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| 50 hp mercury 1983-ish, no spark |
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Message |
    
daniel pellan
New member
Username: crazy
Post Number: 1
Registered: 05-2009
| | Posted on Saturday, August 08, 2009 - 02:49 pm: | 
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I can't get a spark anymore, I just bought the motor, the guy I bought it off of said that it had been sitting for about a year. I went over it, cleaned up the starter bushings, little things like that. it started ran good, water pump worked good. but it seemed a little slugish. I thought that it just needed to run for a little bit. I installed it on my boat. had to wire in an older style 6-point harness. I took it to the lake, it ran good but it seemed like it just couldn't fully wind out. as I was load it back up it stalled and hasn't started since. I pulled a plug and can't get a spark. I've checked everthing I cant and now I have no idea. does anyone have any ideas on what to look at? |
JB
Senior Member
Username: beckerjs
Post Number: 1820
Registered: 11-2005
| | Posted on Saturday, August 08, 2009 - 02:57 pm: |
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remove the harness and jump the starter relay, check for spark or....remove the black/yellow wire on the switchbox, that grounds the ign, check for spark.
Remove and clean the carbs if the engine still has compression, yes check the compression.
Your engine is really 2 engines stacked on top of each other, if one carb is plugged it will run on 2 cyl's. The other 2 are going for a ride on the crankshaft with no gas/OIL. So check the compression first, then fix it if its not to late. PS that bottom plug can be gotten to by removing the 4 stainless bolts on eithe side of the lower cyl, and the the ones up front. Its a Beotch. |
daniel pellan
New member
Username: crazy
Post Number: 2
Registered: 05-2009
| | Posted on Saturday, August 08, 2009 - 03:29 pm: |
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I checked the compression when I first started it up. the top three had about 70 psi, if I remeber correctly. the bottom I couldn't get the tester on but when I put my finger over it it pushed my finger off. the top three also had a slow leak down. I think I have already tried the black/yellow wire thing but I will doulbe check that. I have had the harnees off and nothing. I just had the carbs out and they were both clean. i thought it might be my tilt switch so i took that out of the question and nothing either? |
JB
Senior Member
Username: beckerjs
Post Number: 1821
Registered: 11-2005
| | Posted on Saturday, August 08, 2009 - 03:57 pm: |
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click on general troubleshooting and also merc specs
http://www.maxrules.com/fixignitionspecs.html
70 psi is not enough, check your gauge for calibration
removing the black/yellow also takes the mercury switch out. If still no spark, trigger, switchbox or stator is bad. 2 of those are not cheap, along with 70psi this doesn't look good. |
rick riddle
Member
Username: rickriddle
Post Number: 6
Registered: 06-2006
| | Posted on Tuesday, August 11, 2009 - 04:06 pm: |
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you need a DVA to check your voltages from the stator. If the stator checks out its probably just the switch box. Also look closely at all the wires. You could have a wire breaking down on the stator or trigger, i find this a lot working on older engines. Check for continuity with a meter over the full length of all your wires. |
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