parrot_eyes
Recruit
- Joined
- Aug 1, 2007
- Messages
- 1
Hi all, new to forums. I have a 1991 merc 350 magnum, I/O, and it over heats pass 3500rpm's, faster nearer to 3900 rpm's. Changed the thermostat, no change. Also, while cruising after 20 minutes or so, my engine "pops" or backfires, especially if i mess with the trim tabs or the engine trim. It will pop with or without me messing with the trim tabs or engine trim but they seem to start the problems sometimes. Very starnge, i cannot pin-point it or predict when it will start or how to make it happen. I am not experienced but looking for idea's to my issues.
