94 Johnson 150 faststrike cutting out

[Speakrdude]

I'm sure this has been discussed many times but I couldn't seem to find the answer. My engine was running great then after about 30 min's my WOT rpm's dropped from 5100 to 4500. If you runa t 35~4000 rpms, you can feel it cutting in and out. Sounds like 1 cylinder misfiring. I replaced all the plugs (QL78's) no change, changed fuel/water sep., no change, ran B-12 through fuel tank, no change. Replaced power pak and sensor about a year and a half ago with new OMC pak so hopefully not that again. It seems to cut out more after it warms up now and the "fast start" system seems to be going on and off alot. Real erratic idle 800~1200 rpm's up and down. I did some troubleshooting while on the water with a timing light yesterday and it seems like maybe #3 is intermittenly firing. Hard to tell at fast idle though. Any dother test a Do-it-Yourselfer can do other than just the "try and buy" method? I have a buddy with a shop that has the DVA tester so that might be the next step. <br />Jim

 

[james roach]

Re: 94 Johnson 150 faststrike cutting out

Swap a coil out and see if the problem moves to another cylinder.

 

[Speakrdude]

Re: 94 Johnson 150 faststrike cutting out

Used the timing light today to check coils while under a load (on the water) Problem #3 cylinder coil. Moved coil from #3-4 to #1 -2 position. (dual coils) Ran great for 10~15 minutes., Then same cut-out. Checked again with timing light, #3 cylinder still the problem. Down to either the power pak or the sensor. Tomorrow, I am trying a diff sensor. <br /><br />Jim

 

[kevin Ron]

Re: 94 Johnson 150 faststrike cutting out

Look at 95 175 Ocean Pro's answers could be your problem to.

 

[holy ghost flies]

Re: 94 Johnson 150 faststrike cutting out

i had a simular problem i changed the thermostats and my gas lines had a hole in in and was cracked. my alarms was going off left and right until i fixed the fuel issue.