im pulling my hair out... :(

[DJENAN]

Hi, I have a 1979 mercury 70hp , which was running great until the other day it just wouldn’t start, upon doing a spark, fuel compression check, everything was ok apart from one spark plug had a major crack on the ceramic area exposing the electrode. I replaced it and it still wouldn’t start.<br />So I then took it to my mechanic and he spent 3 hours on it and thinks it could be a timing module that sits near the stator under the flywheel, which has caused the ignition timing to be thrown completely out of sync. Does this sound right to u or is he pulling me chain as I have only used him once for a service.<br />Anyways he is going to call me tomorrow when he sources a second hand timing thingo and trys it out.<br /> <br />Any input would be greatly appreciated.

 

[NEECAPRS]

Re: im pulling my hair out...

Obviously, this problem has some pretty smart people completely speechless! If it really has good spark(1/2"+,blue flame)but at completely the wrong time, it should also be making belches and other assorted strange noises when you try to start it. Are you hearing that?

 

[Gold Bear]

Re: im pulling my hair out...

DJENAN <br /><br />Two questions come to mind.<br /><br />1) Which spark plug was broken? Was it the top one?<br /><br />2) Have you struck anything in the water lately, that might have caused the engine to stop suddenly?<br /><br />Just a thought. A broken crankshaft is the only thing I can think of that might result in a broken spark plug and incorrect ignition timing for your engine.<br /><br />Regards,<br /><br />Gold Bear

 

[jim dozier]

Re: im pulling my hair out...

Check for a sheared flywheel key.

 

[Kenny Bush]

Re: im pulling my hair out...

Man.... that does sound tricky. I have never heard of a timing module on anything that old. Does your motor have the thunderbolt breakerless ignition? If you are getting spark and fuel, that motor should crackle and pop regardless of timing..... If you are getting spark to all plugs, then get a timing light and check timing. Then check for spark pulse on each plug(with the timing light). A lot of cases involve the little rubber distributor belt breaking or jumping a tooth or two. Anyway post back with results.

 

[DJENAN]

Re: im pulling my hair out...

well he still hasnt sourced a new timing trigger, its thunderbolt ignition. According to my manual the resistance checks for the trigger are ok but the stator and rectifier were wrong. <br />When i turn it over it doenst crackle ot belch or anything , its like the spark plug leads have been disconnected. <br />i have not hit anything in the water at all and the spark plug that cracked was the bottom one and only the white ceramic area was cracked.<br />Its got me stumped and im taking it to a different mechanic on saturday who specialises in old merc. Over the phone he said it must be the stator or switch box but he will test it on saturday.<br />I took the stator off my self and it has a slight varnish leak on one spot and have been told it is the original one and never been changed.<br />Also i dont think i have any rubber belts on my motor , well not that i can see