I would suggest Looking Into a possible leak at the base gasket...

New problem sounds more like excessive blow by or crankcase pressure... (the oil you’re seeing is more than likely coming from the breather tube that routes directly to the inlet side of the air box)... It could be as simple as over filling the engine ... more »

I have one but I can almost guarantee you there’s a bunch of them on eBay for

Measure the bore to make sure it’s still in spec... Then choose a piston based upon your results and recommended piston to wall clearance... By theory it should be a C but that’s not always the case...

He’s more than likely referring to this tool which just allows you to clean/flush the injector... the only other way I could see a shop cleaning a throttle body is to disassemble it and put it in an ultrasonic

You need a degree wheel and a dial indicator... there’s plenty of articles available on how to degree a camshaft properly... its a great piece of information to learn for anyone building engine... It not only verifies that the cam profile is correct ... more »

what was the reason for rebuild/ teardown? It almost looks as if one of the cam gears have spun slightly notice the cam gear teeth are slightly out of alignment... also does the intake cam not have an alignment dot with the head surface? If all else

Warped/cracked head or cylinder... Damaged O-ring or warped cases where coolant passes between them. Was problem existent prior to rebuild?

As mentioned above... it would look like minor pit marks around the edge of the piston and/or combustion chamber of the head... Yz’s do tend to rattle at idle... If you’re that worried about it remove the head it’s only way to know without a doubt... ... more »

If you’re worried about it... drain the coolant and knock the head back off... 30 mins of work and you’ll have your answer to whether or not it’s detonating...

Is the fork tube itself straight/true?

X2

Definitely valve cover gasket... easiest thing to remember when chasing a leak “sh*t runs downhill” not up... please don’t use bars leak either if you ever have a small leak or blown head gasket... fix it the correct way...

Looks like Casting flash I wouldn’t worry about it

Heat the basket back up in an oven or equivalent... gear should fall out with a light tap... then freeze the gear and heat the basket It will drop right in...

When I ran into the problem... sometimes the bike would start, sometimes it would just pop and never start... I found it when I got the bike to fire again... I just sat there moving the wiring harness/connectors around until it stalled...

Ran into a Very similar problem on this exact model during a rebuild... one of the pins in the connector from the stator assembly to the main harness backed out of the connector... symptoms were very similar to what you are describing... worth a look ... more »

Lean condition caused by an Air leak or plugged pilot jet more than likely. What size and make is the carb on it now?

Basically, OP if you don’t have the correct tooling to measure runout... don’t use a screwdriver as “.005” is an absurd amount of runout in a single crank (any pressed crank honestly)... just take it to a machine shop they’ll be able to check it in a ... more »