low compression, should i worry?
 

alright i picked up an 87 fc for cheap because the guy i am getting from says it has low compression, but it starts, idles and runs great with no loss off power. im not sure if he checked it with the motor cold or warm but i do know he told me it needs a new battery, so as long as its running good should i not be worried or just re-test when i get it back home? i was hoping to just add in some oil conditioner and see what happens, thoughts? and if i did want to rebuild is thier a place that i can just order a rebuilt ported motor "crate 13b" and if so can i get the site for it. thanks alot.

re-check the compression. make sure the motor is turning over at decent rpms and youhave the throttle wide open.

Don't do that.


-Ted

There is a compression test "how-to" on our website www.banzairacing.net . If it starts runs, drives with no signs of low compression then what are the readings that the previous owner got? Checking the motor cold or warm will only yield compression changes of a few psi. This sounds like he took it to the Mazda dealer and they didn't want to be bothered with it so they told him it needed a new motor.

as far as i know it tested 75psi on the front rotor and 55psi on the rear, he checked it himself with a comp. checker for a piston motor. but those numbers seem really low for it to be running perfectly, why is it a bad idea to add in an oil conditioner? wouldnt it only help the seals?

With those #'s it would not start well, idle well or drive with a lot of power.