447 crankcase pressure testing
in 2 Stroke Technical Questions
10 years ago
Hi Folks has any one done a crankcase compression/vacuume test on a rotax 447, I have removed the cooling covers and blocked all exhaust and inlet ports with cover plates and pressureised one cylinder the fan end to 7psi, to my supprise the air leaks from one crankcase to the other and unless I block the other spark plug hole and fuel pump pulse port it wont hold the pressure I switched to the other cylinder the same happens, but when I block the pump port and other plug hole it holds the pressure as it should.
My questions are, bearing in mind I have never split a crankcase of a 2s Rotax
. Is ther an internal balance hole between the cylinders that will allow this to happen or is it part of the internal seal design or worse a seal failure problem.
. Has any one got figures on pressure limits for the crankcase
The reason I am doing this is the engine is in for the 100 hour check and decoke
Any advice would be welcome
My questions are, bearing in mind I have never split a crankcase of a 2s Rotax
. Is ther an internal balance hole between the cylinders that will allow this to happen or is it part of the internal seal design or worse a seal failure problem.
. Has any one got figures on pressure limits for the crankcase
The reason I am doing this is the engine is in for the 100 hour check and decoke
Any advice would be welcome
