Re: OMC outboard dies after about 1.5 hrs
Gerald--I just read a couple of articles in the October issue of Go Boating which addressed stern drive shift problems. I don't know if what they said applies to you, but it might be a start. There is a shift interrupter switch on outdrives that momentarily shuts down half the engine to allow shifting of gears. The article says "This switch is normally the connecting point between the shift cable coming from the console's control box and the shift cable going into the outdrive. If the cable going into the outdrive is balky--and it will get like that every three years or so--the interrrupter switch will be balky itself, and the engine will stall between shifts...There's no shortcut cure for this. No adjustment will make it go away, and the cable can't be lubed properly without stern drive removal. So, if you have to remove the outdrive to even lube the cable, why not replace the cable in it's entirety?" A second article says "This (the shift interrupter) system is more prevalent on stern drives than on outboards; however, the design of a stern drive requires two cables: one coming from the forward control to the engine, where it meets a second one that goes into the outdrive. Outdrives are almost always submerged, so the second cable becomes sticky with corrosion and hampers movement of the interrupter switch leaving the engine to run on half power longer than it should. This invariable causes the engine to shut down at the worst possible times--like when docking or approaching a trailer. At that point, stern drive owners need to bite the bulle, forget about minute adjustments and replace the cable." I'm not a mechanic, so I couldn't make a guess as to whether your problem is the shift cable, overheating forward gears, or engine issue, but sometimes heat generated by extended use does funny things to systems that run normally under most conditions. I have a 1996 Larson I/O, by the way, and it's a real fine boat. I hope this may be of some help.
