1979 Evinrude 140 140943R Electrical/Ignition Circuit Question - 20A Fuse

[scott hamilton]

[FONT=&quot]Motor has always ran really good but a little cold blooded and sometimes would die moving from neutral to forward idle. So, I took it to have timing, link/synch and had carbs checked out to see if it would run better. Shop adjusted floats saying that the float level in this model is extremely sensitive. Also, adjusted timing. Ran great first time out after shop (prob 2 full hours of run time). Yesterday ran great for first 30 minutes. Then cruising at about 4500 rpm motor seemed to drop a cylinder (like it had a fouled plug). After a few minutes it came back on and ran great again for 20 minutes. Fished for 3 hours. Went to start and motor turned over but no fire at all (this motor had always at least fired/popped). Cranked it for a few and decided something was definitely wrong. Tilted all the way up to have a look. Removed plugs and all were wet and didn't appear fouled. Tilted back down and turned key. No power at all to anything. Changed the little 20A fuse. Turned key and fired right up and ran great the entire trip back.

1. Does the little fuse have anything to do with the ignition circuit?
2. Or do you think I had (and have) something else intermittent going on?

Thanks for all your help.[/FONT]

 

[racerone]

The spark ignition on that motor is looked after by the magneto when flywheel is turning above say 250 RPM.----The 20 amp fuse has to do with running things like cranking and choking the motor.-----A compression test is a good thing to do on that motor as they do have a history of breaking the piston rings.

 

[scott hamilton]

Thanks for reply. I guess I'm just hoping nothing is lurking in this old but great motor

 

[scott hamilton]

Ps. Compression good on all 4.

 

[emdsapmgr]

The engine does not need a fuse to run, only to activate the starter. If it ever blows, take the one out of the power trim control box. It's the same one and you probably can get by with no trim to get home.. Better still, buy a spare. A missing plug could be one plug dropping spark. (an ignition problem.)