interpret Compression Test results

[Anonymous]

Hi guys

I have a question about my compression test results. I have a 1980 GS750E, just had a carb sync and valve adjustment done at a local bike shop. I have the compression test results but I don't know if they are good, average or poor numbers. Looking for some imput.

Compression 150 - 160 lbs all four cyl.

L.D. (is this the wet test?) #1-4%, #2-5%, #3-7%, #4-4%

Thanks for your help

[RacingJake]

The compression psi for a 82 gs1100 is between 128 to 171 psi.
Min- is 100 psi and max difference between cylinders are 28 psi.

So looking at your numbers I'd say they look good.

[cbxchris]

You really couldn`t ask for any better. Congrats you seem to have a very healthy engine.

[Anonymous]

You really couldn`t ask for any better. Congrats you seem to have a very healthy engine.

Thanks Jake/Chris,

So what are the L.D. numbers?

[gsbill]

LD is your leakdown percent per cylinder. The smaller the percent the better. It measures each cylinders ability to hold compression....You have good numbers there too.

[cbxchris]

That stands for leak down. They bring your engine on top dead center for every cylinder and inject air into the cylinder. With guages you can tell how much leakage there is. By listening you can most times tell where the leakage is. For a street engine that is very acceptable.

[cbxchris]

you beat me to it bill....

[gsbill]

[RacingJake]

Yeap, Fast at the track & on the Resources.