Bad Powerpack? 1996 Johnson Fast Strike 175hp

Just bought this boat last week and ran it fairly successfully the first few hours. Was running great at an idle and 3/4 throttle but would occasionally misfire at full throttle. A few times it died at full throttle almost like someone hit the kill switch. When it did die it would start up again within a minute and run perfectly normal. A few days later I took it out again and it started perfectly and ran fine at idle and low speed. Couldn't even get it opened up without misfiring this time. Misfired maybe 3 times and then shut down completely after about 3 minutes of running. Finally started again after 10 minutes of cranking and got it opened up to half throttle and died again. Now can't get it started again.

I'm getting fuel no problem but not getting any spark now. Engine cranks strong. I'm thinking the powerpack which I don't mind replacing since even if it isn't bad it would be a good idea to have a spare with the age of the motor (350 hours).

Before you replace the pack go to cdielecteroics.com and look up their trouble shooting procedures.

Just how my ignition system acted as it died slowly. Heat shuts it down faster & faster.. Never gets better.

Thanks guys. I replaced the power pack and it fired right up. I went ahead and replaced the optical sensor as well. I'm hoping to get it out on the water in the am. I'll let you know if it runs just as we'll under load.

last summer I was coming home wide open and my 1981 Johnson 90 hp just felt I lost atleast 1 cylinder . since then I have changed power packs coils and now stator. while it runs once in it will come back to full power. almost about to give up I guess the last thing might be timer base.I don't believe its a fuel issue I sprayed fuel while it was struggling and no change. anyone have any ideas let me know.

Post compression test values first.

I will do another test but that was one of the first things I did and they were all good I will do a retest.

What happened to the original poster ??