CARB ADJUSTMENT '80 MODEL JOHNSON 25HP

[DANNY II]

I HAVE A 80 MODEL JOHNSON 25HP AND I AM HAVING A PROBLEM WITH THE CARB. IN ORDER FOR IT TO RUN I HAVE TO KEEP THE CHOKE ALL THE WAY OUT AND I NEED SOME INFO ON ASJUSTING THE CARB OR AT LEAST SOME SUGJESTIONS ON WHAT TO LOOK FOR. ALSO IN THE FRONT OF THE MOTER UNDER THE COWLING IT HAS A RICH TO LEAN ADJUSTMENT WHERE SHOULD I SET THAT?

 

[mikeyzx2]

Re: CARB ADJUSTMENT '80 MODEL JOHNSON 25HP

it's running lean if the motor can only run choked. have you overhauled the carb? and if I'm correct you're describing the slow-speed adjustment knob. <br />of course the book's all technical on setting the low speed knob:<br />1. warm to op. temperature, connect a tach, run engine at 700-750 rpm and adjust needle to produce highest rpm and smoothest operation. <br />2. then it says back needle out about 1/8 turn to prevent excessively lean condition at IDLE<br />3. run engine in FWD at idle and if tach doesn't show 650 rpm, adjust needle in to increase or out to decrease<br /><br />adjustments take a handful of seconds for engine to respond, keep that in mind<br /><br />I've heard the guys on here say to turn the needle in till it lightly seats then back it out about 1 1/2 turns as a starting point. do a search and see what you dig up

 

[DANNY II]

Re: CARB ADJUSTMENT '80 MODEL JOHNSON 25HP

THANKS FOR THE INFO HOWEVER I DO NOT HAVE A RPM GAUGE ON MY MOTOR. IS THERE A GAUGE THAT CAN BE HOOKED UP TO THE MOTOR SUCH AS A CODE READER ON A CAR?

 

[CATransplant]

Re: CARB ADJUSTMENT '80 MODEL JOHNSON 25HP

Not really...at least not for your 25 year old 25hp.<br /><br />If you're having to use the choke all the time, and the engine still won't run up fast, then you have bigger problems than a simple adjustment.<br /><br />You need a manual, first, then you can start diagnosing what's wrong with your outboard. Start, though, by checking all the fuel lines for air leaks. Then, pull the fuel hose off the carburetor and pull the motor through a few times and see if the fuel pump is delivering fuel to the carb.<br /><br />If it is, then it's probably time to do a carb cleaning and rebuild with a carb kit.<br /><br />By the way, you'll get a lot more answers here if you quit typing in all capital letters. That looks like shouting, and nobody wants to talk to someone who is shouting.<br /><br />A lot of folks who can help just don't bother to answer posts in all caps.

 

[DANNY II]

Re: CARB ADJUSTMENT '80 MODEL JOHNSON 25HP

sorry

 

[Blueclaw]

Re: CARB ADJUSTMENT '80 MODEL JOHNSON 25HP

check the easy things first.<br />Loosen the gas tank cap, and pump your bulb on you gas line and see if your motor runs normal. Sounds like a fuel delivery problem. tank vent, debri in the tank check valve, or screen. Bad o-rings in the gas line quick connects. Fuel filter?

 

[DANNY II]

Re: CARB ADJUSTMENT '80 MODEL JOHNSON 25HP

i defenatly had a problem there however i didnt think about it until about the third fishing spot the day it started acting up,(had to keep my priorties straight and fish no mater if the motor was running right or not) and i found it to be a bad connection at the tank. i repaired it and now it keeps good presure in the bubble. but the problem continued it is bogging down when i try to open up the throttle. i also think i might have fowled a plug. im going to change the plugs this weekend and try it again, after some test runs close to the dock, so i can try a few things to correct it. any ideas on what else to try?

 

[Blueclaw]

Re: CARB ADJUSTMENT '80 MODEL JOHNSON 25HP

the fouled plug will bog it down. Change your plugs then take it out. when it starts to bog pump the gas line priming bulb. see if that helps. the arrow on the bulb is pointing towards the motor isn't it? the quick connectors are on all the way?