Frosty Buds
Cadet
- Joined
- Mar 13, 2013
- Messages
- 8
1973 Johnson 50ESL73R 50hp Outboard
I'm posting here because I've tried everything I can think of or read about for the last 4 months to get this outboard running correctly. I can get it to fire up and run smooth at idle and run 3500 rpm's WOT but spits fuel out of the overflow tube when revved up. After a trip around the lake it drops idle and wants to stall or the rpms begin to increase and decrease in like a wave pattern, up and down up and down, but only while in gear.
I didn't have the needle clips for the carburetor needles so I used a small bit of wire to hold them to the float arm and it ran at 5000 rpm for about 1 min then began to pickup and lose rpms again. That was the first time it's ran up to 5000 rpms. Then for the first time it began to increase rpms out of gear and made docking difficult.
I've cleaned the carbs and rebuilt them.
Set the floats according to the manual.
Set the timing according to the manual.
Checked cylinder pressure: 140ish for both.
Getting good spark. I think.
Fuel pump looks new, diaphragm looks ok. I think. I'm going to replace this next.
I tried to adjust the low speed jets according to a guide I found here. I noticed once that the bottom carb jet didnt change the idle speed when turned in though.
I tried to eliminate the float height as the reason for the carbs (both of them are dumping fuel out of the overflow when revved and the butterfly valves when choked) by setting the low height (low fuel/open position) so that the needle barely moves or opens at all. This made no difference, they still are dumping fuel when choked and while revved.
Main symptoms:
Spitting fuel from overflow tube and dumping fuel from butterfly valves when choked
will not rev above 3000-3500 rpm
after running awhile begins to run unevenly
drops rpms at idle after running awhile
I'm at my wits end with this old motor. I hope one of you guys can recognize my problem from these symptoms. I will try to provide as much info as you need.
Thanks in advance.
I'm posting here because I've tried everything I can think of or read about for the last 4 months to get this outboard running correctly. I can get it to fire up and run smooth at idle and run 3500 rpm's WOT but spits fuel out of the overflow tube when revved up. After a trip around the lake it drops idle and wants to stall or the rpms begin to increase and decrease in like a wave pattern, up and down up and down, but only while in gear.
I didn't have the needle clips for the carburetor needles so I used a small bit of wire to hold them to the float arm and it ran at 5000 rpm for about 1 min then began to pickup and lose rpms again. That was the first time it's ran up to 5000 rpms. Then for the first time it began to increase rpms out of gear and made docking difficult.
I've cleaned the carbs and rebuilt them.
Set the floats according to the manual.
Set the timing according to the manual.
Checked cylinder pressure: 140ish for both.
Getting good spark. I think.
Fuel pump looks new, diaphragm looks ok. I think. I'm going to replace this next.
I tried to adjust the low speed jets according to a guide I found here. I noticed once that the bottom carb jet didnt change the idle speed when turned in though.
I tried to eliminate the float height as the reason for the carbs (both of them are dumping fuel out of the overflow when revved and the butterfly valves when choked) by setting the low height (low fuel/open position) so that the needle barely moves or opens at all. This made no difference, they still are dumping fuel when choked and while revved.
Main symptoms:
Spitting fuel from overflow tube and dumping fuel from butterfly valves when choked
will not rev above 3000-3500 rpm
after running awhile begins to run unevenly
drops rpms at idle after running awhile
I'm at my wits end with this old motor. I hope one of you guys can recognize my problem from these symptoms. I will try to provide as much info as you need.
Thanks in advance.