77 evinrude 200 missfiring i think

[heftylefty]

Well I got a 77 200 evinrude and I think its misfiring. I have changed coils, power packs, plugs, wires, and a leaky fuel pump. The compression ranges from 90 to 100 on all cylinders. It has a bad skip on the low end but once you get above a certain rpm it runs great. If I had to guess because I don't have a tach it would be about 2000 rpm. Somebody please help me.

 

[Bob_VT]

Re: 77 evinrude 200 missfiring i think

Use a timing light and look at the flicker. and check each plug....... now the carbs will also have a huge effect on low end performance. Were they rebuilt this season? The low speed passages in one may be clogged and it might only work on the high speed ones...... I would suggest a by the book diagnosis

 

[emdsapmgr]

Re: 77 evinrude 200 missfiring i think

Are you experiencing the miss when out on the water, or when it's on the trailer? The carbs on this older engine only have idle and high speed jets. Hard to attribute the mid-range skip to the idle jets and if it runs fine at WOT, it's hard to fault the main jets. It's possible you've got an ignition miss which gets hard to distinguish at higher rpm's. Agree with checking the spark on the plugwires when under power. An inductive timing light will help you here-watch the flashes from the gun head and compare all 6. Keep in mind that weak ignition components tend to fail once the engine heats up to normal operating temps-so make sure it's fully warmed up prior to diagnosing. Might be good to check the stator voltage output. You can find some good ignition troubleshooting info at this website: cdielectronics.com

 

[heftylefty]

Re: 77 evinrude 200 missfiring i think

How do I check the voltage at the stator? When I take the power pack covers off and I touch one of the wires to the voltage meter the engine shuts off. It also seems to shut off when I check the spark on the number 3 cyl. It has spark but the rest of them don't do that

 

[emdsapmgr]

Re: 77 evinrude 200 missfiring i think

Sounds like something is grounding the pack. An unusual failure mode, for sure. The website should indicate how to measure the volt output of the stator. Your engine's guide starts on pg 39 of CDI's troubleshooting document. You'll need a special "peak reading" voltmeter. While you are checking the output of the stator, you might as well check the voltage output of the timer base also.

 

[heftylefty]

Re: 77 evinrude 200 missfiring i think

I was checking the spark with the timing light and I waved the timing light past the power pack and I was getting spark. Does that sound right? I also bought a voltage meter but I guess I bought the wrong one is there a different way to check the stator? My timing was a little advanced so I fixed that. It sounds a lil better but its still not right

 

[emdsapmgr]

Re: 77 evinrude 200 missfiring i think

I check for spark by comparing the flashes from the timing light gun when attached to each of the 6 plugwires. Compare the spark intensity, check for misses, weak flashes or intermittents. Best to check when the engine is under load. (Idling in gear in the lake.)
Likely the CDI website also had ohms checks for ignition components. I seem to have better luck by measuring actual output voltages.