1973 Evinrude 65hp power loss

[magicnov]

I was out yesterday and and all was fine until I was idling, and my motor conked out (this happens fairly often at idle speed). I had some difficulty restarting, but after numerous attempts and by pulling out the choke (my solenoid doesn't work so I do this manually), I was finally able to get it going. All was fine for awhile, until I noticed a dramatic loss of power. It was then, that I realized that I had been cruising with the choke still out. When I pushed the choke back in, I still couldn't get back to full power. I'm thinking that perhaps one of the plugs got fouled or something, but I really didn't hear any difference in the sound of the engine. Also, I noticed that my coils look kind of ratty and one is rusted. How can I determine when these should be changed and should all three be replaced at the same time? Any suggestions or thoughts would be much appreciated.

Thanks,
David

 

[jtexas]

Re: 1973 Evinrude 65hp power loss

Get yourself an inline spark tester (couple bucks at autozone), set the gap at 7/16", clip it to the engine block, attach the spark plug leads (one at a time), and look for a sharp blue spark while somebody turns the engine over with the key. All plugs should be out, and the other two leads need to be grounded to the block for this test.

Bad spark on one or two, swap it with a good coil & retest -- problem follows the coil, replace it. Problem stays with the cylinder, you'll have to troubleshoot the timer base.

Or, the manual gives resistance specs for testing the coils with an ohmmeter.

From your description though, sounds like you are just about due for a carb rebuild. Choking a warm engine should flood and kill it.

 

[magicnov]

Re: 1973 Evinrude 65hp power loss

Thank you for the tip. So I connect the tester to one lead and I ground all three. There are no plugs used during the testing as the coils should create a spark that is visable through the tester window. Is this correct?

David

 

[jtexas]

Re: 1973 Evinrude 65hp power loss

you got it -- if you have a fancy tester with a window -- mine just has an open gap. If you're handy, you could make a tool for testing all three at once, piece of wood & some hardware...........