Home › Forum › Ask A Member › Beginning a CD-12 adventure › Re: Beginning a CD-12 adventure
in the last picture i see some pretty significant rust and scoring in the top cylinder wall that would cause the low compression readings.it looks to me that the motor was stuck from rust at one time or another, someone unstuck it, and tried to get it running.the scoring was there before it got rusty, probably from an overheat from a bad impeller,or possibly inadequate lubrication,if you magnify the picture, the rust pitting becomes apparent. with all of the issues this powerhead has, and i know this isnt what you want to hear, but i would replace the powerhead with a good one. the cylinder needs not only to be smooth, but it also needs to be round and straight. i would also imagine that the rings in that cylinder are probably stuck,and likely need to be replaced. the new round straight rings are not likely to seal in that cylinder….for the best possible result with the project,i would find a good complete powerhead,or a donor motor of the same year that has one.it would take care of the other issues also….art b