New build having issues with detonation!

[2Stroketwin666]

Recently built the Athena 421cc 4mill stroker here’s the list cool head 22cc domes, 68mm Athena big bore cylinders with clean up port, wiseco pistons, hot rods 4mm crankshaft, vforce 4 reeds, 34mm pwk carbs with billet intake, toomey T5 exhaust, dyna tek programmable cdi and coil, k&n pods, lockout clutch from F.A.S.T. Larger radiator.

spark plugs started working themselves out, checked compression after build had  150psi after 5 hrs on new engine have 80psi. Pistons and domes are ruined cylinders are still good. Here are pics. What did I do wrong? Don’t want to get new parts and have this happen again. Oh and running ethanol free premium, should I have been running race gas? 

[Jereme6655]

You’re going to need to do some work….. 

what is your squish, what is considered “premium” where you are at? What is your jetting and elevation?

 Also….. the piston on the right….. is that a hole melted through the top of the piston? 

[2Stroketwin666]

Yes hole starting so figure lean condition on that side

[2Stroketwin666]

93 octane on premium here

[2Stroketwin666]

165 on main 50 on pilot  I’m at 500ft above sea level

[SKEETER]

Trinity spark plug lock is da ticket

[T13]

Are you confident that the dynatek cdi is good? Or the map your on is a good map?

[ClaudeMachining]

Squish and uccr???

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[Jereme6655]

Did you do a leak down test on the motor before running it? 

[kawa110]

Leak down before ran? Leak down before tear down after failure?

What was timing set at?

Both plug straps burnt? One pistons had hole?

[caleb90]

Slap er together and run er fast. No break in no plug chops. 

[ClaudeMachining]

Slap er together and run er fast. No break in no plug chops. 

Yup, it will always amazed me to see peeps pile up parts together without any measurement and hope it will work ok.

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