seized piston EC 300 2018

[eralha]

Hi guys did the first top end on the gasgas after 100h the piston and cilinder was like this:

I didnt notice this happening, the bike had so much torque whit this, could not even imagine this. Is it ok to put a new piston on this cylinder?

thx.

 

[memphis2857]

Can you feel the marks with your fingernail? Hard to tell with pictures but, it looks like it may clean up.


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[eralha]

Can you feel the marks with your fingernail? Hard to tell with pictures but, it looks like it may clean up.


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On The piston The i can feeling The marks on The cylinder i almost cant feel it.

 

[RudolfHucker]

Sometimes, the marks on the cylinder are just the anti friction coating from the piston. You may be able to carefully polish this off the cylinder with a scotchbrite pad.

The Nickasil cylinder plating is rock hard so you won't damage it with a scotchbrite but don't be tempted to use a cylinder hone.

 

[eralha]

Can you feel the marks with your fingernail? Hard to tell with pictures but, it looks like it may clean up.


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On The piston i can feel The marks on The cylinder i almost cant feel it.

 

[memphis2857]

I would try to clean it up with scotch brite. In the photos you can still see the cross hatching under the scaring. I wouldn’t be afraid to put a piston in it and run it after cleaning the cylinder up a bit. Remember though, this is only an opinion based on pictures.


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[Davehuge]

Sometimes, the marks on the cylinder are just the anti friction coating from the piston. You may be able to carefully polish this off the cylinder with a scotchbrite pad.

Agree completely with RudolfHucker, clean it up with Scotchbrite and fit new piston and rings, I'm sure it will be fine.

Don't forget to check and adjust/file new rings to give the correct ring end gap.

All the best, Dave.

 

[Gasser Nate]

There are bristle brush type hones made for nikasil that will most definitely clean up marks like that and are safe to use. My old 04 gassy had over 20,000km on the plating and was still within spec. The key in my opinion is to not try and get 100 hours out of pistons. I do mine at 50-60 hours max and have never had any seizures. See if this link works. http://www.enginehones.com/niapho.html

 

[Zman]

Also run a good quality premix oil at an appropriate ratio. How is the bike jetted? Did you ever run out of fuel while under a high power condition?

 

[gasgasman]

There are bristle brush type hones made for nikasil

+1
I use the ball hone just to knock the glaze off the cylinder.
You can't go hog wild with it. Just a couple easy passes.