Fix for Johnson 2000 90HP missing above 3000RPM

[shadetree101]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

Thanks all<br /><br />I have not had a chance to fiddle with the motor recently.<br /><br />I connect the scope leads to engine ground (scope ground) and scope probe to ignition coil primary side. This procedure in manual calls for a peak voltmeter for doing the "Running Output Test"

 

[clanton]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

The voltage at that point should be 200 volts or higher with peak reading meter, I would think a good scope would read the peaks. My first suspect would be pack/sensor, but still needs to be verify with some kind of meter you trust.

 

[shadetree101]

Re: Fix for Johnson 2000 90HP missing above 3000RPM

Not sure if I need to start a new subject or just use this one. The motor is the same but the symptoms are a little different.<br /><br />Yesterday I had the boat out on the lake and had the same problems as stated above however after running the motor at around 3000 RPM's for about 20 to 30 minutes I decided to try full throttle again. The engine ran fine with NO missing all the way back to the marina. It even had no idle miss either and the motor ran real smooth. I then let the motor get cold for a few hours. Got back in the boat and tried full throttle with the same missing/lurching above 3200 RPM's. Ran it again for 20 minutes below 3000 RPM's then had power with no miss at full throttle. The WOT RPM's were around 5200. Any ideas anyone?