1994 Johnson 150

[jlwest63]

Going to look at a boat today. The owner says the motor runs real good but after you run it on the water for a little while it dies. Sometime it starts right back up, sometimes you have to wait 5min.

Any ideas where to start looking?

 

[muskrat]

Re: 1994 Johnson 150

any time you buy a outboard have it check out.have the compression checked,check & change gear oil.sounds like you have a ignition problem..

 

[tashasdaddy]

Re: 1994 Johnson 150

could be stuck float valve in the carb, running the gas out of it, and not refilling. try pumping the primer bulb when it starts to die, also could be fuel pump. could be coils, or power pack heating up and failing. see if the primer buld collapses when it starts to die, that would be a vent on the gas tank being clogged.

 

[jlwest63]

Re: 1994 Johnson 150

Compression test is good. 100 - 113 on all 6 cyls. The previous owner had no idea what it was. Can a shop check the ing. and coil packs if I take them to them?

Any other ideas on what it could be?

any time you buy a outboard have it check out.have the compression checked,check & change gear oil.sounds like you have a ignition problem..

 

[reeldutch]

Re: 1994 Johnson 150

if its ignition related just keep in mind to replace stator, pp and optical sensor and 3 siamese coils, new plugs and wires.
should run you about 500 dollars for a new system.

before you do this let a wrench who is familiar with omc optical ignition check it out.

thats probbebly worst case.

but like tashasdaddy said it could also be fuel related.
both systems should be checked.
i dont think you have a fuel restriction because there is a vacuum switch on the ois motors and would trigger the alarm.
stuck needle in a carb is possible but it would be very very strange to have this on all cylinders at the same time.

i would check the output of the fuel pump.
fuel pressure to the carbs.
powerpack spark if it dies?

we need more info .

does it stop after .......rpm
does it idle rough?
is the link and sync correct?
timing correct?
what spark plugs?
when it stops does it have spark?
when it stop are the plugs wet or dry?
does it die suddenly?
or more sputtering.

good luck

 

[jlwest63]

Re: 1994 Johnson 150

Here is an update.

Last night I blew out the vent tube, it did not seem plugged. Today I put in 6 new plugs, started it and let it run in the yard on muffs for a while and it ran fine. Then I figured I have a trolling motor so lets see what happens under load. Took it to the lake and ran it for about an hour, would stop, shut down, start back up go again, it ran perfect no problems and never once turned off.

I am going to have a mechanic tune it up and adjust the carbs anyway but it did not fail on me today once. ~ :/ ~

if its ignition related just keep in mind to replace stator, pp and optical sensor and 3 siamese coils, new plugs and wires.
should run you about 500 dollars for a new system.

before you do this let a wrench who is familiar with omc optical ignition check it out.

thats probbebly worst case.

but like tashasdaddy said it could also be fuel related.
both systems should be checked.
i dont think you have a fuel restriction because there is a vacuum switch on the ois motors and would trigger the alarm.
stuck needle in a carb is possible but it would be very very strange to have this on all cylinders at the same time.

i would check the output of the fuel pump.
fuel pressure to the carbs.
powerpack spark if it dies?

we need more info .

does it stop after .......rpm
does it idle rough?
is the link and sync correct?
timing correct?
what spark plugs?
when it stops does it have spark?
when it stop are the plugs wet or dry?
does it die suddenly?
or more sputtering.

good luck