Logo
FULL SITE MENU

1981 Evinrude 70 poor acceleration

M

Markhol

New member
I have cleaned my carbs, have good compression....the engine idles fine, after it gets on a plane it builds up speed to about 38mph and runs good from 15-38mph. I checked the spark and it jumped the required 1/2 inch. When I was out today I pulled the plug wires one by one. Each one affected the engine at idle. However, after pulling off the wires on cylinders 2 and 3, the spark gapped from the coil to the engine block. Also, when testing on land I noticed the spark jumping from coil to block when I had the spark checker to far apart. Does this mean Ihave bad coils? Wires? Any comments are appreciated. When I say poor acceleration , It will barely run for about 30 seconds then slowly start speeding up. I have tried squeezing the fuel bulb but did not do anything and tried hitting the choke and that made it bog. This motor is on a 13.5 little bayliner mini boat. It also has a 17 inch prop so it shoud have plenty of spunk. I am stumped.
 
Last edited:
not bad coils but bad spark plug wires, some of these you can replace the wires and some you had to replace the coils. not sure which you have. crank it up at night with the cowling off to see what other wires are jumping to ground.
 
Just to clarify, when I pulled the plug wire from the coil I did not have a chance to ground it fast enough and the spark began jumping from the coil to the block. If I run it at night and there is no spark jumping while all wires intact, would that mean the wires are bad? Also when the spark did gap from the coil to the block, it did so from the side of the coil, not from where the wire attaches to it. Hope this makes sense.
 
Last edited:
Back
Top