Question about compression...1983 35hp Evinrude

[BlackoutBill21]

So I picked up this total P O S. This guy said it sat for 10 years indoors but it looks like it sat at the bottom of a lake for 10 years. I mean RUST EVERYWHERE! But it might be all rat Pee.

anyway I FINALLY finished hooking up electronics and starter and im getting.... 155 PSI!!!! EACH CYLINDER!

have any of you ever seen that? I mean 150 is like out of the factory brand new type numbers! am I wrong??

any dry too! No oil at all.

I was just wondering If anyone had a crappy motor push that type of number before. or did i do something wrong lol Even I could screw up a compression check.

 

[Bosunsmate]

Mine was way down on that. You may of got a diamond in the rough
It may of had the head planed which can increase compression so dont write yourself off yet

 

[ct1762@gmail.com]

im doing a 1993 30hp. 145 and 143 lbs so these guys are up there (30-35's anyway. my 20hp is around 115-120. different head i think). your guage could be reading high too. my record for compression is my 1986 55hp Nissan... 165 psi in both! at that level, i'd think AV gas wouldn't hurt it lol.

 

[BlackoutBill21]

HA! yeah man all my other motors are in the 90s TOPS! What does it mean to have a head "planed"?
in any case hopefully tomorrow i'll have all my fuel lines and grounds hooked up and Ill know if she runs!

 

[Bosunsmate]

Planed just means that some of the head surface has being removed in order to flatten it, by doing that it reduces the size of the combustion chamber and hence increases compression. There must be a tradeoff but i like power!