71 johnson 25 running issues

[jacobs05]

Engine will start up but dies, will not continue to run and will not run long enough to make any adjustments. Thanks

 

[gm280]

:welcome: jacob05 to iboats...

When you manage to get it started can you squeeze the primer bulb and keep it running? Check and post back...

 

[AlTn]

from a gentle seat, open the idle mixture needle 1 1/2 turns...will it remain running?..if not , open it another 1/4 turn and try....what is your starting procedure?...motor in neutral, throttle < twist grip > advanced as far as it will go?...< disregard the start position indicator on the tiller handle >..choke on full?...does it try to fire after 4 pulls or so?...if it does, go to 1/2 choke or fully off and it should start and run on the next pull...if it still won't start, post back for things to began checking

 

[jacobs05]

No results on keeping primer bulb pumped, idle screw must be hidden, not found. It will start on 2nd or 3rd pull but will die before I have a chance to throttle it up. Will not throttle up in neutral only in gear, when starts up it seems that it is idled up to high but only stays running for 2 seconds

 

[jacobs05]

Moving choke seems not to matter

 

[racerone]

????????---Low speed mixture screw is in plain view and is just above the carburetor throat !

 

[60sboater]

Maybe give the primer a few more squeezes after it's firm (maybe your carb is not filling up). Also,note if the primer indeed gets firm,somewhat firm,collapses. I have a 72 25 Johnson and pull choke closed and open after it is running a few seconds. It also takes 3 or 4 pulls.

 

[Johnson71]

I have the same motor with the same issues. I have been able to get the motor to stay running by pressing down on the throttle lever link, after which it will rev up, like you were rotating the tiller handle. Does your throttle lever open when you open the tiller all the way? Mine doesn't even come close. I suspect an issue with the throttle lever. (Just opened a new topic on this).

 

[jacobs05]

My starting procedure: Pull choke out, set throttle to start, pump bulb until hard, pull 2-3 times until engine starts, engine dies, tried moving choke and no difference, tried pumping bulb and no difference, broke handle and will have to replace it today if time allows. Took off carb. Saturday and took it out of soaking tank this morning and installed it. It had some black specks come out but not really dirty. Once I replace handle I will try moving throttle at carb. It can only be advanced at handle in gear . Thanks

 

[jacobs05]

I have the same motor with the same issues. I have been able to get the motor to stay running by pressing down on the throttle lever link, after which it will rev up, like you were rotating the tiller handle. Does your throttle lever open when you open the tiller all the way? Mine doesn't even come close. I suspect an issue with the throttle lever. (Just opened a new topic on this).

Throttle should not open all the way at handle unless it is in gear, not neutral.

 

[Johnson71]

I had success with my motor by doing the following- With the cover off, try starting your motor while holding your thumb on the throttle shaft arm. When you pull, press down on the arm, activating the throttle manually. If you get a response from the engine, the throttle shaft arm is out of adjustment. To adjust the throttle shaft, rotate the tiller handle so the throttle is all the way closed. Then loosen the throttle shaft arm screw and rotate the throttle shaft so that it is slightly open. Tighten the screw. This should allow the throttle to be activated at idle just enough for the engine to start and run. If you don't know what these parts are, you need to get a service manual. Best of luck!

 

[jacobs05]

Thanks,

 

[jacobs05]

I took carburetor off and soaked it for 3 days and installed, started up and runs OK but it is very smokey, seems to be running very rich.

 

[AlTn]

which parts of the carb did you disassemble prior to soaking for 3 days?...is the choke butterfly fully horizontal once it's started and running?...fuel mixture fresh and 50:1 ratio?....some other common problems..the gasket for the needle seat was left out...the nozzle, or boss, gasket is either missing or distorted...the float was installed upside down...the fuel pump is leaking from the rear of the pump body into the cylinder it draws its pulse from