Location: Marlboro MA
Joined: Dec 8, 2007
Points: 1328
Compression test questions Original Message Jan 29, 2008 6:55 pm
After checking around the net and the library I have some questions about compression testing.
Is it correct that 60 is the general line for good and bad compression in snowblower engines?
Is 90 to 150 the expected for a new engine?
When you take a reading I think the cylinder would empty each cycle but not the gauge. If you go through several cycles of the engine then the needle seems to jump up at the first few rotations, then bump up a little more on the remainder, and finally hits a high point.
It seems that only one cycle would give a true reading but that does not seem to be the case when using the rope pull. The gauge moves more with a full pull and even more with a few pulls. When I use the electric start the readings are higher still.
What's the correct method of doing a reading for a small engine? With multiple turns of the engine the readings seem to be additive up to a max reading. ?? Dawei
