small and doesn't look like it could produce a hard tick
- slight scoring of the cilinder walls but you almost can't feel them. The piston felt a little loose in the cilinder.
- Main bearings from the crankshaft look very good too
- Big end of the crankshaft has too much play sideways

I would love to hear your opinion on this and, should I replace piston + cilinder and all the casing bearings + main bearings of the crank? "While your in there"? Or is it a waste of money?

Thank you very much for your insight beforehand!

I made a YouTube video with al the footage of the sound and damaged components:



Regards,
An enthousiast who is hoping to learn something

jojo09 said:

Sounds like a failing conrod.
The axial play of the rod also hints that way (it looked like it tilted on the video)
Go and press the pin out (if you don´t have the possibility find a shop that does).

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Thank you so much for the reply these words are already really helpful. I’m going to press out the conrod pin and check for damage. The piston pin also looks pretty worn, I can feel some damage. What you said about the piston, maybe better to just get a new piston + cilinder then
Also, could I have your opinion on the valves that look like they were grinded with resurfacing the head? Small flat spots on the ends near de flat mating surface.
Thanks again!!

Taffy said:

the way to check the rod is first of all to measure the width of the crankshaft. It should be I believe 64.00mm

Secondly, the side float should only be around 0.45mm. hold the undeneath of the rod still against the crankshaft wall and try and wobble the little end end of the rod. This is a more accurate way of diagnosing wear.

Taffy

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Thank you Taffy. I already measured the crank and that was good. I believe it was right on but I will re-measure. I forgot my feeler gauges that day so I will measure that too. Will keep you guys posted