Just bought a 1990 miata, one of the cylinders have low compression. Any one have any ideas why?

 

How many miles?

 

220000

 

More than likely it's a very tired old motor that needs new rings.

What cylinder is it low on? My guess is #4

 

how about you google "low engine compression" and find out all the possible causes? Then you can focus on ruling out the individual potential causes?

Oh wait, i forgot we have these crystal ***** we can use and figure out whats wrong for you. Next time give us even less information, if thats possible, to figure out whats going on.

 

I'm going to go out on a limb and say that you probably have low compression because either your cylinder has some sort of leak, or the piston isn't reaching as high as it should. That's about all I can tell you from the info you provided.

 

it's because you're dumb and lazy