200hp Johnson 1977

gwilbur

Recruit
Joined
Aug 25, 2001
Messages
2
Hi guys and gals,<br />I previously posted that I have a 1977 200hp Johnson that only gets about 4000rpm at WOT.<br />JB suggested I should be getting more and recommended looking at the engine performance rather than propellers.<br />I have since done spark tests on all six cylinders with the following results<br />Port side - 2 cylinders had no spark one cylinder had a firm steady spark with a good sounding "crack"<br />Starboard side - 1 cylinder had no spark but the other two also had firm steady sparks with good sounding "crack"s<br />I can't check the plug wires because they are integral to the coils (all the wires going to and from the coils are potted and not removeable)<br />However I installed my spark tester in each plug wire and checked resistance from the power pack on each side to the spark tester on each cylinder (installed the spark tester to be sure I had a good connection to the plug wire underneath the rubber insulation on the plug wire)<br />results <br />Port side - the sparking cylinder showed 1.275k-ohms. The non-sparking cylinders were inconsistant but one seemed to be able to read no better than abt 2M-ohms (note change in order of magnitude) the other seemed to be no better than 200k-ohms (again much higher than the sparking cylinder)<br />Starboard side - all three cylinders read a steady 1.25k-ohms to 1.33k-ohms<br />It appears to me that I have two bad coils on the port side and a possibly bad power-pack or sensor coil on the starboard. Unfortunately I do not have access to the neon tester referred to in my Clymer shop manual for Johnson outboards in order to do their suggested Power-Pack and Sensor-Coil tests.<br />I would like some thoughts from the board before I go spring for new coils and a power pack.<br />Thanks a lot everybody
 

clanton

Rear Admiral
Joined
Jul 9, 2001
Messages
4,876
Re: 200hp Johnson 1977

Peak reading meter or adapter www.esitest.com. After you get meter start with stator charge coil output test. Look in manual for newer engine 1979-84 CD3 and CD6 troubleshooting, use these voltage output spec, and do the power pack isolation diode test.
 
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