650 Mercury 1975 - no fire

mwbaughan

Seaman Apprentice
Joined
Nov 14, 2002
Messages
47
Guy rebuilt it for me last year. Shut off when breaking in. Started again after cooling down and ran good till hot again. Started one other time at home. Getting fire to plugs is hit or miss. What order should I follow to trouble shoot? Thanks!
 

mwbaughan

Seaman Apprentice
Joined
Nov 14, 2002
Messages
47
Re: 650 Mercury 1975 - no fire

no fire at all now, all I have is a stadard test light, could it be ignition, neutral safety, coil, switch box? what order / method to check?
 

mercuryblues

Seaman Apprentice
Joined
May 9, 2003
Messages
37
Re: 650 Mercury 1975 - no fire

when you say you are getting no fire do you mean that your engine is turning over and trying to start but there is no spark at the plugs?Or when you turn your key is it like a dead battery?I have the same motor only a 1966 and I have a manual and can tell you the steps if you answer my question.
 

mwbaughan

Seaman Apprentice
Joined
Nov 14, 2002
Messages
47
Re: 650 Mercury 1975 - no fire

It turns over nice, but no fire at the plugs.<br /><br />Thanks......Mark
 

mercuryblues

Seaman Apprentice
Joined
May 9, 2003
Messages
37
Re: 650 Mercury 1975 - no fire

ok 1.make sure battery is fully charged and check connections at battery and coil.Then recheck for spark at plugs if no spark most likely in ignition system.To check coil 1.unhook negative battery cable 2.disconnect negative and positive leads at the coil terminals 3.disconnect the high tension lead from the coil tower 4.set the ohmmeter on the RX1 scale and connect its leads between the coil negative and positive terminals the reading should be 0 5.set the ohmmeter at RX1000 scale connect the leads between the coil tower and either the positive or negative coil terminals it should show no continuity If the readings are not as specified replace the coil.After you do that get back on here with the results and we will go from there Good luck
 

mwbaughan

Seaman Apprentice
Joined
Nov 14, 2002
Messages
47
Re: 650 Mercury 1975 - no fire

thanks, it will be midweek before i get a chance <br />i hope it is only the coil! will get back on wednesday or so, thanks again!
 
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