1996 125hp skip

[Triton19x2]

Don, I posted this on Sherm's Merc board but did not realize you monitored that board as well:

Sherm, a friend has a 1996 Merc 125 Serial # 0G383409. occasionally it will have a bad skip and it does not seem to happen with any warning. He has found that when it starts skipping, he can slightly turn the key towards the off position and it will clear up but all his gauges die. Is it a problem in the key switch?? If so, what would be the right part number for replacement? Any help would be appreciated

[EuropeanAM]

That does sound like a problem in the keyswitch.

In order to determine the correct part, we would need to know a little about his keyswitch "connections":

-Push on Spade Terminals?
-Screw-on ring Terminals?
-Molded in wiring?

[Triton19x2]

He is going to get the info to me tonight but I do know the switch is located in the "Quicksilver" control box with the shifter and throttle. I will post what he finds
Thx

[Triton19x2]

OK Don, he got back to me and said the wires coming out of the switch are molded and he thinks 3 go to a spaded connection and 2 are rings that are screwed together with 2 other black wires. It is a "Quicksilver" control box on a 1996 Procraft. Does that help?
Thx again

[EuropeanAM]

Part# 17009A5 would be a suitable replacement keyswitch.

[Triton19x2]

Don, thanks to you and Rhonda for the right part and FAST shipping on 4th of July weekend!
The part was installed yesterday and he ran the boat today.....new problem...go figure right?
Now the motor has an intermediate skip and it seems to happen at random RPM's. Once trying to get on pad the motor just shut off. It cranked right up and ran fine after that with occasional hesitation. My buddy did state that he needed to replace the spark plugs and did not know what the right one was. Can you give me direction on that?
One VERY important note to make: my buddy bought this boat used 4 years ago. It was in a boat house that had been struck by lighting. When he bought it he had to replace the stator and rectifier(I think). last year he replaced the power pack. As always thanks for the help

[EuropeanAM]

Start with the obvious- install correct spark plugs (NGK: BUHW-2).

Inspect voltage regulator for signs of burnt spots, melted, blackened, or browned connectors. If any of these are noted- REPLACE REGULATOR and any damaged connectors.

Check the cannon plug harness- clean the pins, CAREFULLY spread the male pins slightly, and reconnect. Ensure the cannon plug is firmly strapped in place to prevent vibration/loosening.

[Triton19x2]

Don, completed all the recommendations. Changed plugs, regulator and all wires look fine and it was changed when he bought the boat a few years ago. cleaned and slightly spread prongs on the cannon plug and secured. The problem still exist and I found out today that he can make it quit by doing the same thing with the key. If he slightly turns it towards off where all the gauges die, the motor clears up. Could it be a coil?? Not sure what else is left.

Thanks for the help

[EuropeanAM]

Based on your last description, I suspect you have a faulty ignition switch.

The switch may be intermittently providing some continuity on the "kill" circuit.

This interferes with (or completely eliminates in some cases) ignition system function.

Replacement switches are readily available.....

[Triton19x2]

Don, is the ignition switch different from the key switch that I just bought from you or is this something on the motor itself? New switch has been installed.
Thanks

[EuropeanAM]

Same switch- sorry, didn't put your switch purchase together with the post.

Does this rig have a TACHOMETER?

If so- try disconnecting the GRAY wire from the tach (isolate it with electrical tape), and then see if the problem persists.....

[Triton19x2]

Don, we tried disconnecting the gray wire from the tach and the problem is still there. Today the motor actually shut down at WOT and then cranked right back up with the skip. As usual a slight turn of the key and the motor clears right up but all gauges are off at that position. I thought about using a timing light next time to see if I can find a dead cylinder. what are your thoughts?
Thanks for time you spend helping us

[EuropeanAM]

This one is going to be very difficult to diagnose without something further to go on.

IF your boat were HERE.... the very next thing that would be done is:

-Attach a TEST HARNESS (transom-mounted keyswitch harness) directly to the engine, and run it to see if the problem persists. This would allow us to determine (with certainty) if the problem is INSIDE THE ENGINE COWLING (problem persists) or IN THE BOAT WIRING (problem disappeared with test harness).

BTW.... what type of boat is this on?

[Triton19x2]

Thanks Don, understood. The boat is a 1996 17 ft Procraft. I will relay the message to my buddy. He may just have to save up the money and take it to a real mechanic. Meanwhile he will have to keep my cell phone handy in case he needs a tow I will let you know what happens