I am working on a 1973 9.5 Evinrude Sportwin. When I removed the old spark plugs, I noticed some exsessive discoloration or perhaps fouling on the bottom cylinder cover. Is this a red flag of some problem or can this be considered normal?
I just got this motor and it was like this. I am am doing some basics before trying to start it. I borrowed a compression testing kit from the local O'reilly's Auto but the compression tester turned out to be broken and thats the only one they had! Anyway, while I wait for them to have one sent from another store, I put my fingertip in each of the spark plug holes and had a buddy pull the starter. The pressure from the engine pushed my finger out with pretty good pressure from each one. At least I know it has some compression. What kind of numbers am I looking for? I read somewhere on here that I need at least 70.
I havent started it yet so I am not sure about the water pump. I think I'll replace the impeller no matter what. (If I get good compression) My newest problem is no spark. When I first got it, I tested for spark and got 1 from the top plug but not the bottom. Now I'm not getting a spark on either! I guess i need to figure out how to troubleshoot the magneto and points. LOL
We had a fellow posting he was getting 30 each cylinder and his was running! You sure don't need 70. I honestly think the 9.5 must have been a lower compression engine because of the readings many have posted. I have a 73 and she runs like a top but I never use it. My bad. Best of luck. Rick.
Success! The motor started after being stored outside for years. I replaced the ignition coils and spark plugs, rebuilt the fuel pump and carb and it started up on the third pull! It keeps dieing if I let it idle but I hope thats just some minor adjustments. Thanks to all for your help. Leeroysramblings.com helped a lot too.