Top of piston nicked
 

Hey all,

I am building a BP4W to replace my 1.6, I was planning on Eagle rods with stock pistons. When I was cleaning up my pistons I notice there was some scratches/nicks on the top of one piston, the rest are perfect. It is not deeper then the markings, and does not go onto the sides.

I was just wondering if this is good to use, first time building my own engine so not sure if this will cause any issues down the line.

Thanks for the help!

https://imgur.com/a/LaUA7Er

Broken TB much?

Skunk2 TB FTW, also known for good reason as Junk2, but the fixes are easy and you will never have to worry about swallowing another TB screw. Search on here for the fixes.

Engine was from a junkyard so not sure if the TB broke at some point and was replaced, but both screws are intact now.

I want to check the head now but it is still at the machine shop...

OK, now check both sides of the screws. If that checks out you are probably correct, but it might also have been run without an aircleaner too, so who knows what actually caused the marks. I have no expertise beyond recognising screw indentation when I see it, and TBH that does not look like a screw mark to me. Replacing the stock TB on a hard used MX5 is a good idea regardless of what caused it.

Yeah both sides are in tact, the motor had a spun rod bearing if that's of any significance.

Would you recommend getting a new piston or do you think it is ok to run? The marks aren't any deeper then the factory markings, so not sure if hotspots or something else would be significant or not.

Thanks again for the help!