evinrude heads

Will the heads from an 85 115 Johnson fit my 86 110 Evinrude? They seem to have a smaller combustion chamber that would increase compression.

Re: evinrude heads

BK yes they should fit.. what you might have to do is to rejet your motor slightly richer, for the added compression rise! but the only way is to test! if you want to make that thing slightly more powerfull, install some 1 3/8" carbs on there.. i think you have 1 5/16".. just for some spare time playing!! <br /><br />good luck<br /><br />SP

Re: evinrude heads

Thanks for the reply Scale. I putnew rings in this motor and don't want to have a problem with the piston slapping the head. Does anyone know the clearance between the piston and head? The pistons seemed to bump the head on the left side without gaskets installed while I was assembling the motor. I don't see that now with the gaskets in and heads torqued, but the motor is not flying at 5000+ RPM. All other replys would be welcome before I fire her up soon. Thanks in advance, Brian

Re: evinrude heads

BK.... The heads will fit of course, but are not compatable. I strongly suggest that you avoid that interchange.

Re: evinrude heads

BK '68 <br />If the pistons touched the head with no gaskit while cold, what happens when it get warm!<br />Just a thought.<br /><br />Richard

Re: evinrude heads

Before you rebuilt this engine what was the RPM before? are you sure that the pistons are installed correctly? are the carbs clean? correct max timing 26-28BTDC? same prop? if all are yes then it should run great. don;t forget to break-in!..<br /><br />good luck<br /><br />SP

Re: evinrude heads

I'm with Reeves on this one, you need to always measure bore opening of the heads and CC them for size, If a rookie can see the size difference at a glance it sounds like to me that you might have a set of high-elevation heads or even the wrong bore size, I have seen a customer accidently put the 3.375 heads on the 3.500 motors, just because there all V-4 cross-flow motors don't mean there all the same. Good luck.

Re: evinrude heads

The heads are from a motor I got for parts. I am using the the best pistons and rods from the two motors. They are both std. bore with the same casting numbers. I have rebuilt motors for years when needed. The heads are easily noticed as smaller chamber heads. I was just wondering if the piston to head clearance is that close that it would interfere without the gasket installed. I was thinking that the deck height of the 115 was taller for some odd reason? I am about to install the cooling hoses and fuel lines in hopes of breaking her in soon. I am planning on premixing the fuel at 50:1 and using my VRO for the first tank or two. I was also thinking of using a portable tank to insure fresh fuel. My tank has some fuel from last year I will need to divert to my truck. I appreciate all the suggestions. Brian

Re: evinrude heads

Finished hooking up all hoses and decided to fire her up. She cranked over in under 5 seconds. Idled nice and smooth for 10 to 15 minutes. Tommorow I will drop her in the water and run her at half throttle for an hour or so then bump her up for a bit. Tachometer is not reading correct. Not sure if battery is charging yet. Hope to see a voltage increase when i raise the RPM's. Hearing her purr again has got me happy again.

Re: evinrude heads

Put her in the water and she started and ran great.... After 20 minutes turned around to go hit fishing hole... After a bit she dropped a cylinder ... I didn't want to shut down in the CD canal so I limped home ... alot slower than the 30-40 I was hitting at first ... got back to dock and felt one bank hotter than the other ... pulled the plugs and found both wet fouled ( from limping home) ... went to pull plugs from colder head and noticed coil wire off ... connected and motor fired up much better ... will buy new plugs and hope she runs as good as the way out. I did do a finger check on compression to make me feel a little secure. All seems well.