jabowil-RCU

My Feedback: (9)

I have a 140 L that I bought used and had serviced about 2 years ago by YS and it has been sitting in a closet since.

Just got it out to put in a plane and found it has very little compression. Does that seem normal?

I will try to start it this weekend on the bench which will be my first time to run it.

thanks in advance

Jimmy Skids

My Feedback: (2)

A lot of times they will seem low on compression until you run them. Give it a run first and after running try to move it over by hand and you should see/feel some compression.
Jimmy Skids

petec

My Feedback: (58)

Ditto on what Jimmy said. Also after a long lay up period like that I also pull the valve cover to make sure the valves aren't sticking.

jabowil-RCU

My Feedback: (9)

yep the rocker arms don't move when the prop is turned.

any suggestions to repair it?

thanks,

petec

My Feedback: (58)

I use raw fuel and my thumb. Pull the rocker arms, soak the valves down with fuel, and gently push down on the valves to get them to start moving. If that doesn't work then pull the head and soak it for a while in fuel and then work them back and forth.

jabowil-RCU

My Feedback: (9)

Both valves will push down by my thumb, but the pushrods don't cause the rocker arms to move when the prop is rotated.

petec

My Feedback: (58)

Sounds like the lifters are gummed up. Pour some raw fuel down the pushrod tubes and let it set for a while. Then hold pressure on the pushrod side of the rocker while spinning the crank. They should free up. The other thing would be to send it in for a going over.

jabowil-RCU

My Feedback: (9)

OK and Thanks for the suggesstion. I will give it a try.