25 Evinrude Missing At All Rpm

[macdaddy]

This thing is about to drive me crazy, all new points, condencers,coils, coil under flywheel, plugs,fuel pump, fuel lines, gas tank. But still misses at all rpms. It feels about like a 3 hp motor. My boat is 12 alu. v haul, it weighs about 150 lbs and won't plane out at all with just me (175lbs) and a 6 gal. gas tank.

I have rebuilt the carb twice, link and synk, compression is 125 both holes nice blue spark 7/16" Squeezing the primer ball make no difference, so I think it's electrical???

Help please, before I smash this thing and go buy a new one.

1975 Evinrude 25
Model 25502b

 

[macdaddy]

Re: 25 Evinrude Missing At All Rpm

anyone?

 

[tashasdaddy]

Re: 25 Evinrude Missing At All Rpm

start it at dusk, see if spark is jumping to the block, did you replace plug wires. are you using Champion JC6 spark plugs, gapped at .030. other brands are known to cause misfires.

 

[macdaddy]

Re: 25 Evinrude Missing At All Rpm

I checked the nite thing last night with no spark jump, completley dark.

Yes I am using jc6 plugs gapped at .30.

It seems that it missing on the lower hole, condencer? I have double checked points, they are both set at .20.

This is crazy, I have never had this much trouble with an outboard before.

New wires come on the new coils.

 

[lindy46]

Re: 25 Evinrude Missing At All Rpm

plugs at .030", not .30"
points at .020", not .20"

 

[junior1113]

Re: 25 Evinrude Missing At All Rpm

loose magnets in fly wheel. power pack. coils.or stator about all it could be if plugs and wires are good

 

[ditchen]

Re: 25 Evinrude Missing At All Rpm

I just went through something similar on this 72 25 johnson. Not smooth running, and would start to sound like dropping a cylinder after it warmed up; my case it was he friggen flywheel,, yes the flywheel (see my posted thread).

Question,, did this just start to happen or has been a problematic piece?

Remember, these two strokes are simple.: compression, fuel, spark,, and timing.

 

[macdaddy]

Re: 25 Evinrude Missing At All Rpm

plugs at .030", not .30"
points at .020", not .20"

LOL, yea your right. I just typed it wrong.

 

[macdaddy]

Re: 25 Evinrude Missing At All Rpm

loose magnets in fly wheel. power pack. coils.or stator about all it could be if plugs and wires are good

Magnets are something like made into the flywheel and not loose, I cleaned them well.

Power pack?? Stator?? Plugs and wires are brand new.

Is the power pack the coil under the flywheel? If so its brand new too.

 

[macdaddy]

Re: 25 Evinrude Missing At All Rpm

I just went through something similar on this 72 25 johnson. Not smooth running, and would start to sound like dropping a cylinder after it warmed up; my case it was he friggen flywheel,, yes the flywheel (see my posted thread).

Question,, did this just start to happen or has been a problematic piece?

Remember, these two strokes are simple.: compression, fuel, spark,, and timing.

This has just started to happen.

Flywheel?? The flywheel look good. But anythings possable with this little nightmare.

Yes they are simple, except for this dang Evinrude, I grew up working on outboards and dirt bikes (2 stroke).

I think I have a bad condenser, would this cause this problem?

It will idle fairly smooth but the more gas you give it the worst it gets, full out it sucks and has no power. I pulled both plug wires one at a time and found the miss to be on the lower hole, now what?

 

[kenmyfam]

Re: 25 Evinrude Missing At All Rpm

Replace condenser is a cheap and easy one. How are the working surfaces of the points ??? the "hill and valley" thing can cause major issues if they have been adjusted or disturbed. If the surfaces have been re-stoned several times you may be through the case hardening and into soft material. This will cause no end of running issues.

 

[ditchen]

Re: 25 Evinrude Missing At All Rpm

Have you pulled the plugs verify it is only the bottom cylinder? Have you verified the point faces yet as mentioned?

I have bought new OMC/BRP condensers and points and got a new defective condenser more then once. You can always swap between cylinders.

 

[macdaddy]

Re: 25 Evinrude Missing At All Rpm

Replace condenser is a cheap and easy one. How are the working surfaces of the points ??? the "hill and valley" thing can cause major issues if they have been adjusted or disturbed. If the surfaces have been re-stoned several times you may be through the case hardening and into soft material. This will cause no end of running issues.

Hill and valley thing?????

The points, condencers, plugs, coils are all brand new.
I will switch condencers today and see if that helps.

 

[tashasdaddy]

Re: 25 Evinrude Missing At All Rpm

make sure all your connections are clean an tight. you do not have power pack, stator, etc., you have a magneto ignition. the simplest there is. one problem i have had is making sure the coils have a clean ground, to the block. you could have a bad spark plug.