1999 90hp Johnson... stalling out

[Ironsides]

gone...

[1730V]

First off, check your battery connections on both ends of the cables. Remove the cables from the battery and clean thoroughly. Do the same with the connections on the engine end of the cables.

[tashasdaddy]

as said check connections, also check the cables for any nicks, or swelling. was it running hot any alarms. check spark on all 4 next time it does it. could be power pack heating up and failing, did it just stop, like cutting off the key? do you have a kill lanyard, make sure it is not vibration and killing the motor.

[Ironsides]

gone...

[1730V]

[QUOTE=Ironsides;1502914]The connections aren't the cleanest I've seen them. QUOTE]

It may or may not run. Dirty connections (BOTH ENDS) can cause all kinds of issues.

My clue to this is that it did not want to turn over when it stalled. That's a classic symptom of a poor/intermittant battery connection. The biggest culprit is usually the negative battery terminal where it atttaches to the engine block.

[Ironsides]

gone...

[Ironsides]

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[1730V]

What you did was good preventive maintenance. Now, we get into some deeper diagnostics.

Are you running this on an inboard fuel tank? If so, does your primer bulb go flat when the engine acts up? If so, the anti siphon valve, on the outlet of the tank is sticking. Or, your fuel filter, if equipped, is clogged. Any marine store will have replacements, they are cheap. If that is not it, go to the next step below.

Do you have an inductive timing light? If not, borrow/rent one.

Once you have the light, put the inductive lead on each plug wire while the engine is acting up. This will tell you what cylinder is or is not firing. Once that is known, we can go further.

[Ironsides]

gone...

[tashasdaddy]

start from the basics. you know you have neglected the battery, and other things. start with on all 4 a compression check, and a spark check, with a spark tester, spark should jump 7/16 of and inch an be bright blue. with out these, there is not reason to go any further, until you find out why. the compression should be atleast 100 psi the higher the better, and within 10 % of each other. post your results back, and then whem we know you have a viable base to work with, we will go on.

[Ironsides]

gone...

[1730V]

and a little rusty.

Not good. "Rusty" indicates a head gasket or exhaust cover gasket problem. Neither are difficult or expensive to fix.