1978 mercury 70hp starting problem

[white mach1]

I have problem starting my motor in the early morning. It doesnt fire at all. About an hour or so after I trowl out with the electric. I turn the key and the motor will start. Im thinking its a moisture problem.<br />I did a ohm check on trigger and stator and it falls within specs. (tested during the day and the early morning) Im thinking its the switch box. A while back I had it looked at by servicetech and he put a used switchbox in. I had other simuilar problems and i took it back to him. He tested it for spark and it had spark on all three cyls.<br />After a period of time i put orginale one back in. (the one that doesn't start in morning) Now, Iwanted to see what the used on did so i put it back in and it would start<br />in the morning but when i wanted to speed up it had no power, like cylinder dropped out. Is buying a new switch box the answer? $193 for a new one. Thanks for any help, Rick

 

[clanton]

Re: 1978 mercury 70hp starting problem

I think you realy should check all of the output voltages with a DAV meter or peak reading meter. Checking ohms is checking system unloaded, and only part of complete system check. See WWW.esitest.com for meter or adapter.

 

[JB]

Re: 1978 mercury 70hp starting problem

Howdy, Mach1. Some cool, damp morning try your misbehaving unit. Then put a hair dryer on it long enough to warm/dry it and try it again. That should prove your theory, with which I agree. <br /><br />If that works, take it out and put it in the oven at about 150 degrees for a couple of hours. Cool it and give it a good waterproofing. If the problem is moisture that should fix it, if the problem is temperature it wont, but it seems worth a try.<br /><br />Good luck and keep us advised of anything new.<br /><br />Red sky at night. . . <br />JB