I have an old 9.8 mercury O/B (referred to as a thunderbolt 110) probably year 1975-1978 that starts on 2nd pull and runs absolutely fine cold for say 15-30 minutes.
After it has run for a while, it looses power. Plugs are fine. It was suggested to me that it could be the head gasket sucking air (would this be same hot or cold?) or the pickup coil not working properly when hot.
May not be an easy fix but in the meantime we have just run for short periods. It still runs when hot but just with lack of power (at about 5-10 mph).
Has anyone experienced this and know the solution to repair?
In addition, is there a "cheap" location in Canada for merc O/B parts?
and, how can I tell the exact year of this motor?
Thanks Baffled
