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Spark or no spark...that tis this question.
So the problem im having with my 90 Evenrude VRO 120 hp is that sometimes.it.cranks on first turn and then it just cranks and cranks. I tested spark plugs for fire, they do not have fire when it acts up, but does when it finally runs. A friend mentioned the power head which is a good guess but wouldn't those go out and be done, instead of causing me to be able to start it once again. It never quits when it's running. Only after I've turned the engine off. Please help with next step.
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Your friend probably mentioned the "Power-Pack".... the powerhead is the block with all the components (crankshaft, pistons, etc) installed.Originally posted by dbeasley36042 View PostSo the problem im having with my 90 Evenrude VRO 120 hp is that sometimes.it.cranks on first turn and then it just cranks and cranks. I tested spark plugs for fire, they do not have fire when it acts up, but does when it finally runs. A friend mentioned the power head which is a good guess but wouldn't those go out and be done, instead of causing me to be able to start it once again. It never quits when it's running. Only after I've turned the engine off. Please help with next step.
First check the stator under the flywheel to see if there might be a sticky looking substance dripping down on the powerhead, if so, replace that stator as the dripping would indicate that the stator is suffering a voltage drop to the powerpack when the stator gets hot.
Note that the spark test should be done with all of the spark plugs removed and the test gap should be a 7/16" gap.
(Spark Tester - Home Made)
(J. Reeves)
You can use a medium size philips screwdriver (#2 I believe) inserted into the spark plug boot spring connector, then hold the screwdriver shank approximately 7/16" away from the block to check the spark or build the following:
A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.
Using the above, one could easily build a spark tester whereas they could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:
..........X1..........X2
.................X..(grd)
..........X3..........X4 -
Yes he meant power pack. I bought a spark plug tester so I wouldnt shock myself. Its running now so gta wait till it doesnt to check right?Comment
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Yep... it's got to be acting up to do a proper test.Originally posted by dbeasley36042 View PostYes he meant power pack. I bought a spark plug tester so I wouldnt shock myself. Its running now so gta wait till it doesnt to check right?
Another thing.... When it gets to a point where you absolutely have no spark AND the stator looks and checks out okay.... remove the black/yellow wire (Kill circuit) from the ignition switch. If that brings back the spark, replace the ignition switch as it has a intermittent short.Comment
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Alright no spark and no goo coming from stator. It seems when the engine gets hot is when it stops firing.Comment
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That normally indicates either a failing stator or a intermittent ignition switch short... and since there's nothing dripping from the stator, if it were me, I'd be removing that black/yellow wire from the ignition switch (temporarily) to see if that cures the problem.Originally posted by dbeasley36042 View PostAlright no spark and no goo coming from stator. It seems when the engine gets hot is when it stops firing.Comment
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Alright, Joe let me deeply thank.You for all the help so far, this has been really helpful. So, that said.....once I disconnected the yellow/black wire from the ignition my engine should start correct? And, if it doesn't?Comment
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With the black/yellow wire disconnected... if the ignition switch has a intermittent short, the spark that is required should now exist. Your complaint is that at times, there is no spark (ignition) and we are looking for the cause of that problem.Originally posted by dbeasley36042 View PostAlright, Joe let me deeply thank.You for all the help so far, this has been really helpful. So, that said.....once I disconnected the yellow/black wire from the ignition my engine should start correct? And, if it doesn't?
Whether the engine actually starts and runs depends on everything else being as it should be.Comment
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Gotcha, I will check first thing in morning. Be back with the news, thanks again JoeComment
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Ok, I'm happy to report, I think, that it is getting fire on 3cyl. But not the 4th. I removed the coil and cleaned the ground but still no fire. Could 1 bad coil cause this?Comment
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Note that a spark test is always done with "all" of the spark plugs removed in order to obtain the highest cranking rpm.Originally posted by dbeasley36042 View PostOk, I'm happy to report, I think, that it is getting fire on 3cyl. But not the 4th. I removed the coil and cleaned the ground but still no fire. Could 1 bad coil cause this?
To test a coil.... you could simply change the wiring from one of the firing coils to the non firing coil temporarily... OR... physically switch the non firing coil with a firing one... whichever is easier for you.Comment
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So I didnt get on here quick enough to let you know it stopped firing again. So apparently I could have a coil issue as well. When it was running I heard the misfire. I did take off the kill switch wire...no fire. I also changed the ignition switch with a new one...no fire. When the engine runs for awhile something had to be getting hot and just stops working. I garauntee it will fire in the morning.Comment
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You could disconnect that black/yellow wire directly at the powerpack that leads to the ignition switch to test for a intermittent short within the wiring harness.
The fact that you have spark when the engine is cold but not when it's hot leads me right back to the stator. I'd suggest that you remove the flywheel in order to inspect that stator closely for a melt down scenario.Comment
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UPDATE..... I replaced the stator with a new one it was very sticky and melted but was reading the same ohm as new one. After replacing im back to.same problem.
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To test any coil.... Find a coil that is firing properly.... there will be a orange wire leading from the powerpack to that firing coil.... temporarily switch that wire to the non firing coil.
If the non firing coil now fires, then obviously the coil is okay. If not, then the coil is faulty.
Let us know what you find.Comment
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