Tuning nightmare

[shade]

Had to pick the bike up from old tuner. Just couldn't get it done. I think he was in way over his head.
Take it to new tuner and bike struggles working through the rpms
Tuner shuts it down and a piece of metal pops out the exhaust..
Piece of the piston crown broke off.(turbo piston)
Tuner pulled the engine and tore it down.
Piston obviously needs to be replaced but no damage to the cylinder or head in any way. Going to replace a valve but how strange no damage to anything else.
So bummed but piston and valve should be in end of week. Replace and finish tuning.

 

[ItsDooomz]

Double check those ring end gaps

 

[shade]

Double check those ring end gaps

Will do. Going to run down there today and snap some pictures.

 

[Dnyce]

wow so a piece of the piston broke, came out the exhaust, and didn’t mess up the turbo, the head, the cylinder walls, nothing? Go buy a lotto ticket lol that’s luck

 

[shade]

Cylinder wall a little scuffed. The rest look good.
Going to hone all cylinders and be good.
Bent a valve so will polish the combustion chamber but no damage elsewhere, thankfully.

 

[Dnyce]

That’s a big chunk too lol luckyyyyyyyyy

 

[shade]

That’s a big chunk too lol luckyyyyyyyyy

What came out was lots of little tiny fireballs. Not 1 huge chunk.

 

[Busa Quick]

Recommended reading for piston ring gap can be found on this page. Wossner Pistons. I have found similar information on other websites as well if you want to take a second opinion. Everything I've studied says that when a piston breaks like yours did, it is because the ring gap was too tight and when the ring got hot it expanded until it jammed in the bore and the piston is the first thing to go

 

[Busa Quick]

And I can tell you that when you buy a set of Wossner Pistons, you better check the ring gap because it is most likely going to be too tight. Nothing against the Pistons whatsoever as they were a great product that I bought, but you have to do your do diligence.

 

[shade]

Hey Busa,

The rings on the other pistons are gapped perfect. They were checked today.
The rings don't come pregapped, my builder had to file them down to spec. While I'm not doubting your information, evidence with the other pistons is the rings were set right, but who knows.

 

[202mphbusa]

Hey Busa, The rings on the other pistons are gapped perfect. They were checked today. The rings don't come pregapped, my builder had to file them down to spec. While I'm not doubting your information, evidence with the other pistons is the rings were set right, but who knows.

I would know, No one Builds my poop but me so I could open my note Book and look

 

[shade]

Hey 202, I'm always willing to listen so of you also believe ring gap, cool.
At this point then the new piston will be gapped correctly. One thing I did ask the new guy is to make sure the injectors are flowing correctly before putting it all back together.

 

[Busa Quick]

Hey 202, I'm always willing to listen so of you also believe ring gap, cool.
At this point then the new piston will be gapped correctly. One thing I did ask the new guy is to make sure the injectors are flowing correctly before putting it all back together.

Definitely wish for you to have success, it's awesome that you are getting involved in your build! I also appreciate the sharing of information so that we can all learn.

 

[sixpack577]

It looks like it was 10 seconds from being a boat anchor.
Great save.
Good luck on the rebuild.

 

[Dnyce]

What were they gapped to?

 

[sixpack577]

And I can tell you that when you buy a set of Wossner Pistons, you better check the ring gap because it is most likely going to be too tight. Nothing against the Pistons whatsoever as they were a great product that I bought, but you have to do your do diligence.

They usually come with the end-gap too small, that's normal.
It's easier to manufacture that way, especially since the gap needs opened/filed anyway.

 

[shade]

What were they gapped to?

Im going from memory of a conversation with Richard from RCC turbo. I believe he recommends .018 - we went with whatever he recommended

 

[Dnyce]

If the other rings don’t lay flat now, they probably touched and need to be replaced as well even tho they did no damage.

Since u got it apart, check the gap now and see if it’s still 18. Even the best ppl can flub something, rechecking don’t hurt and it’s free -u don’t want it to look like this after the first dyno pull lol

Btw pretty sure u can go to 20-22 with no ill effects according to some fast pro street ppl.

 

[bigoltool]

The gaps called out on the Wossner Website at first blush seem crazy tight, but i'm no tuner.

Stock Gen 1 Suzuki had both at .020" per the manual.

 

[shade]

If the other rings don’t lay flat now, they probably touched and need to be replaced as well even tho they did no damage.

Since u got it apart, check the gap now and see if it’s still 18. Even the best ppl can flub something, rechecking don’t hurt and it’s free -u don’t want it to look like this after the first dyno pull lol

View attachment 1650217

Btw pretty sure u can go to 20-22 with no ill effects according to some fast pro street ppl.

Builder said all other gaps were perfect, they measured. - I did not ask what the gap amount was but will try. I did see the jugs while I went down there a couple days ago. All cylinders looked great even the one with the messed up piston. It just needs a quick hone and all set.