1989 25 hp airflow

[norman2013]

Hey guys, I just purchased a 1989 johnson 25 hp motor model number j25elceb. I purchased it for dirt cheep and when the temp is 50 and above it runs great. But when it is below 50 into the 20s, it starts up great but dies out after 5-10 seconds. It looks to me that it is missing the airflow intake thing at the front of the carb. I will post a few pictures of it on this post. Please let me know if this air intake is needed for my motor to run in the cold. I was thinking about making a little plate that fits it perfectly to cover the carb end up and start with one hole drilled into it and drill more until proper airflow?

-- another thing when i was trying to get it to run fine in the cold, all i did was cover up the carb end with my hand and it ran fine.

 

[Bosunsmate]

Re: 1989 25 hp airflow

You could check that the thermostat isnt stuck open. The air intake shouldnt affect it that much

 

[jasper60103]

Re: 1989 25 hp airflow

I have basically the same motor. There's no air silencer on that model.

 

[Scott Danforth]

Re: 1989 25 hp airflow

the motor is cold, use more choke and throttle until it warms up

 

[norman2013]

Re: 1989 25 hp airflow



So this is normal?

 

[boobie]

Re: 1989 25 hp airflow

Yes........As said above, use more choke when it's cold.

 

[bonzoscott]

Re: 1989 25 hp airflow

I think that model has an electric primer instead of a choke. You may want to look towards that as your problem.

 

[Scott Danforth]

Re: 1989 25 hp airflow

guys, its a dumb motor with a simple carb.

EFI has spoiled the world and people forget how to run dumb small engines. if it runs right above 50 degrees, then there is NOTHING wrong with the motor. for when its cold, it needs more revs and more fuel just like your EFI motor does automatically in your car. normally its called a choke. call it an electric primer, it does the same thing. it richens the fuel mixture to about 10:1 for when the motor is cold. once the motor is warm, run it as normal.

 

[metriccrescentwrench]

Re: 1989 25 hp airflow

So this is normal?

All the carb engines I've had have been quite cold-blooded when the temperature drops. Learn to give it a shot of primer as it starts to die to keep it running, coupled with idling for a little while with bit of throttle until it warms up.

 

[norman2013]

Re: 1989 25 hp airflow

Ok, Thanks guys! I will give all of your suggestions a go around! Thanks

 

[F_R]

Re: 1989 25 hp airflow

You may have to experiment with different idle airflow orifices. Or at least try giving the idle mixture needle a tweak. Can't say that I have much experience with boating in temps in the 40's.