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1978 Johnson 35 flooding

J

JohnBZ

New member
Hello, new to the forum ! I've owned a few older omc motors over the years. Used to have a 14ft Lund with a 1985 Johnson 25 on it. Switched to a riveted lowe 1648 mod V to have a little more room for hunting gear. Boat is a tiller with a 15" transom. Since I've had this boat it has had a 1973 evinrude 18, 1974 Johnson 25 and now has a 1978 Johnson 35 on it. I still have the 73 and 74 motors. I recently picked up the 35 for a little more power under heavy load while hunting. Got the motor for cheap knowing it would need some work. I put new plugs and lower unit oil in right away. The issue is that it is flooding badly and running rich. I had to adjust the throttle linkage to open the butterfly a little more at idle to even get the motor to start. I ran the motor Sunday morning on the water and it started with no choke on the second pull with a 22 degree air temperature. The motor will still idle with the slow speed needle valve back seated fully lean. The motor is hard to restart when warm. Plugs are both black. I pulled the carb apart and checked the float. It was level with the body and not leaking or punctured. I've got a carb rebuild kit on order. I'm thinking maybe the needle isnt seating properly and letting gas through all the time ? I've never seen a motor that if it doesnt start in a couple pulls needs the plugs pulled to get the liquid gas out of the cylinders. Also any recommendations on prop ? The prop on the motor is a 10.5x11 and is in poor shape from someone trying to cup it. I'm planning on replacing it with a primary goal of carrying a good load. My 1974 25hp pushes my boat around 20-22mph with 4 guys and a full hunting load with the high load prop. It takes forever to plane out. I'm not looking for miracles. Just to be able to plane out efficiently with a hunting load and get 25mph if possible. Thanks
 
Thermostat is ooerating okay. A new fuel pump is only a couple bucks more than a diaphragm so I added one to my order.
 
Replaced the fuel pump and rebuilt the carb today. Ended up about 2.25 turns out on the low speed needle. Engine actually needed choke to start ! Was able to get the motor to idle down much better. Hot start was easy with a partial pull. I need to get the throttle/timing advance dialed. I think it is still a bit too retarded. I need to get on the water to do some testing.i had to severely retard the timing to get it to run when it was flooding. Next step is a new prop. Top speed with the carb screwed up was 27. Hope to improve on that.
 
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