1973 evinrude 50hp

[jims3000]

i have a 50hp evinrude serial 50esl73r the bottom cylinder ha 95lbs of compression and the top has 120lbs the motor does run.is this anything to worry about and if so where can i get piston rings from.i have checked this site and they dont go down to a 1973.also the motor has sat for about a year i got a good deal on it.any info would be appreciated

 

[HighTrim]

Re: 1973 evinrude 50hp

Was it the bottom cylinder that was low by chance? After sitting, I would give it a decarb as described in the FAQ section here on iboats and see if that evens things out a bit. Let us know what you find.

 

[F_R]

Re: 1973 evinrude 50hp

I think I'd be checking that thing for broken rings before running it any more. Pull the head. If that's what is wrong, it will get much worse....very quickly.

 

[tashasdaddy]

Re: 1973 evinrude 50hp

i agree with FR, thats 25 lbs difference.

 

[DJ]

Re: 1973 evinrude 50hp

It could be a carbon stuck ring or a broken one.

Removing the head is very easy, not a bad idea anyway. That way you can have a looksee at the condition of the bores.

 

[samo_ott]

Re: 1973 evinrude 50hp

You might not see a broken ring by just removing the head though. One might have to remove the exhaust covers.

 

[wildmaninal]

Re: 1973 evinrude 50hp

Removing the head will also allow you to inspect the cylinder wall for damage at least sammo.
I agree with DJ.

 

[jims3000]

Re: 1973 evinrude 50hp

does anyone know what the piston bore is for this engine and where to get parts from i have looked online and cant find a place that has that old of a engine.is the bore size the same as newer engines?i dont want to take it apart without getting the parts first,thanks

 

[F_R]

Re: 1973 evinrude 50hp

Bore is 3.060"
Heck, that isn't old. You can view a parts list & numbers, and/or buy parts at crowleymarine.com also buy parts at sea-way.com and ishopmarine.com and laingsoutboards.com

 

[jims3000]

Re: 1973 evinrude 50hp

thanks for the reply

 

[jims3000]

Re: 1973 evinrude 50hp

Bore is 3.060"

or could it be 3.60?