1965? Mercury 650 no spark

[senecalaker]

I hope someone can help. I have a 1965? Mercury 650, 65Hp. ser.# 3156568 on a boat that I just bought. I've always had I/O's in the past and don't have much experience with outboards. My problem is that the motor turns over freely, but I have no spark. I've changed the plugs and wires, but that's all I wanted to get into until I've received some direction from someone more knowledgable than myself. Any ideas? Also, I am assuming this was a 50:1 gas oil mix engine. Am I correct?

 

[Laddies]

Re: 1965? Mercury 650 no spark

Yes it's 50 to 1. has the engine a mag or CD ign they were both availably to 72 I think CD has 3 wires from the dist. and mag has only 1 attached on the mag

 

[senecalaker]

Re: 1965? Mercury 650 no spark

There is 1 wire coming from the dist. cap (other than the 4 plug wires). I know it's a thunderbolt ignition, if that helps at all.<br />Thanks for the oil ratio info.

 

[Laddies]

Re: 1965? Mercury 650 no spark

First ck to see if there is 12 volts to the white termenal on the 4 wire side of the switch box with the key on. the red is hot all the time,on the other side of the box, 3 wire side, hook a jumper wire between the brn and white termenals, with a jumper wire hooked to the blk termenal touch the wire to ground every time you arc it the coil should fire. If it don't the box is bad- if it does ck the drive belt and if it's ok then the trigger is bad. I have never seen one of those coils go bad---Bob

 

[senecalaker]

Re: 1965? Mercury 650 no spark

Thank you for your help. I'll try it first thing in the morning when I get out of work.<br />Thanks again !!<br /><br />Mike

 

[senecalaker]

Re: 1965? Mercury 650 no spark

I found the CD box to be bad. My local marina contacted Merc. and they said the box is no longer available. Any idea where I may find one? The engine serial number is 3156568 and the number on the box is 087741. Is that the merc part number?<br />Thanks,<br />Mike