My engine is a 1985 Mercury BlackMax XR2 150.
I had an unexpected failure last week at the lake. I replaced the impeller about a year ago, and it's been running fine. Dropped it in the water for a run, took a couple laps and stopped. Then I started it up, ran it wide open, and then it started sounding like only 1/3 the cylinders were firing. Its died & I couldn't get it to run, except with it in neutral, wide open - and then it even sounded like 1/2 the cylinders were running. I pulled it out & went home. At home, I could see pieces of the impeller in the water intake of the lower unit. Obviously - a failure.
I've replaced the impeller, and the water pump housiong and seals to be safe.
Now, I cannot ID the problem with the power head. I guess it could have overheated some, but not much (my temp guage & buzzer are gone). I've run much hotter than that in the past. My guess is that one of my switchboxes has gone kaput - hence giving me 1/2 the engine firing. I did do a test on the plugs, and I do get a spark, but very weak on all 6. Maybe the heat fried the switchbox on the block (sparing the 2nd one that piggybacks it)? I see no block or piston damage, and compression is pretty much equal on all 6.
Any ideas or thoughts?
I had an unexpected failure last week at the lake. I replaced the impeller about a year ago, and it's been running fine. Dropped it in the water for a run, took a couple laps and stopped. Then I started it up, ran it wide open, and then it started sounding like only 1/3 the cylinders were firing. Its died & I couldn't get it to run, except with it in neutral, wide open - and then it even sounded like 1/2 the cylinders were running. I pulled it out & went home. At home, I could see pieces of the impeller in the water intake of the lower unit. Obviously - a failure.
I've replaced the impeller, and the water pump housiong and seals to be safe.
Now, I cannot ID the problem with the power head. I guess it could have overheated some, but not much (my temp guage & buzzer are gone). I've run much hotter than that in the past. My guess is that one of my switchboxes has gone kaput - hence giving me 1/2 the engine firing. I did do a test on the plugs, and I do get a spark, but very weak on all 6. Maybe the heat fried the switchbox on the block (sparing the 2nd one that piggybacks it)? I see no block or piston damage, and compression is pretty much equal on all 6.
Any ideas or thoughts?