'78 Merc 50, spark & fuel but won't even cough

[ledgefinder]

Need some experienced advice on a 1978 Merc 50hp, please. It has the switchbox & 4 coils. I bought it with a dead switchbox, replaced same, and cleaned the carbs. At that point, I could rope start it, using no controls. I would manually set the throttle arm so that the spark arm was back against it's stop, then quickly pull it forward a bit, once it started, to keep the revs down. Seemed like it idled OK at low rpms, but would die suddenly if I pulled the spark arm too far forward.<br /><br />Hooked up the controls and, using the electric start, haven't been able to get even one cough out of it. There are identical sparks coming from 3 of the plugs anyway (haven't pulled the bottom one). If I bend an electrode back, the spark is strong enough to jump from the center electrode to the threaded outer shell. I have tried starter fluid in the carbs, and fluid & premix directly into 3 of the 4 plug holes. Not even one chuff so far. <br /><br />I 'think' the spark is hot enough, and assume this is a timing problem. I've disconnected the throttle cable & tried it with the spark arm all the way back, though & still get zip. <br /><br />Any clues here?<br /><br />Thanks, ledgefinder

 

[johnnyv]

Re: '78 Merc 50, spark & fuel but won't even cough

I am not that experienced but have you tried johns old merc web site? they are at http://www.pfs-ware.com/ go to johns page there are very helpfull people there! most of what I have learned is through them!!!hope you get her running!