Logo

Cylinder leakdown test on 2 strokes

normo

New member
"I'm a backyard mechanic l

"I'm a backyard mechanic looking for a used 2 or 4 stroke motor. Ran across an article stating that a cylinder leakdown test is much better than a compression test for revealing problems. All the examples were for 4 strokes. On this forum's archives I read where this test is meaningless for 2 strokes.

1. Can someone describe whether a cylinder leakdown test is valuable for a 2 stroke?
2. If yes, should the piston be at tdc or slightly before?
3. How do you interpret the results? I want avoid an engine that will definitely need major work in the near future. An article on 4 strokes said that a good reading is 5%, acceptable is 10% and 20% or more means repairs in the near future. I read on this forum's archives that on a 2 stroke, 35% means the engine is ready for rings. Don't understand why there would be a difference between 2 and 4 stroke motors.
3. Since I have gauges and a hose I would like to make my own leakdown tester. What is the correct restricter orifice diameter for a 2 gauge setup?

thanks"
 
"Another question I forgot:

"Another question I forgot:

When pressurizing the cylinder to 100psi, what is a safe way to secure the crank so it doesn't turn?"
 
You dont need to do a leak dow

You dont need to do a leak down test on a two stroke just a compression test and if the comps are within 10% great no problem leak down tests are for four strokes dont believe anything different
 
Back
Top