Johnson 25HP 1985

[Jay Jay]

Thanks to everyone that gave feedback about the fuel ratio, now the problem I have is that the engine starts and sounds great but after the initial revs it dies down and stops as if there is no fuel getting through but as soon as I turn the key again it starts and does the same thing, I have juat replaced the carb after taking it off and cleaning it in Acetone. Any ideas please

 

[Refueler]

If its a diaphragm carb ... the Acetone likely damaged the membrane ....

If its not diaphragm carb - then you have a blockage that is stopping carb from filling enough once started ... the carb is filling while you sort starting .. but then stops.

 

[VicS]

You do know how the primer (choke) works on electric start models? ... Red lever pointing back over the solenoid for normal automatic operation..

Check the fuel flow to the carb if you have any doubts but it should run for much longer than than you imply on a bowl full. Try repeatedly squeezing the bulb to see if tha keeps it going..
Also try keeping the primer (choke) energised for a little longer.but don't flood it.

I suspect the carb is not properly cleaned
Blow compressed air through all passages and clean the jets/orifices with a soft copper wire.
For a really thorough clean you may have to pry out the core plugs and replace with new from a carb repair kit

(part no 0392061 ... but check that's correct against your model number)

 

[Jay Jay]

You do know how the primer (choke) works on electric start models? ... Red lever pointing back over the solenoid for normal automatic operation..

Check the fuel flow to the carb if you have any doubts but it should run for much longer than than you imply on a bowl full. Try repeatedly squeezing the bulb to see if tha keeps it going..
Also try keeping the primer (choke) energised for a little longer.but don't flood it.

I suspect the carb is not properly cleaned
Blow compressed air through all passages and clean the jets/orifices with a soft copper wire.
For a really thorough clean you may have to pry out the core plugs and replace with new from a carb repair kit

(part no 0392061 ... but check that's correct against your model number)

Thanks very much for the info, the one thing I had no idea about was the red lever works thanks very much