i have a wiseco 10:1 compression piston and i have 93 octane premium gas with octane booster that boost up to 4 to 7 points. It pings when i give it a lot of gas trying to accelerate and when i put it in 5th gear.
Right when i get it out when it is cold it won't ping till it gets warm about 2 minutes later. know what to do.

 

You can boost your octane with fuel additives or use some high-test racing fuel.

Retarding the spark slightly may help (although some potential performance may be lost).

You could lower the compression ratio slightly perhaps by adding an extra headgasket or shim; however, you'd sacrifice some high-compression power advantage there.

I think pinging after warm-up may indicate thermal expansion of piston, rings, etc., to give a good seal.

Good luck.

Tree Farmer

 

That isnt cool, I once rebuilt a XR200 with a 10:1 pistion..it had a funkey pistion slap knock that sounded kinda like pinging when under heavy throttle..If yours is truley pinging id frist try going one step richer on the main jet and lower the clip on the needle one notch..lean jetting would cause hot pinging. if that doesnt work, try the other stuff on the post before mine, as those are the only other things to do. Joe