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1989 mercury 50 3 cylinder sparks but wont fire... please help

S

slatter

New member
Hi guys

im wondering if anyone can help me with a very annoying problem. Im pretty new to outboard engines but have been around car engines for years.

basically i cant get the engine to fire, sometimes by having the plugs out and putting fuel in the ports it will fire, but majority of time it doesnt. The plugs are sparking when outside of the engine.
could the stator be broken but still be able to make the plugs spark? Ive got the resistance readings and going to test them tonight and going to try and get an adapter for dva for my multimeter.

Its annoying me alot as i cant get my head around it... theres fuel compression and a spark... but no bang!!

any help would be really appreciated thanks james
 
Thanks ill get a spark tester. Battery is freshly charged battrey so definitly spinning over well. Does the spark tester sit in the ht lead in place of the plug for testing?
 
Right bit of an update.... the spark isnt jumping a 7/16 gap. Ive tried starting on easy start and it still wont fire. Ive read resistances but dont have a dva but risitances are as follows... this was with metre set at 20k
blue stator wire to ground. 1.52... which i think means 1520 ohms... should be 5800 - 7000
Red stator wire to ground.. 0.14 .. 140 ohms.... should be 135- 165.
Then from trigger to pack.... all the brown white and purple to ground... should be 800 -1400 ohms... im getti g 15.37.. which am i right in thinkinh thats 15300 or 1530 ohms when set to 20 k ??

Cheers
 
What Racer is saying is there is a possibility you are not turning enough rpm's to produce a good fire...
 
Well i thought that... how would i check? Ive put my multeter on rev cointer for 3 cylinder and checked from wires from trigger and they all saod 320 rpm.... i dont know if checking like that would work though. Also the battery is a freshly charged truck battery so should be ok.
 
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