I recently bought a 1972 Chrysler 85 HP model 857HD. I took it out the first weekend with just fresh fuel mixture, fuel tank, and fuel line to the motor. Overall it ran pretty rough but it ran. We were able to get it cruising by finding the right rhythm for pumping the primer ball.
I took it home and put new fuel lines, plugs, and wires on it. Brought it back out to the lake the next weekend and it started right up and idled like a champ. The engine would run well up to about 1500 RPM. If we went above that it would start to go, almost die, go, almost die, repeat. All through this the primer bulb would never become fully firm. We fished for about 3 hours that day going in between spots cruising about 1200 rpms. At home that night I would pump the primer bulb and could watch gas go right out the exhaust onto the ground. We took off a vacuum line to the diaphragm and when pumping the primer bulb, gas would shoot out the vacuum line.
Deciding it was the fuel pump diaphragm, I finally got the diaphragm kit and replaced it yesterday. The old diaphragm definitely had some good rips on both sides. Once I got the pump back on, I pumped the primer and it became firm! The engine then started right up. I ran it for about 10 seconds revving it up to about 3000 rpms and back down before shutting it off since I didn't have the muffs on. I felt the cylinder heads and exhaust manifold, warm, but I could leave my hands on them. Later that evening I took it back to the lake to try it out and all it would do is turn over.
I charged the starter battery and did my best today. Starter turns, flywheel turns it over, but it won't fire. Assuming I somehow screwed up the pump I took the hose off leading into the top carb furthest from the fuel pump. As I turned the key, a good half inch bloop, bloop, bloop of gas would repeatedly come out of the line. I'm assuming that means I redid the pump correctly. Spark tester showed all 3 cylinders with a bluish spark that would jump 3/8"-1/2". Compression test on all 3 cylinders 140-150psi. I dropped a few drops of gas into the top 2 cylinders. With that it fired right up for 1-2 seconds then died. Neutral Interlock switch still works as well. The fuel primer bulb will stay firm and I can not pump excess fuel out of the exhaust like before.
I haven't redone the carbs yet. This is my first outboard and i'm not looking forward to getting them all synced back together, but i'm guessing that is where it is headed if everyone agrees or hopefully has better ideas! What has me baffled is how it idled very well before with a ripped diaphragm. Is it possible that the vacuum lines before were supplying fuel for idle and the carbs have been gummed up this whole time? Or has something else changed?
Sorry for being long winded. Trying to provide as much info as possible! Thanks!
I took it home and put new fuel lines, plugs, and wires on it. Brought it back out to the lake the next weekend and it started right up and idled like a champ. The engine would run well up to about 1500 RPM. If we went above that it would start to go, almost die, go, almost die, repeat. All through this the primer bulb would never become fully firm. We fished for about 3 hours that day going in between spots cruising about 1200 rpms. At home that night I would pump the primer bulb and could watch gas go right out the exhaust onto the ground. We took off a vacuum line to the diaphragm and when pumping the primer bulb, gas would shoot out the vacuum line.
Deciding it was the fuel pump diaphragm, I finally got the diaphragm kit and replaced it yesterday. The old diaphragm definitely had some good rips on both sides. Once I got the pump back on, I pumped the primer and it became firm! The engine then started right up. I ran it for about 10 seconds revving it up to about 3000 rpms and back down before shutting it off since I didn't have the muffs on. I felt the cylinder heads and exhaust manifold, warm, but I could leave my hands on them. Later that evening I took it back to the lake to try it out and all it would do is turn over.
I charged the starter battery and did my best today. Starter turns, flywheel turns it over, but it won't fire. Assuming I somehow screwed up the pump I took the hose off leading into the top carb furthest from the fuel pump. As I turned the key, a good half inch bloop, bloop, bloop of gas would repeatedly come out of the line. I'm assuming that means I redid the pump correctly. Spark tester showed all 3 cylinders with a bluish spark that would jump 3/8"-1/2". Compression test on all 3 cylinders 140-150psi. I dropped a few drops of gas into the top 2 cylinders. With that it fired right up for 1-2 seconds then died. Neutral Interlock switch still works as well. The fuel primer bulb will stay firm and I can not pump excess fuel out of the exhaust like before.
I haven't redone the carbs yet. This is my first outboard and i'm not looking forward to getting them all synced back together, but i'm guessing that is where it is headed if everyone agrees or hopefully has better ideas! What has me baffled is how it idled very well before with a ripped diaphragm. Is it possible that the vacuum lines before were supplying fuel for idle and the carbs have been gummed up this whole time? Or has something else changed?
Sorry for being long winded. Trying to provide as much info as possible! Thanks!
