Lean Seizure

[Eugene]

Why is everybody talking about lean seizure. Why does a lean condition lead to a seuzure?

[96xp800]

Re: Lean Seizure

Too lean means there is more oxygen than fuel. This causes combustion temps to go through the roof. The excess heat causes the piston to expand larger than the bore diameter and it hits the cylinder walls causing it to seize. Two stroke motors are very sensitive to this problem so it's a big concern when rebuilding motors and carbs or modifying the intake system.

[Eugene]

Re: Lean Seizure

OK, got it.
Anyway, if I use a 93 gas instead of recomended 87, and add 50% more oil in a gas, would it help? I have a problem reading spark plug test results using Synthetic "Intercepter" oil. The rim on a plugs looks like a "new" for the last 20 -30 hours, since I switched to Amsoil "Intercepter". (See http://server1.sbtontheweb.com/forum...ad.php?t=15571 )
Thank you.

[Bill O'Neal1]

Re: Lean Seizure

Raising the octane without raising the compression never helps. If you model is susposed to have 87 in it, then run 87 octane fuel. Adding extra oil leans a fuel mixture as the oil must go through the same jet as the fuel in a premixed ski. 40 to 1 is a very conservative mix, more than that is wasting oil unless the motor is a high compression, high reving motor, then 32-1 may be better.

[Eugene]

Re: Lean Seizure

Got it. Thank you.