just bought a 76 magnum with this 86 merc on it. previous owner(s) did hatchet job & tossed engine harness. i have regasketed carbs,piecemealed wiring to get spark but now i have to get new battery old one wont cut it. my question is -- the tube coming out of cyl head is routed forward but deadends midway in housing & seems to have been cut, now where does this 1/8" tube connect to?? thanks danmar