1990 evinrude 140 loses power

[Livinshallow]

For the past few months my motor would run perfect and then suddenly lose power and then come back on. It loses power just enough to be jarred foward briefly, it almost feels like your hitting bottom. This usually happens at higher rpm's, sometimes it doessn't do it all day. I checked the water separator and it is clean. I'm thinking electrical, possibly power pack going bad, any suggestions.

 

[reeldutch]

Re: 1990 evinrude 140 loses power

sound like your loosing a cylinder.

is this a intermitted problem?
or does it always happen at the same rpm?
does it happen suddenly and comes back on suddenly?
does it sputter?
how many rpms does it drop at the rpms your on?

if you are dropping 1 cylinder we have to verify wich one it is.

 

[Silvertip]

Re: 1990 evinrude 140 loses power

Before spending money on high-buck parts, why not eliminate the simple stuff first. If it's a very sudden loss of power, like you shut the key off momentarily and then turned it back on again, that points to electrical. If the power loss is gradual slowdown, that points to fuel. When it dies down, squeeze the primer bulb a few times to see if it picks up. If it does, there is a fuel problem. That can be due to things as simple as a kinked fuel line. A fuel restriction such as a partially clogged fuel pickup in the tank is another possibility. A fuel pump going bad is another. If the fuel system checks out, then investigate ignition.

 

[Livinshallow]

Re: 1990 evinrude 140 loses power

Thanks for the replies. The motor does this suddenly and never predictable. It is a SUDDEN quick loss of power and the power returns instantly. It happens usually at 3/4 to full thrittle sometimes when getting on plane. I know this is somewhat vague but I think it is more an elect issue than fuel.

 

[mikesea]

Re: 1990 evinrude 140 loses power

check all the connections to and from the coils.look for cut or rusty ended plug wires,be sure the grounds for coils are clean and making a good ground connection,be sure to check the smaller wires on the coils too

 

[reeldutch]

Re: 1990 evinrude 140 loses power

also dont rule out the ignition switch.

 

[JMO]

Re: 1990 evinrude 140 loses power

It sounds like your power pack or stator one way to check is if it happens at 4000 to 4500 rpm and backs done about 500 rpm and then go back up power pack if it has a pwer loss of more than 700 to 1000 rpm then it can be your stator do not rule out coils but the coils u will feel a stumble not just a smooth power loss again its a stumble if its a coil u will know what i mean when i say stumble also when the power pack is bad when u first warm up u can go full out for about 2 may be 3 min a stator it will allways do it

 

[Walker]

Re: 1990 evinrude 140 loses power

Are you sure your clutch dog isn't skipping on the gear?? Doesn't sound like any ignition part, but could very well be a bad ground or wire somewhere.