Yea I thought about the fake plugs too but the es plugs came from advanced and the eix plugs came from my buddies dad and they have been in his tool box for years. I don't know enough about compression and fuel to know what to run. I know it needs race fuel and I run 110. I'd have to take the head off to measure for the fuel ratio
If you pull the head and look at the outer edges of the piston and head, I think that you will find evidence that the engine has been experiencing detonation. Evidence of detonation will show up as a sand blasted look around the outer edges of the piston and head near the cylinder wall. Severe detonation will erode the edge of the piston and head, eat away at the ID of a rubber o-ring or eat away the steel fire ring of a metal head gasket.
On this engine detonation occurred first rattling the plug loose. A loose spark plug cannot dissipate it's heat to the head. A spark plug dissipates it's heat through the spark plug base washer and threads into the head. The spark plug center wire and ground strap severely overheated and became the ignition source known as pre-ignition. Pre-ignition always occurs before the spark occurs. Pre-ignition ALWAYS ignites the mixture to early and has the same effect as overly advanced ignition timing. Pre-ignition causes the engine to experience more severe detonation as a result of the early initiation of the combustion process from pre-ignition which leads to more detonation that leads to more pre-ignition...to more detonation until the engine is experiencing detonation every engine revolution. (run away detonation) Escalating advancement of the ignition timing from pre-ignition continues until the spark plug fails and shuts the engine down or the engine runs until it burns a hole in the center of the piston if the rider continues to ignore the engine begging and pleading for the rider to stop punishing it with detonation.
The most common cause of death on an engine's death certificate is run away detonation.
The most common cause of detonation are listed below in the order we see the most piston failures
1. Fuel octane is too low for the engine package.
2. Improper throttle control from the rider for the RPM and load on a high performance two-stroke engine.
3. Lean A/F ratio due to the tuners unrealistic expectations of how responsive and smooth a high performance two stroke engine should run at the lower and mid RPM range.
4. Too much restriction in the pipe stinger and or muffler
5. Ignition timing too advanced.
6. Too much compression and or lousy cylinder head design.
7. Coolant/engine temperature is too high.
8. Wrong spark plug heat range of electrode/ground strap configuration for the way the bike is being ridden.
Points 2 and 3 are very difficult to explain to a customer because of their lack of understanding of the phenomena that occurs during one engine revolution of a highly developed two-stroke engine. Two strokes are mechanically simple but much more complicited than four strokes when it comes to an in depth understanding of what happens when they are running and why it is happening. I may attempt to explain some of the phenomena when I have many hours to try and scratch the surface on this complex topic. I can explain it to you guys but I cannot understand it for you.
This engine was experiencing run away detonation. On the onset of run away detonation, intermittent detonation can easily be heard. If corrective throttle control is not immediately executed, the intermittent detonation will escalated to run away detonation condition where the tone of the engine changes and a very slight power loss WILL OCCUR until spark plug and or piston failure occurs or the rider implements immediate corrective throttle control.
