Home › Forum › Ask A Member › "Newer" 25/35hp OMC compatibilities › Re: "Newer" 25/35hp OMC compatibilities
In my opinion you are going to need every fastner you have on the earlier motors! Why do you think OMC went to more on the newer blocks? I don’t think the aluminum plate will be too good because aluminums expansion rate is more than stainless steel. The tap can be gotten out, but requires drastic measure of cutting the side of the hole out and then welding the hole up and re-drilling. Best done with a mill for the re-drill. This can become more than you want to spend unless you just want to try with the block for learning purposes. While it was in the mill (if you went this way) it would be nice to deck the side of the block. Trueness would be nice while you are there. You did look to see if you had sleeve separation while you had the head off? I know you had the head cover off because you said you ran it without a thermostat. You should have piston damage with sleeve separation, but compression on pressure back rings is not a good way to tell. With both the exhaust and intake covers off you should see something. This is a siamese cylinder engine (no water between cylinders) so they score at top and bottom of the pistons. Just something to remember. If it runs good maybe you have gotten away with the past over heats. Sending you some pics of a tri-toon pontoon from FL while at the meet down here.
Dan in TN