3.0 merc died and now there is no spark

vroom ZOOM

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Aug 15, 2017
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427
Hello

This merc gave me a few problems, including a stupid steering pin that got so siezed up that it wouldnt let me steer, forcing me to pull everything apart, then I screwed up the engine mounting, then the fuel gauge broke etc. now I got a new one that has me stumped. A few days ago I was water skiing, dropped a ski (my dad was driving) then after a while I decided to do something stupid and of course I fell off. well, I got picked up, boat started and ran fine, until after a couple of minutes it just died (it was running at about 1500 rpm when it died). well I thought it I ran outta gas b/c the fuel gauge doesnt work yet. well I had a jerry can with me so I filled er up but no dice. motor turns over as usual, but no firing. I pulled the flame arrestor off thinking maybe the pump didnt prime but I disconnected the throttle linkage and pushed the throttle crank with my finger and there is gas squirting out of the accelerator pump. well then I thought it must be spark. when cranking over there is no sign of firing and if I crank a while I start to smell gas. Of course I run the blower cuz I dont want my still cheap boat, even after so much parts, to blow
smile.png
. I pulled the wire off of the coil, and yes there is spark from the coil when cranking, but nothing from any distributor terminal. Well I though yep I shouldda done the cap and rotor, part of regular maintenance.well the marina did not have a cap and rotor, so our friend towed us back to the ramp. just bought a cap and rotor today, put them in AAANNNDDD.... nothing. same thing, nothing from the distributor, but the coil still zaps. What the heck is going on?
 

alldodge

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Its a 3.0 and what year, or better yet what is the motor serial number?
 

alldodge

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Need a spark gap tester. Is the spark jumping at least 1/4 inch and is it blue or white?
 

vroom ZOOM

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Aug 15, 2017
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427
Yeah, it is jumping more than a 1/4 inch. spark is orangey when jumping that distance. bear in mind that the battery was getting a little low. I will get a better tester and test again.
 

salty3rd

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Jul 13, 2010
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109
Is the distributor turning when you crank the engine?
 

alldodge

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spark is orangey when jumping that distance

Not good, orange is not enough to pass thru the wires and have enough left over to spark the plug gap

TBV Troubleshooting.jpg
 

vroom ZOOM

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Aug 15, 2017
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427
Well guys I am kinda confused as to what part I have to replace. the spark from the coil is weak, but is it necessarily the coil causing the issue? I dont want to just go ahead and buy the expensive coil without being certain that it is causing the problem
 

alldodge

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Test the distributor to see if it checks out. Then test the coil to see if anything shows up with incorrect values

EST Dist Coil 1.jpg
 

vroom ZOOM

Chief Petty Officer
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Aug 15, 2017
Messages
427
Ok, i have done the testing, and here are the results:

pickup coil test:

- GRN to GRD: infinite
- WHT to GRD: infinite
- WHT to GRN: 437 ohms

coil test:
- b to GRD: infinite
- b to c: 0.1 ohms
- b to f: 0.1 ohms
- b to a: 1500 ohms

hmm that coil seems busted
 
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