I would say that was a little tight.. the bottom of the skirt is usually the widest point of the Piston.. I would say it was set up without the proper clearance..

 

That or it got mighty hot. Not stock pistons either is it?

Maybe just my phone but I see little crosshatch.
Pistons are usually cam turned below ring area so the biggest diameter is measured 90 degree to the pin axis on its center line.

Harley's pistons with the Teflon coating run extremely close tolerance for a air cooled motor.

What the tolerance for non coated pistons?

 

OK, let's break this down. The reason the OP pulled the top end was because "it started pinging"; crank run out and cam chest components are, IMHO, secondary to the pinging. Did the motor over heat? Did the OP get some really bad fuel? With 20K trouble free miles on the motor, one would think the state of tune would not be contributing factor but we don't know what the state of tune was. If I were the OP, I would be looking for the source of the pinging.

Pump looks good but more pictures of the gerotors, pump housing and cam plate/pump mating surface and cam plate bushing are needed to evaluate condition. Piston scuffing is ugly as is the cylinder scoring but a drop on 110" kit will solve that problem. Pulling the pan for a thorough cleaning is a good idea. Of course new inner and outer cam bearings will be required.

I would still get the oil analyzed just to have the data. JMHO but the crank should be pulled and sent out for repair; .007" can grow.

Still interested in the source of the pinging. If not found, it will still be there after a rebuild.

 

There is a good reason ALL OEM manufactures use coated piston skirts.There should not be a street engine that is built that does not have it, as it been around and used for the past 30 years! As the oil's have changed and the fuel has changed that allow the engines to run cleaner there is less lubrication and higher temperatures in the cylinder wall to piston area. The only reason not to have a coated skirt piston is someone is trying to be cheap and save a buck or two! That said you need to tear the whole engine down and clean everything. Have the crankshaft reworked, trued and balanced. Make sure you inspect the piston oilers as they may have crap in them and its hard to get them cleaned properly.

 

Pistons and cylinders were from Fuel Moto. They are stock cylinders bored out. Fuel didn’t make a difference, even tried some octane booster. Pulled 4 degrees of timing and still had some pinging. Also tried adding fuel through the Quick Tune on the Power Vision, but still had pinging. I’ll have to get pictures of it, but the gear rotors look clean. No obvious sign of damage but I do need to inspect it further. The pump has a magnet that’s caught some metal, as you can see in the pic. It also has a screen in the pickup.

 

Bad tune and overheated. Notice the grooves go all the way to the top. Cylinders were washed and too much timing. If it were too tight the motor would have seized early on. It has 20K on it.

 

don't know what the hell I was thinking... 20k it's a fair amount of miles..

 

General consensus seems to be a tuning issue? It ran great for 2 years and 20k miles. Admittedly I ride pretty aggressively

 

With 30000 volts at the plugs and a nice 60psi spray from the injectors, the motor will burn about anything. Throttle response will be real nice. too much fuel can calm the ping, as can the knock retard. Might have lasted longer if you changed oil every 1000 miles.