Dead in the water

[jeffmitchell]

Last weekend everybody is all excited about taking the boat out, new battery, couple of new cables, so I hook the hose up to it crank it (cranks beautifully) run on the water hose for a few minutes everything looks to be good. Everybody jumps in back it down the ramp in the water jump on and I crank the engine , this time I notice it doesn't seem to be a full power (running weak) I let it run a few minutes nothing changes , I try to go ahead and back off the trailer , it chokes off, will not start again, the motor will turn over but it sounds like no spark, it has new plugs as well, my question is , what is the most probable thing here coil pack, fuel pump, any suggestions?????????

120 hp Johnson outboard 1990 V4

 

[Joe Reeves]

Re: Dead in the water

And the engine is a.......................?

 

[jeffmitchell]

Re: Dead in the water

that would be good info, Johnson 120 hp outboard 1990 v4

 

[Joe Reeves]

Re: Dead in the water

Always start with the basics of troubleshooting.

Remove spark plugs, set them aside after inspecting their appearance. What did they look like.... any difference between any of them?

Check the compression of all cylinders. What are the individual readings?

With plugs still removed, check the spark. Rig a tester of some kind whereas you can set up a gap of 7/16" for the spark to jump. The spark must be a strong blue lightning like flame on all cylinders....... a real SNAP! Is it?

Drain some fuel from the carburetors to make sure that it doesn't contain water or a heavy concentration of oil. Let us know what you find there.

If all of the above areas are as they should be...... and if anyone has had the flywheel off recently, remove the flywheel again in order to inspect the flywheel key.

If the flywheel was not torqued properly, that allows the key to shear which throws the engine out of time instantly. If this is the case, clean the flywheel and crankshaft tapers thoroughly, install a new key so that the outer flat edge of the key is vertical with the engine.... NOT aligned with the crankshaft taper.... and torque the flywheel nut to factory specifications.

Let us know what you find.

 

[Mas]

Re: Dead in the water

New fuel for the season?

Mas