Mercury 2.5 V6

**warlo527** · 07-20-2021, 01:24 PM

Hi all, I have a 98 Mercury Sportjet 175. OE353555. I have done searches and wanted to run this by you folks. I have had the motor for 20 years and only replaced a stator about 15 years ago. So she has treated me well. Just had the carbs and fuel pump rebuilt. New fuel lines, reeds, spark plugs, fuel filters. The motor runs fine for 10-15 mins and then it suddenly drops RPMs and has a deeper tone and overall sounds terrible and if I bring it to idle...it will stumble and die. I can limp back to shore at about 2 to 3k rpm but do not want to push the engine.

I can let the engine sit over night or a few hours and it starts up fine and then 10-15 mins later same issue. I installed clear fuel lines to insure fuel flow and no air bubbles to carbs. I then took off the plug boots off one side of the engine and it seemed that the plugs on one side removed..the engine would not even attempt to turn over. So I figured one bank is dead. Then I performed the test a couple more times and all of a sudden the other side was only firing so the problem is intermittent between 1,3,5 and 2,4, 6.

With the research I have done on this forum..seems like stator is leading the way, then swithboxes and trigger last with possible carb issue running far behind. With the symptoms described am I on the right track with stator? My previous stator issue was easer to diagnose as only the high speed circuit was working which is very common. I don't have the DVA meter. Just looking to see if I could eliminate any of the components based on your guys skills and experience.

**LakeFever** · 07-20-2021, 02:27 PM

Stator is my guess. My first V6 did the same thing but by the time I replaced the stator I had already replaced the switch boxes, plugs, wires and ign switch. Considering the age and the sensitivity surrounding old electrics maybe if funds permit its time to freshen all the electric up for another 20 years? Might save you a lot of time and hassle