Ok, so I bought the motor a few years ago and it kept getting jammed when trying to turn it over. It turned out that one piston was completely coked up and kept jamming in the cylinder. So, to go cheap, I just replaced the rings on that piston and cleaned all the pistons of any carbon. I'm not a professional mechanic so I can't tell if a cylinder is out of round since I don't have the tool. Anyway, it is reassembled and it?s been good so far but idling has been a bit of a headache. I decided to run a compression test on it and it turns out that the #4 cylinder, the coked one, has about 15 psi lower pressure than the rest. Now that summer is just around the corner, I want to take it apart again and rebuild it. I've read on here that you can take a small bore and bring it up to big bore specs. According to the posts, all I have to do is bore it to 3.6855 and change the heads. I was wondering though; do I need to rejet the carbs too? I would assume so because of the larger displacement and also since the Evinrude web site says they are different. Also, I was going to listen to Dhadley and find a set of 1993+ connecting rods to help with the idle. Is all this worth the effort or should I just rebore to .020 oversize and call it easy? I plan on keeping the motor for some time and there is no big rush on the rebuild since I got a spare motor (1979 115) in my garage. I?m just looking for some helpful hints before I go through with the rebuild. What else would I need to create a big bore V4? Thanks.
