Ok so I finally broke down and split the case on my 1977 Johnson 70 horse as some of you already advised. I was redoing the exhaust manifold gaskets and found rusty water in the exhaust ports and I could see the scored pistons so I tore it down. It doesn't look pretty to me but it's been a long...
I am tearing the whole engine down. The head was straight before when I had it off but I will check it again. If I repair the engine I will assume it is warped and resurface it anyway.
I need to apologize to Racerone and F_R. You guys were totally right about the engine having internal issues. I was stubborn, acted like an ass and made a fool out of myself. I should have listened to you guys from the start.
I found a parts motor for $100. I pulled the exhaust manifold/plates...
The first told me to throw away the motor and buy a new one without actually even attempting to get down to what the problem is. The second basicly told me I was an idiot and to go buy a 4 stroke that can do all the thinking for me. It doesn't really feel like a loss to me for some odd reason...
It's 120ish PSI COLD. You're going to sit here and tell me compression is 100% the entire problem? We are going to have to agree to disagree. There are no plastic bearing cages inside of the engine that I am aware of. No lateral movement of the flywheel and the piston pins feel tight. Have I...
Yeah, IDK, around the intake ports between the carb plate and the reed assembly they were soaked and I could smear the gasket material with a finger.
I am very stubborn when it comes to stuff like this. I won't quit until I find what exactly is causing my issues and determine it to be...
You may be right. I just don't like to be defeated until I know without a doubt I am defeated you know? At the least I'd like to know why I am defeated. I looked at the pistons through the exhaust ports though and they looked good. The cylinders looked good too. No scoring at all. I suppose...
I made a new post that summarizes everything that I have fixed and found wrong with this engine. I describe the overheating and compression tests there. 120 isn't terrible for a 43 year old engine. I really don't feel like compression is my main issue.
I have made a few different threads about various stages of my struggle with my boat motor. I made this post to compile all of the information together and hopefully get this figured out (like the on-my-knees-begging kind of hopefully).
Ok, this post is going to be a long one so buckle up. If...
Ok so here’s an update…. I took the boat up north but the day before I left I bought three new coils and swapped them out. The old coils tested way out of spec or didn’t test at all. I also was spraying carb cleaner around my intake manifold gasket with the engine idling “smoothly” and the motor...
I read up some more on the testing and I am 99% positive I was doing it right. I took all three coils off. Put the black test lead on the coil ground wire and the red inside the spark plug socket and got no reading on one and the funky reading on the other.
