Engine dies when put under load

[dhall95]

Runs full blast when water hose is on it, prop runs smooth.. but as soon as it is put in the river, you give it some throttle, it immediately dies.. I've heard 3 different opinions 1. Carbs need rebuilt 2.Impellor 3.fuel pump ,anyone else have an opinion on this? Also it is a 60 hp mercury

 

[lizardfish]

Re: Engine dies when put under load

what year?

 

[dhall95]

Re: Engine dies when put under load

what year?

1985

 

[James R]

Re: Engine dies when put under load

Chances are that one or more cylinders are not firing. Could be low compression,
poor or no spark, new plugs or wires needed, fuel not getting to the carbs, carbs need cleaning, synchronization is out, ignition timing is out.
a manual will certainly help.

 

[CharlieB]

Re: Engine dies when put under load

Keep racing that motor on the hose and you WILL be replacing it soon!

Verify spark by testing each cyl with an adjustable gap spark tester set to 7/16 inch. If all cyl's pass then start cleaning carbs.

This is assuming that you have already tested compression and all cyls are roughly even, within 10% of each other.

 

[dhall95]

Re: Engine dies when put under load

Keep racing that motor on the hose and you WILL be replacing it soon!

Verify spark by testing each cyl with an adjustable gap spark tester set to 7/16 inch. If all cyl's pass then start cleaning carbs.

This is assuming that you have already tested compression and all cyls are roughly even, within 10% of each other.

havin compression checked today, and a basic check up, should know tommaro

 

[dhall95]

Re: Engine dies when put under load

Turns out, only had 2 clylinders firing, compression was great.. had to order trigger assembly and stat assembly, were hoping that fixes it and gets #2 firing again.. if not im gonna have to change the electric box or that cdi thing, i really dont know what it is but the boat mechanic told me this..

 

[cannonford57]

Re: Engine dies when put under load

with only 1 cyl out not likely but not impossible trigger and stator are to blame.imho...good luck

 

[dhall95]

Re: Engine dies when put under load

with only 1 cyl out not likely but not impossible trigger and stator are to blame.imho...good luck

thats what i thought also, but the wiring was very brittle, and one wire between the stat and box was completely dry rotted and separated.. we tried a connector but still no fire on #2... so who knows. i hope this fixes it

 

[CharlieB]

Re: Engine dies when put under load

The stator on a 3 cyl feeds the box, period. If it fired ata ll, on any cyl's then the stator was working correctly. Flaky insulation was a future problem waiting to happen. Some have successfully RE-insulated the stator wires using a liquid plastic product like Dip-It, the tool handle coating.

Testing the trigger with a DVA Meter should show a lack of induced voltage which would NOT trigger the box to fire.

If the trigger and stator both check fine then the problem is either the coil or the box, then we test the coil, plug and wire, until we PROVE EVERYTHING good except the box. Buy NOTHING until proven bad.

Proper diagnostics is CRITICAL to saving you money on expensive NON-returnable electric parts.

If the new trigger does not cure your no fire on #2 then it is time to start looking for a new mechanic, or to purchase the manual and a few select tools.

We are here to guide you through the process of determining how to diagnose and repair your problems.