25hp 1955 Johnson, won't stay running!

Will Brad

Recruit
Joined
Apr 2, 2008
Messages
5
I have a 25 hp 1955 Johnson that wont stay running. I have used the it the past 3 years and have been pleased with its performance. Last year when I was out, it would not stay running in full throttle. I can get it to run if I spray in the carb but as soon as I stop spraying so does the motor? Any suggestions would be great!

Mod# RDE-17-C
Will
 

freddyray21

Commander
Joined
Jun 10, 2006
Messages
2,460
Re: 25hp 1955 Johnson, won't stay running!

check to see if the pressure tank is working correctly. A bad line from the manifold to the connector will cause a leak and it will only run on the fuel in the bowl. If it is getting gas to the carb then it might be time for a carb rebuild. If it has been converted the a fuel pump make sure the carb is getting gas.
 

Will Brad

Recruit
Joined
Apr 2, 2008
Messages
5
Re: 25hp 1955 Johnson, won't stay running!

Thank you both for your answers, I have replaced all lines in the motor and have had the carb rebuilt, I was told before about the length of the fuel/air lines from the tank that they had to be a certain lenght? Is this correct?
 

cc67

Petty Officer 1st Class
Joined
Nov 4, 2007
Messages
365
Re: 25hp 1955 Johnson, won't stay running!

Check the o-rings in the female fuel connector. Sounds like a fuel starvation problem. Make sure your gas tank cap is screwed on tight. I bought an RDE-17 today and It was having the same problem. It would run for a while and then it would die. As soon as you pumped the tank it would fire right up. Turned out to be a bad female fuel connector, just sucking air. They are neat motors. Good luck.
 

samo_ott

Vice Admiral
Joined
Jun 18, 2006
Messages
5,125
Re: 25hp 1955 Johnson, won't stay running!

Definitely sounds like fuel starvation. Either a leak as mentioned or maybe a clogged high speed jet. What happens when you adjust the high speed needle? It should be around 1.5 turns out from lightly seated.

Who rebuilt the carb and when?
 
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