1975 Evinrude 85 hp locked up?

[skylerjshelton]

I received the motor from a friend. he said it was locked up. i just the starter and wouldnt do anything. so i tilted motor up and dumped wd40 down plug holes and it freed it up a little bit now it turns over slowly. now im thinking of pulling heads off and checking pistons. could anyone out there give me a few ideas to what would be causing it to be locked up. it was sitting on the boat deck for several years. im thinking maybe water in the cylinders? thanks for your time.

 

[emdsapmgr]

Re: 1975 Evinrude 85 hp locked up?

You will be able to see what is going on when you pull the heads. Maybe pull the bypass covers (intake side covers) off each cyl and check the rings to see if they are rusty or carboned up. (or missing)

 

[skylerjshelton]

Re: 1975 Evinrude 85 hp locked up?

i pulled heads off and everything looked good. pulled side covers off and everything looked good. if i take plugs out it turns over just fine. it almost seems like its gettin too much compression. if i put 2 plugs in it turns over a lil faster. but with all plugs in it turns over real slow. so somebody please help. also, i noticed that the plugs that are in there are not the flat style plugs, looks almost like a car plug. should this affect it?

 

[skylerjshelton]

Re: 1975 Evinrude 85 hp locked up?

i took starter off of motor today and took apart to see if maybe it was dragging. so i noticed that one of the brushes was wore down like to a quarter of the rest of them. would that be the problem? it kinda makes since that the start could be draggin. i think im gonna order a new starter soon and go from there. if anything i will just have a spare.

 

[coolguy147]

Re: 1975 Evinrude 85 hp locked up?

clean connection and replace any corroded cables. clean connections too

if no improvement then rebuild or replace starter.

 

[emdsapmgr]

Re: 1975 Evinrude 85 hp locked up?

A strong starter is key to the initial cranking rpm. You need 250 to 300 rpm to fire the ignition. You may want to repair your starter instead of purchasing new. Many times the brushes are all that need to be replaced: you can get them through any BRP dealer. When in there, grease the bushings and clean out all the carbon dust. When you get it to normal cranking rpm's take a compression test. Good compression is usually the sign of a strong engine.