1972 Evinrude 85 hp misses at WOT

[jdubb1000]

I have recently bought a 1972 evninrude 85 hp motor. The motor runs like a champ in neutral with no load on it, but as soon as you put it in gear (electric shift) it cuts off. If it does get going, it gets very little RPMs and spits and sputters badly. I have just had carbs cleaned,points adjusted, new spark pluge and fresh gas/oil. Please Help! P.S. I have heard that this motor requires a special lower unit oil (because of electric shift) if so what kind? Thanks for your help!

 

[JB]

Re: 1972 Evinrude 85 hp misses at WOT

Howdy, JDubb. I think you are losing a cylinder or two. Those V4s can idle like a kitten and roar like a lion on two or three cylinders with no load on them. If they lose a cylinder or two they croak as soon as you ask them to do a little work. Sound familiar?<br /><br />Fire her up. carefully remove each plug wire, one at a time. If the engine drops rpm or dies, that was a good cylinder. If there is no change, that cylinder is not making power. See if the plug wire from a dead cylinder will make an arc to the block; should jump a good 1/2".<br /><br />If the two top, or the two bottom cylinders are dead, you may have one bad carb.<br /><br />I don't have the manual on your year engine, but if you have one dead cylinder or both on one side it is likely to be an ignition problem. Try swapping parts between cylinders and see if you can get the trouble to switch cylinders.<br /><br />If you haven't found it yet, get back to us with what you have learned and we'll pick it up from there.<br /><br />Red sky at night. . .<br />JB

 

[jdubb1000]

Re: 1972 Evinrude 85 hp misses at WOT

Hey thanks J.B. for the help. I've got spark at every cylinder and each plug seems to be firing well. One "part-time mechanic" looked at it and said the rotor button was cracked and had a hole in it. What do ya think? What about timing? Thanks again!

 

[Dhadley]

Re: 1972 Evinrude 85 hp misses at WOT

Yes the most likely place for a miss in that engine is in the distributor cap rotor area. They were good about forming carbon trails and giving you fits. Also check the anti-reverse spring while you're there. <br /><br />The lower unit is a hydro-electric shift unit and requires Evinrude/Johnson Premium Blend lube and needs about 27 ounces.<br /><br />Good luck!

 

[sandy]

Re: 1972 Evinrude 85 hp misses at WOT

Don't know much about a 72' OMC 85hp, but<br />if it has a Power-Pack or something similar,<br />I'd go there next. It sure helped me.<br />Good luck.

 

[bigkeebouskie2002]

Re: 1972 Evinrude 85 hp misses at WOT

my father has a 1978 85hp evinrude it ran like a champ almost all last summer late in the season it started boging down at wot if you keep it at about 1/4 throttle it runs smooth but when we try to tube it will power up then bog down power up then bog down again over and over again sometimes it will run fine for awhile then act up again any ideas thanks for any help