Sorry for the long post in advance.
I bought a jon boat (duracraft 1542) recently and it came with a 1985 yamaha 25HP tiller. Wanting to have a side console, I also bought a 1996 Yamaha 30HP (C30ELRU). It is the commercial 2 cylinder and has a single carburetor. Seller only wanted $650 for the listing. Came with control box and shift cables. He also said it only needed a carb job and spark plug change. He did some work and changed the CDI box. He also took the head off to see if there was any damage. Apparently there wasn't any. Said it was flooded before from the seller he bought. He didn't try running it and gave up because he wanted to buy a new four stroke. Willingly, I bought the outboard no questions asked. I didn't have a compression tester on me and the pull start felt like it had decent compression.
Took the carb off and cleaned the jet. Changed the spark plugs. Inspected the lower unit, and it had a brown color? It wasn't milky so the seals weren't blown I hope. I've used a brake tester, and the pressure stayed at 10psi. So lower unit is good. Hooked it up to the gas tank and battery. Turned the key and nothing happened. Sometimes I would get a click that kept repeating from the starter relay. I think it may be a battery related issue or bad connections. But the connections looked fine. After fiddling around, I got the starter to spin the flywheel. Maybe it was a bad connection. It took several tries to get it running but then it would stall after a few seconds. It would only run if I had the choke on and the high idle lever pulled out. And obviously, it is revving at high rpms. If I tried to lower the idle lever or choke, it would stall.
I waited a couple days because currently the weather is unbearably hot. I bought a compression tester from BlueDriver. (Harbor freight has bad reviews). The top cylinder read 105 psi which was normal according to specs. But the lower cylinder read 80 psi. I don't know what is considered low psi but i think this is one is pretty low even if it can start and run. I am hoping the rings are sticking, possibly because no one had run it for many years. Or it might be the head gasket, because the previous owner took it off once to inspect the head. I took out the spark plugs and there was an orange kind of liquid on the bottom cylinder. (I hope it isn't rust). The top one had a brown tint to it. Maybe fogging oil? Also out of the exhaust, there was also a brown residue.
Right now, the weather in southern NC is unbearable and I also live near the beach so the humidity really makes you feel the burn. I am thinking about selling as parts and buying a new yamaha 4 stroke. Does anyone have any leads on working on an old outboard like this? I really don't want to give up a classic outboard like this.
I bought a jon boat (duracraft 1542) recently and it came with a 1985 yamaha 25HP tiller. Wanting to have a side console, I also bought a 1996 Yamaha 30HP (C30ELRU). It is the commercial 2 cylinder and has a single carburetor. Seller only wanted $650 for the listing. Came with control box and shift cables. He also said it only needed a carb job and spark plug change. He did some work and changed the CDI box. He also took the head off to see if there was any damage. Apparently there wasn't any. Said it was flooded before from the seller he bought. He didn't try running it and gave up because he wanted to buy a new four stroke. Willingly, I bought the outboard no questions asked. I didn't have a compression tester on me and the pull start felt like it had decent compression.
Took the carb off and cleaned the jet. Changed the spark plugs. Inspected the lower unit, and it had a brown color? It wasn't milky so the seals weren't blown I hope. I've used a brake tester, and the pressure stayed at 10psi. So lower unit is good. Hooked it up to the gas tank and battery. Turned the key and nothing happened. Sometimes I would get a click that kept repeating from the starter relay. I think it may be a battery related issue or bad connections. But the connections looked fine. After fiddling around, I got the starter to spin the flywheel. Maybe it was a bad connection. It took several tries to get it running but then it would stall after a few seconds. It would only run if I had the choke on and the high idle lever pulled out. And obviously, it is revving at high rpms. If I tried to lower the idle lever or choke, it would stall.
I waited a couple days because currently the weather is unbearably hot. I bought a compression tester from BlueDriver. (Harbor freight has bad reviews). The top cylinder read 105 psi which was normal according to specs. But the lower cylinder read 80 psi. I don't know what is considered low psi but i think this is one is pretty low even if it can start and run. I am hoping the rings are sticking, possibly because no one had run it for many years. Or it might be the head gasket, because the previous owner took it off once to inspect the head. I took out the spark plugs and there was an orange kind of liquid on the bottom cylinder. (I hope it isn't rust). The top one had a brown tint to it. Maybe fogging oil? Also out of the exhaust, there was also a brown residue.
Right now, the weather in southern NC is unbearable and I also live near the beach so the humidity really makes you feel the burn. I am thinking about selling as parts and buying a new yamaha 4 stroke. Does anyone have any leads on working on an old outboard like this? I really don't want to give up a classic outboard like this.