FS570-Mechanic Screwed Up or Bad Luck?

Hate to start my introduction to these forums this way, but hello!

This is a doozy, but I'll try to make it as brief as possible.

Back in August 2022 I took my 11' FS570 out for a quick mountain rip. About 5 miles in she dies. I assume the common injector or fuel pump. At this time I was in the middle of moving and didn't have the space to tear into it myself, so I took it to a shop. A well known engine shop who's name I'll withhold until this whole thing unravels.

I tell them I suspect a fuel pump or injector issue, but the bike has 400 hours so while it's here let's go ahead and do a top end, valves, etc. and inspect the bottom.

Fast forward to January after months of back and forth. They do injector cleaning, new OEM fuel pump and can't get it to start. They also did the top end, say the bottom feels great and aside from a little low compression the top looked great also. "Keep doing whatever maintenance you're doing because it looks great".

Tell me the FI light is saying "injector" and the only other option is to start throwing non-refundable electronics at it. At this point I tell them I'll just come get it and do my own diagnosis because I'm settled into my new place and have my shop setup to do it. I start at the fuel pump. We have fuel pressure, interesting. Go to the injector....um...it's not even plugged up to power?

Finding that gave me a bit of anxiety. I fire it up and my god it’s knocking horribly. I take this video and shut it down. Send it to the mechanic and they ask me to bring it back.

Well, after a few days I get this photo and a phone call from the mechanic. His explanation is that the crank has went bad causing the piston to hit the head (pointing out the ring around the crown of the piston). He offers to do the bottom and get everything fixed for another $2k. I say absolutely not, but the bike in boxes.

I’m going to pick it up today. I guess the point of my post is to say, is it possible that on a few top end it strained the crank enough to cause failure immediately on it’s first start up? I don’t build engines for a living, but I could have done this myself and saved myself 7 months of frustration and $1,700 for nothing but it to leave worse than it came into their shop.

I still don’t trust that they didn’t do something incorrectly. What are some things to check and look for when I pick it up today other than the obvious?

I think I’ve cracked the code.

Picked it up today, disassembled. Start putting the head and stuff together. I’m missing my head gasket. Now when you look up gasket kits, it lists several different KTM models 530, 400, and the 570. The problem there is that those other models have a 95mm bore where the 570 has a 100mm bore. If they used one of those gaskets, it would’ve had 2.5mm of metal gasket ring hanging into the bore.

If you looked at that photo that’s about exactly what’s showing around the top of the piston. No markings at all on the head despite their claim that the crank was bad causing it to strike the head. The crank also doesn’t have any “feel-able” up and down play, just side to side.

Another interesting bit. I wanted a printed itemized invoice. They “upgraded” their systems and will have to have their computer guy send it Monday. Aka build one that shows the right gasket.

Someone tell me I’m not crazy before I get really stern with this shop about refunds.

StevenD said:

First post as well after builing a 570 over the past weeks. I dont trust shops, confirmed again by your story..

This by the sound in your vid could also be caused by a bad or wrongly installed cam chain tensioner. Sounds a lot like the camchain slapping. A piston kissing the head or gasket is not going to give you that pitch (or damage). Could well be that gasket was wrong as well, causing the 'ring' on top of the piston, but I doubt that would be more then cosmetical at that RPM.
Would be interesting to check the height in the bore to confirm this. If it was actually hitting up to that audible point, I would not trust the crank bearings anymore :-(

Click to expand...

So to update, I called cometic and ordered a 100mm head gasket. Reassembled everything and the bike fired right up and sounds great.

To recap, the shop installed the 95mm head gasket and tried telling me it needed a $2k crank rebuild. They also hid the thrashed head gasket from me when giving me my parts back.