i have a montgomery ward seaking 7.5 clinton motor i believe the year is between 78-80 my mod# says XTV50507B but i believe it should KTV, ser#1576203, type K751-6107-A, i bought it froma guy who could not get it running, he replaced all the ignition parts, i got it running but it makes a clanging noise at low idle like something is catching, sometimes it does catch and stops running, it seems to run fine at fast idle though! i would appreciate any suggestions or advice from anyone, or if anyone has any diagrams or manuals.