1974 evinrude 25hp problems!

[ky_pits]

I just recently purchased a 1974 Evinrude 25hp.It has had new points/condensor,plugs,fuel pump kit,a fresh rebuild on the carb.Sounds good right,Its not.It will only run on 1 cylinder.The upper cylinder is warm to the touch while running where as the bottom cylinder is hot.It has no power whatsoever.I replaced the coils on both cylinders,it did not help.Pulled the flywheel and double checked points,set at .020.I have a 10 hp merc that will run all over it.I'm waiting on a manual.I'm getting very aggravated at this dang thing.Any help would be greatly appreciated.Oh compression on both cylinders is 115# Thanks

 

[JB]

Re: 1974 evinrude 25hp problems!

Howdy, ky-pits.<br /><br />Have you tested both cylinders for spark?<br /><br />It is embarrassing how often wholesale replacement of parts that aren't broke causes problems. That phenomenon is the mother of the wrench's advice about "If it aint broke, don't fix it." Too late. Now it's broke.<br /><br />Your best bet is to wait for the manual so you have an idea what you are doing and what to look for.<br /><br />There is only one carb. Very likely not the problem.<br /><br />There are seperate reeds, bypass covers, magnetos, coils, and spark plugs. A sixpack of Heineken says it is one of those causing the trouble.<br /><br />Good luck.

 

[ky_pits]

Re: 1974 evinrude 25hp problems!

Thanks JB,Checked spark by pulling plugs and attaching boot and laying it on the head.They both had spark though not real blue,more red than blue.After that i put plugs back in started itr and pulled plug wires off one at a time and the top plug wire made no change after i pulled it off.The bottom however killed the motor after i pulled it.....Guess i'll wait on the manual....I'm losing valuable fishing time!! Thank again for the help

 

[rwcreigh1]

Re: 1974 evinrude 25hp problems!

i would try to pull the reed plate and check or just replace them.good luck

 

[Paul Moir]

Re: 1974 evinrude 25hp problems!

Try to rig up a test to see how far you can make each spark jump. If you didn't get the wires screwed all the way into the coils, they may be arcing over underneath. Also, if the points arn't spotless, it won't provide much of a spark. Even new I clean them.<br /><br />Until the manual gets there, tighten the flywheel nut to 42ft/lbs, or you'll be shopping for a new flywheel key too.<br /><br />EDIT: I was thinking of the earlier ignition system with that plug-wires remark. Do run the test though - you should be able to produce sparks 3/8" long.

 

[fireman57]

Re: 1974 evinrude 25hp problems!

Paul is right. I had a tough time seating the wire in the new coil for a 76 35hp johnny. Took eight or nine tries. Thought the coil was bad. Put toothpick in the coil without the wire in it. Measure the distance that it goes in. Make sure you get the plug wire in that far and above all make sure that the center does go on the post in coil. I found that I had to "screw" them in to get them to go in as far as they should. I do wish that Bambardier would sell these already assembled and tested.

 

[ky_pits]

Re: 1974 evinrude 25hp problems!

thanks for the info.I'll check all that stuff as soon as the weather breaks.The motor supposedly ran fine before it was shipped from Mississippi.I'll check all my connection as well.Thanks again

 

[Chinewalker]

Re: 1974 evinrude 25hp problems!

How is compression? Any evidence of water on the plugs? Could be a blown head gasket...<br /><br />- Scott

 

[ky_pits]

Re: 1974 evinrude 25hp problems!

compression on both cylinders is 115# and no evidence of water on spark plugs.One thing though is I notice water in the cowl area after it has been running ,dont know if its splashed up there cause I havent had the hood on it yet while its running??

 

[ky_pits]

Re: 1974 evinrude 25hp problems!

well I think I got figured it out.Did a spark test today and everything was fine there,it would jump 7/16inch.Put the (new)plugs back in and the other cylinder wouldn't fire.Took the plugs back out and switched again and the other cylinder wouldn't fire.BAD plug.The whole time its been a bad plug,just figured since they were new they were good,guess not.Thanks for the help,I'm going fishin'

 

[fireman57]

Re: 1974 evinrude 25hp problems!

Catch some for all of us.