maybe this is the cause of my issues? OMG

[husley]

Took the 50hr bike's top end off to adjust squish as I'm having an issue with poor low-end and slow to increase RPMs (posted in a different thread about this).

09 200
50 hrs
Motul and Maxima 44:1

Found this today.

[john r b]

Interesting find. Are you a high rev r. ? I've wrung my 200's neck quite a few times

[husley]

Originally Posted by john r b

Interesting find. Are you a high rev r. ? I've wrung my 200's neck quite a few times

No! Quite the opposite. I am low-rpm/bogger riding 2nd gear single track. I doubt I have hit the rev limiter once.

Could this explain the complete lack of low-end and a slow to increase RPM/Rev when in neutral/clutch engaged?

I believe the cylinder is fine

[twowheels]

That should buff out

[TheLetterJ]

Yikes! I'd definitely have that cylinder measured for out of round or taper. What size is your piston (A, B, C) and does it match your cylinder?

[husley]

Originally Posted by TheLetterJ

Yikes! I'd definitely have that cylinder measured for out of round or taper. What size is your piston (A, B, C) and does it match your cylinder?

Great questions that I do not yet have an answer for. I'm taking it to the local GG Dealer to look at.

What is "out of round" and "taper" ?

[Jacob 'Berg]

Ouch, you definitely had some skirt slap happening there...You are lucky it did not grenade.

[husley]

The crack goes almost all the way across. Begins at about 2'oclock and continues across to 10 o'clock

Manufacturing defect?

Where is the missing material (material missing where cracks are dark on the edges of piston)

[(F5)]

My 200 piston was a wiseco and replaced with the same. Came out pristine.

Let's talk about airfilters as something is getting in there. The hiFlo and Twin-air seem good brands. Use real filter oil, not the pretend NoToil(not oil) stuff. Smear of grease on the mating surface and a careful check to feel if the filter is actually seated, not hung up which is easy to do.

Do get them to measure barrel. In the old days where steel liners wore a sloppy barrel would break piston skirts. I doubt with plated liner this could ever be a problem but might as well check in case there is some damage to shape of bore before it was plated.

[Zman]

You caught that just in time. If it cracked off you would have had a expensive repair. I would expect that engine rattled like crazy.