All 2st WR250 Engine seizure

The piston is visible in the pic here on the first page above in my opening post.
Yes, indeed a hole.
There was a quite big hole at the HTS gasket and has maybe some kind of relationship with the problem of the piston.
The HTS gasket would be in the area were the piston is damaged too.
As far as cooling concerned, i know that the cooling jet impellor could use replacement, I need to do that too. some point.
The cylinder wall is fine now, just waiting for the new piston, gaskets, impellor and throttle cable to be delivered.
Everything to be checked on air leaks during installation next weekend.

I checked the throttle cable last sunday, and removed the cable itself from the hose, no problems, unfortunately it looked really fine, it would be so easy to replace only that.
So now I need to investigate the carb.


Carb:
Needle 6DJ8-60
High speed jet 410
Clip 3,5
Clip position 2nd from above (used to be 3rd from above)
Pilot 30
Mixture air screw about 4 rounds to the left.
Altitude is sea level

Another question.
For installment of the piston, do I need to heat the crank hole in order to fit the piston pen?

we used to run the jetting as follows 32.5 pj 60 needle 3rd clip with a 410 main 1.5 turns out on the air screw. hope this helps

That's identical to the settings that I had.
Are you at sea level?