Scoring at ring gap

[crkid125]

Had a seizure with brand new oem cylinder, piston, ring, pin, etc due to lean condition. Seizure points were up and down the piston at the ring gap and one at each corner of the exhaust port. Had the aluminum cleaned out of the cylinder bore with acid and honed, could feel no rough or raised areas on the cylinder with my finger. Bore was still in clearance and put together with oem piston, ring, etc and richened the jetting to a 40 pilot Blue needle #2 and 410. No air leak. 32:1 maxima castor oil on break in. ran .7 hrs and there is scoring up and down the side of the piston below the ring gap, not terribly bad but grooves can be felt with nail. I can stick my finger inside the intake and feel the bottom of the cylinder wall and it feels smooth. What would cause this?

[heart_of_darkness]

Did you check the ring gap measurement during assembly?

Edited April 29, 2014 by heart_of_darkness

[crkid125]

It had .018

[crkid125]

Bump

[heart_of_darkness]

I always gently round the sharp edges of the ring ends, but that's probably just superstition.

 

If it's a single ring piston, are you feeling a slight bump where there's no wear at the ring gap?

[crkid125]

Not when i put it back together. The bike is together right now but i can clearly see where the ring is

As in i can clearly see on the bore where the gap is

[crkid125]

Bike is also now leaking 1 psi in 10 minutes. Have sprayed and can't find any leaks around intake, exhaust, powervalve, head or cylinder.

[wykyd450r]

Bike is also now leaking 1 psi in 10 minutes. Have sprayed and can't find any leaks around intake, exhaust, powervalve, head or cylinder.

Check the tester itself?

[crkid125]

Tester isnt leaking. I have sprayed it

[frdbtr]

check your crankshaft seals.

[crkid125]